Universe Today

There was a time when maps of the Moon were created from telescopic observations and drawings. Indeed Sir Patrick Moore created maps of the Moon that were used during the historic Apollo landings. Now researchers have enhanced a technique to create accurate maps from existing satellite images. Their approach uses a technique called ‘shape-from-shading’ and involves analyzing shadows to estimate the features and shape of the terrain. Future lunar missions will be able to use the maps to identify hazards on the surface making them far safer. 

Researchers at the Brown University in Rhode Island have helped refine a process used to map the surface of the Moon making it more accurate than ever before. In their paper, published in the Planetary Science Journal and authored by Benjamin Boatwright and team details the enhancements to the mapping technique. It can generate detailed models of the Moon’s surface to highlight craters, ridges and slopes from composites of 2D images. 

Closeup of lunar surface (Credit NASA)

Highly detailed maps are of crucial importance to lunar missions and help the planners to identify the safest place to land. They can also use them to identify areas of particular interest that require further study enabling the whole mission to be far more efficient. Missions such as the Artemis project will benefit when it heads for the south pole of the Moon, an area which is not well mapped. High resolution maps of the area will aid the autonomous landing systems to avoid hazards. 

Artist impression of Artemis lunar landing

Creating the maps is a time consuming job and is difficult to be accurate when lighting levels on target area are poor. The interpretation of shadows has been less than effective until now with the team addressing the issues. In their paper, the team explain how advanced computer algorithms can automate a lot of the process and improve the resolution of the generated models. Their new software gives lunar astronomers the necessary tools and information to create larger more detailed maps of the surface. 

To allow lunar scientists to create a map from images requires at least two images of the same area. Each image must be perfectly aligned with its counterpart so that features in one are in exactly the same place in the other. Until now, the technology has not been able to take multiple images of an area and create a perfect map. Boatwright said ‘We implemented an image alignment algorithm where it picks out features in one image and tries to find those same features in the other and then line them up, so that you’re not having to sit there manually tracing interest points across multiple images, which takes a lot of hours and brain power.’

Along with the image alignment algorithm, the researchers created quality control algorithms and filters to remove poor quality images from the alignment process. By only inputing good quality images to the process means the output will be of far higher quality. It is a similar model that astronomical imaging employs when processing multiple images through stacking and alignment techniques. 

To evaluate the accuracy of their work, the team compared the output from existing maps of the Moon to look for errors. To their delight, they found that maps created using their enhanced ‘shape-from-shading’ technique was more precise compared to those acquired during traditional techniques. 

Source : New technique from Brown University researchers offers more precise maps of the Moon’s surface

The post A New Way to Make Precise Maps of the Lunar Surface appeared first on Universe Today.

Six years after he announced a grand plan to fly around the moon with a crew of artists in SpaceX’s Starship rocket, Japanese billionaire Yusaku Maezawa said he was canceling the project due to delays in Starship’s development.

In a series of postings to the X social-media platform, Maezawa said he signed his contract with SpaceX “based on the assumption that dearMoon would launch by the end of 2023.”

“It’s a developmental project, so it is what it is, but it is still uncertain as to when Starship can launch,” he wrote. “I can’t plan my future in this situation, and I feel terrible making the crew members wait longer, hence the difficult decision to cancel at this point in time. I apologize to those who were excited for this project to happen.”

DearMoon crew member Yemi A.D., a Czech choreographer, talks about the mission’s cancellation.

After a selection process that attracted more than a million applicants, Maezawa named eight artists and communicators, plus two alternates, to the crew in late 2022. One of the chosen crew members was Tim Dodd, a science communicator and YouTube video creator who’s known as the “Everyday Astronaut.”

“Of course I’m extremely disappointed, having dreamt about this mission since I first heard about it in 2018 and even more for the last three years since the selection process started,” Dodd wrote in an extended posting to X.

Maezawa made his fortune by starting up what would become Zozo, Japan’s largest online clothing store. He sold most of his stake in the venture to Yahoo Japan in 2019 for around $2.3 billion. A fair amount of his riches has gone toward high-profile purchases, such as the $110.5 million acquisition of a painting by Jean-Michel Basquiat in 2017 and the estimated $80 million fare for a trip to the International Space Station in 2021.

The mega-launch system now known as Starship was at an early stage of development in 2018 when Maezawa struck a deal with SpaceX CEO Elon Musk to reserve a round-the-moon flight. The mission was envisioned as a roughly five-day trip that would give artists and performers on the level of Pablo Picasso and Michael Jackson the chance to experience space — and work that experience into their artistic creations.

The cost of the dearMoon project was never disclosed publicly, but at the time that the plan was revealed, Musk said Maezawa was providing a substantial deposit that “will have a material effect on paying for the cost of development” of the Starship system. Back then, Musk said the total development cost was on the order of $5 billion.

Developing and testing Starship has taken longer than Musk planned — which is par for the course when it comes to new types of spaceships. During the most recent Starship flight test, which took place in March, the rocket reached orbital altitude but broke up as it descended to a planned splashdown. Another flight test could take place as early as next week.

This isn’t the first time Maezawa has backtracked on his plans for spaceflight. In 2000, he pulled out of a reality-TV project that would have traced the selection of a female contestant to accompany him on a round-the-moon trip, presumably aboard Starship. Despite that precedent, the crew members for dearMoon said they were surprised by the cancellation of a trip they’d been so looking forward to.

“You didn’t ask us if we minded waiting or give us an option or discuss that you were thinking of canceling until you’d already made the decision,” Rhiannon Adam, an Irish-born photographic artist who was chosen for the crew, said in an X posting directed at Maezawa. “I can only speak for myself, but I’d have waited till it was ready.”

Another would-be spaceflier, night-sky photographer Brendan Hall, said in an online statement that “the cancellation of this mission was sudden, brief and unexpected.”

Dodd echoed that sentiment in his posting to X. “The one thing I have a hard time reconciling is the timeline,” he wrote. “Had I known that this could have ended within a year and a half of it being publicly announced, I would’ve never agreed to it. We had no prior knowledge of this possibility.”

Dodd said he remained optimistic about the long-term prospects for citizen spaceflight. “I still firmly believe that, within my lifetime, we will see missions like this happen, and while I will never be the first to do such a mission, it brings me great joy to know the future is bright and exciting,” he said.

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Universe Today has recently investigated a plethora of scientific disciplines, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, radio astronomy, extremophiles, organic chemistry, black holes, and cryovolcanism, while conveying their importance of how each of them continues to teach researchers and the public about our place in the vast universe.

Here, we investigate the field of planetary protection, which involves preventing Earth-born organisms from contaminating other worlds or interfering with scientific analyses on those worlds, along with preventing contamination to Earth from returned samples. To investigate this, we present a 2023 paper in Acta Astronautica with additional insights from the study’s lead author, Dr. Athena Coustenis, who serves as the Chair of the Committee on Space Research (COSPAR) Panel on Planetary Protection (PPP), regarding what planetary protection can teach us about finding life beyond Earth, exciting aspects about planetary protection, and advice for upcoming students who wish to study planetary protection.

The paper discusses the importance of planetary protection regarding space exploration, stating, “Planetary protection enables scientific return from solar system bodies investigations and at the same time protects life on Earth. As we continue to explore our solar system by landing machines and humans on other planets, we need to ascertain that we do not bring potentially dangerous material home to Earth or carry anything from Earth that may contaminate another planetary body and prevent scientific investigations.”

The paper discusses in greater detail the COSPAR PPP and its primary goals, including offering advice or guidance to government or private space-faring organizations and ensuring extraterrestrial samples returned from outer space do not contaminate the Earth, and specifically its biosphere. Additionally, the paper discusses recent policy actions taken by the PPP for the continued exploration of the Moon, Mars, and icy moons such as Europa, Enceladus, and Titan.

For the Moon, PPP recommended steps that need to be taken to prevent potential contamination of the permanently shadowed regions of the Moon, which are hypothesized to contain large quantities of water ice and are of significant interest for the upcoming Artemis missions. For Mars, the PPP focused on safeguarding more advanced scientific endeavors, including drilling, older areas of Mars that have yet to be explored, and sample return missions, to prevent contamination of potential scientific results and Earth’s biosphere, as well.

For icy moons, which the paper notes as being “possible habitable environments”, the PPP has already expressed concerns about exploring these worlds with the Planetary Protection of the Outer Solar System (PPOOS), which was led by the European Science Foundation and funded by the European Commission and is in the process of seeking additional insights in the future. Therefore, with these intriguing worlds being considered for exploration, what can planetary protection teach us about finding life beyond Earth?

Dr. Coustenis tells Universe Today, “Finding ways to preserve scientific research in our solar system helps the quest for finding life elsewhere and protecting our own biosphere during space exploration is essential for life on Earth. Working to that end with a large group of scientists, agency representatives and other expert stakeholders is one of the most rewarding activities in my career. The valuable outcome which represents thorough, long-term studies and reviews of knowledge is achieved through consensus and distributed to the large community. We are very excited to be able to offer such a service to the community via the COSPAR Panel on Planetary Protection.”

Along with serving as Chair of the COSPAR PPP, Dr. Coustenis has extensive research experience regarding planetary surfaces and atmospheres, specifically outer solar system objects like Europa, Ganymede, Titan, and Enceladus, as these worlds are targets for future astrobiology research. Additionally, Dr. Coustenis’ research extends far beyond the solar system as she has helped distinguish and characterize exoplanetary atmospheres, as well. Regarding planetary protection, some notable publications include being a co-author on a March 2024 paper discussing planetary protection for a future crewed Mars mission and a 2023 paper discussing COSPAR requirements for exploring Venus. Given her knowledge and experience regarding planetary protection, what are some of the most exciting aspects about planetary protection that Dr. Coustenis has encountered during her career?

Dr. Coustenis tells Universe Today, “We have recently worked on the Moon exploration requirements to preserve the poles and the regions where liquid water could be found at some periods of time and are currently working on the missions that will explore icy worlds, like the moons of our giant planets that harbor liquid water oceans underneath their surfaces, as well as organic chemistry and energy sources. These could be habitable environments that we need to explore with care.”

As noted in the Acta Astronautica paper, the field of planetary protection requires international collaboration not only from a multitude of scientists, but also engineers, as they are the individuals responsible for building the spacecraft that are sent to far-off worlds for scientific exploration. Other disciplines that contribute to planetary protection include geology, physics, geophysics, biotechnology, astrobiology, biomedical, planetary science. It is through this constant collaboration of scientists, engineers, and medical professionals that planetary protection has successfully prevented contamination of planetary bodies outside the Earth, but also preventing contamination of the Earth from returned samples. Therefore, what advice can Dr. Coustenis offer to upcoming students who wish to pursue a career in planetary protection?

Dr. Coustenis tells Universe Today, “Planetary protection offers the possibility to contribute coming from many different fields, scientific, engineering, economic or legal. We need all these varied points of view in order to accomplish adequate characterizations of space missions and related requirements and also to establish the real value of planetary protection, the enabling capacity of this tool and to spread the word about what we do and how others can contribute, in particular the younger generations. So, we encourage students and early-career space aficionados to join COSPAR and learn more about our work and that of other commissions and panels within its structure so as to be able also to position themselves and engage with the space community.”

How will planetary protection teach us about our place in the cosmos in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Planetary Protection: Why study it? What can it teach us about finding life beyond Earth? appeared first on Universe Today.

The Large Binocular Telescope (LBT), located on Mount Graham in Arizona and run by the University of Arizona, is part of the next generation of extremely large telescopes (ELTs). With two primary mirrors measuring 8.4 m (~27.5 ft), it has a collecting area slightly greater than that of a 30-meter (98.4 ft) telescope. With their resolution, adaptive optics, and sophisticated instruments, these telescopes are expected to probe deeper into the Universe and provide stunning images of everything from distant galaxies to objects in our Solar System.

An international team led by the University of Arizona recently acquired images of Jupiter’s moon Io that were the highest-resolution pictures ever taken by a ground-based telescope. The images revealed surface features measuring just 80 km (50 mi) across, a spatial resolution previously reserved for spacecraft. This includes NASA’s Juno mission, which has captured some of the most stunning images of Io’s volcanoes. These images were made possible by the LBT’s new SHARK-VIS instrument and the telescope’s adaptive optics system.

The team was led by Al Conrad, an Associate Staff Scientist with the University of Arizona’s Department of Astronomy, the Stewart Observatory, and the Large Binocular Telescope Observatory (LBTO). He was joined by researchers from the University of California, Berkeley, the California Institute of Technology, and NASA’s Jet Propulsion Laboratory. Their paper, “Observation of Io’s Resurfacing via Plume Deposition Using Ground-Based Adaptive Optics at Visible Wavelengths With LBT SHARK-VIS (GRL),” and the LBT images are set to be published in the Geophysical Research Letters.

The Large Binocular Telescope, showing the two imaging mirrors. Credit: NASA

SHARK-VIS is a high-contrast optical coronagraphic imaging instrument designed and built at INAF-Osservatorio Astronomico di Roma. The instrument is fed by the refurbished LBT extreme Adaptive Optics system, called the Single conjugated adaptive Optics Upgrade for LBT (SOUL). It was installed in 2023 on the LBT along with the near-infrared instrument, SHARK-NIR, to take advantage of the telescope’s outstanding adaptive optics system. The key to the instrument is its fast, ultra-low-noise “fast imaging” camera that captures slow-motion footage that freezes the optical distortions caused by atmospheric interference.

Gianluca Li Causi, the data processing manager for SHARK-VIS at the Italian National Institute for Astrophysics, explained how it works in a recent University of Arizona News release:

“We process our data on the computer to remove any trace of the sensor’s electronic footprint. We then select the best frames and combine them using a highly efficient software package called Kraken, developed by our colleagues Douglas Hope and Stuart Jefferies from Georgia State University. Kraken allows us to remove atmospheric effects, revealing Io in incredible sharpness.”

The SHARK-VIS image was so rich in detail that it allowed the researchers to identify a major resurfacing event around Pele, one of Io’s largest volcanoes located in the southern hemisphere near the equator (and named after the Hawaiin deity associated with fire and volcanoes). The image shows a plume deposit around Pele covered by eruption deposits from Pillan Patera, a neighboring volcano. NASA’s Galileo spacecraft observed a similar eruption sequence while exploring the Jupiter system between 1995 and 2003. However, this was the first time an Earth-based observatory took such detailed images.

An artist’s concept of the interior of Io. Credit: Kelvinsong/Wikimedia

“We interpret the changes as dark lava deposits and white sulfur dioxide deposits originating from an eruption at Pillan Patera, which partially cover Pele’s red, sulfur-rich plume deposit,” said co-author Ashley Davies, a principal scientist at NASA’s Jet Propulsion Laboratory. “Before SHARK-VIS, such resurfacing events were impossible to observe from Earth.” Io is the innermost of Jupiter’s largest moons (aka. Galilean moons), which include Europa, Ganymede, and Callisto. Since NASA’s Voyager 1 spacecraft flew through the Jupiter system in 1979, scientists have been fascinated by Io and its volcanic features.

Along with Europa and Ganymede, Io is locked in a 1:2:4 orbital resonance, where Europa makes two orbits for every orbit made by Ganymede, and Io makes four. Between its interaction with these moons and Jupiter’s powerful gravity, Io’s interior is constantly flexing, producing hot lava that erupts through the surface. While telescopes have taken infrared images that revealed hot spots caused by eruptions, they are not sharp enough to reveal surface details or identify the locations of the eruptions. By monitoring the eruptions on Io’s surface, scientists hope to gain insights into the tidal heating mechanism responsible for Io’s intense volcanism.

“Io, therefore, presents a unique opportunity to learn about the mighty eruptions that helped shape the surfaces of the Earth and the moon in their distant pasts,” said Conrad. Studies like this one, he added, will help researchers understand why some planets have active volcanoes while others do not. For instance, while Venus is thought to still be volcanically active, Mars is home to the largest volcanoes in the Solar System but is inactive. These studies may also shed light on volcanic exoplanets someday, helping astronomers to identify geological activity on distant planets (a possible indication of habitability).

SHARK-VIS instrument scientist Simone Antoniucci anticipates that it will enable new observations of objects throughout the Solar System with similar sharpness, revealing all manner of features that would otherwise require spacecraft.”The keen vision of SHARK-VIS is particularly suited to observing the surfaces of many solar system bodies, not only the moons of giant planets but also asteroids,” he said. “We have already observed some of those, with the data currently being analyzed, and are planning to observe more.”

Further Reading: University of Arizona

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It is truly wonderful to see so many nations aspiring to space exploration and trips to the Moon. Earlier this week on the 27th May, South Korea innaugurated its new space agency, the Korea AeroSpace Administration otherwise known as KASA. The group is headed up by former professor of aerospace engineering Yoon Young-bin. Whilst the group has yet to announce detailed plans for their upcoming missions Young-bin has stated they hope to land on the Moon by 2032 and to get to Mars by 2045.

The President of Korea, Yoon Suk-yeol, had confirmed that the government was committed to the space sector. To that end, they intend to secure investments of billions of dollars to fund the project. In March this year Korean Space Agency was formed in a ceremony that took place in March this year. Suk-yeol pleduged to facilitate 1,000 space companies and he hoped that 10 of the companies would become top-tier space firms. They would work hard to increase Korea’s share of the space market, aiming to hit 10% instead of the existing 1%. and create over 100,000 jobs. 

The Korean goverment has for sometime been keen to expand the space industry, Young-bin also prioritised support for the private sector. “The establishment of KASA will be an important stepping stone that guides the way for Korea to become a powerhouse in space economy by setting up the private-led space ecosystem,” Young-bin said. 

Young-bin is no stranger to space exploration since he had been researching space propulsion at the time of his appointment. His research chiefly focuses on liquid rocket engine. He has also been a serving director of the Institute of Advanced Aerospace Technology. 

Mid to long term goals and visions for space development are important next steps along the journey. To achieve those, KASA are striving for active cooperation from public, private and academic sectors. All of this is of course subject to securing the necessary funding. 

The framework for operations of KASA have been established and will be implemented with a maximum of 293 employees. Currenly only 110 are in place which includes a number of officials who were originally part of the Science Ministry in Korea. With the establishment of KASA, the Ministry of Science and ICT have been reorganised to align to their reduced scope of work but to find the remaining employees KASA will continue to search at home and abroad for the right people.

Along with their plans to explore the Moon and Mars, KASA is also planning to explore the Lagrangian Point known as L4. These regions in space lie along the Earth’s orbit and usually a little ahead or a litle behind but at these points, the gravitational force of the Earth and that of the Sun balance out against each other making for a highly efficient location for a probe. No country has acehived this yet so it will really put KASA on the international space exploration map.

They also plan to restore the Apophis mission which had been scrapped some years ago. The asteroid will pass close by Earth in 2029. The plan is for this to become an international mission, calling upon international co-operation. Other projects include participation in the Event Horizon Telescope and black hole imaging from one of NASA’s solar coronagraph.

Source : Korea ushers in new space era with KASA launch

The post South Korea is Planning to Send a Mission to Mars by 2045 appeared first on Universe Today.

How can machine learning help astronomers find Earth-like exoplanets? This is what a recently accepted study to Astronomy & Astrophysics hopes to address as a team of international researchers investigated how a novel neural network-based algorithm could be used to detect Earth-like exoplanets using data from the radial velocity (RV) detection method. This study holds the potential to help astronomers develop more efficient methods in detecting Earth-like exoplanets, which are traditionally difficult to identify within RV data due to intense stellar activity from the host star.

The study notes, “Machine learning is one of the most efficient and successful tools to handle large amounts of data in the scientific field. Many algorithms based on machine learning have been proposed to mitigate stellar activity to better detect low-mass and/or long period planets. These algorithms can be classified into two categories: supervised learning and unsupervised learning. The advantage of supervised learning is that the proposed model contains a large set of variables and has the ability to produce relatively accurate predictions based on the training data.”

For the study, the researchers applied their algorithm to three stars to ascertain its ability to identify exoplanets within the stellar activity data: our Sun, Alpha Centauri B (HD 128621), and Tau ceti (HD 10700), with Alpha Centauri B being located approximately 4.3 light-years from Earth and Tau ceti being located approximately 12 light-years from Earth. After inserting simulated planetary signals within the algorithm, the researchers found their algorithm successfully identified simulated exoplanets with potential orbital periods ranging between 10 to 550 days for our Sun, 10 to 300 days for Alpha Centauri B, and 10 to 350 days for Tau ceti. It’s important to note that Alpha Centauri B currently has had several potential exoplanet detections but non confirmed while Tau ceti currently has eight exoplanets listed as “unconfirmed” within its system.

Additionally, the algorithm identified these results correspond to Alpha Centauri B and Tau ceti potentially having exoplanets approximately 4 times the size of Earth and within the habitable zones of those stars, as well. After inserting more stellar activity data into the algorithm, the researchers discovered the algorithm successfully identified a simulated exoplanet approximately 2.2 times the size of the Earth while orbiting the same distance as the Earth from our Sun.

The study noted in its conclusions, “In this paper, we developed a neural network framework to efficiently mitigate stellar activity at the spectral level, to enhance the detection of low-mass planets on periods from a few days up to a few hundred days, corresponding to the habitable zone of solar-type stars.”

While the study focused on finding Earth-like exoplanets within RV data, the researchers note that additional data, including transit time, phase, and space-based photometry, could be used to identify Earth-like exoplanets. They emphasize the European Space Agency’s PLATO space telescope mission could accomplish this, which is currently being developed and slated for launch sometime in 2026. Upon launch, it will be stationed at the Sun-Earth L2 Lagrange point located on the opposite side of the Earth from the Sun where it scan up to one million stars searching for exoplanets using the transit method with an emphasis on terrestrial (rocky) exoplanets.

PLATO mission discussed around the 9:00 mark

This study comes as the number of confirmed exoplanets by NASA has reached 5,632 as of this writing, which is comprised of 201 terrestrial exoplanets, and also provides the upcoming PLATO mission ample opportunity to discover many more terrestrial exoplanets within our Milky Way Galaxy.

How will machine learning help astronomers detect Earth-like exoplanets in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post A New Deep Learning Algorithm Can Find Earth 2.0 appeared first on Universe Today.

Universe Today has had the privilege of spending the last several months venturing into a multitude of scientific disciplines, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, radio astronomy, extremophiles, organic chemistry, and black holes, and their importance in helping teach scientists and the public about our place in the cosmos.

Here, we discuss the intriguing field of cryovolcanism with Dr. Rosaly Lopes, who is the Directorate Scientist for the Planetary Science Directorate and a Senior Research Scientist at NASA’s Jet Propulsion Laboratory, regarding the importance of studying cryovolcanism, examples throughout the solar system, what cryovolcanism can teach us about finding life beyond Earth, exciting aspects of studying cryovolcanism, and advice for upcoming students who wish to study cryovolcanism. So, what is the importance of studying cryovolcanism?

Dr. Lopes references Geissler (2015) and tells Universe Today, “My colleague Paul Geissler defined it well: ‘The eruption of liquid or vapor phases (with or without entrained solids) of water or other volatiles that would be frozen solid at the normal temperature of the icy satellite’s surface’.

While we associate volcanism on Earth as being when hot magma erupts from the Earth’s interior into a fiery blaze and melting everything in its path, cryovolcanism is the study of ice volcanism, as “cryo” is defined as “ice cold” or “frost”. The term was first used in an abstract at the 1987 Geological Society of America (GSA) Abstract with Programs by Steven K. Croft and has since been used to describe ice volcanoes throughout the solar system. Additional terms used in the context of cryovolcanism include cryomagma and cryolava—comparable to magma and lava from traditional volcanoes—and cryovolcanic edifice—comparable to traditional shield volcanoes seen both on Earth and other planetary bodies (i.e., Mars and Venus). Therefore, what are some examples of cryovolcanism in our solar system?

Dr. Lopes tells Universe Today, “We see active cryovolcanism on Enceladus, and signs of past cryovolcanism on Titan, Europa, Ganymede, and even Io (SO2 rather than water).” Dr. Lopes elaborates more on active and past volcanism in a 2010 book chapter, as well.

The reason we see active cryovolcanism on Saturn’s moon, Enceladus, is due to the large liquid water ocean it possesses beneath its icy crust, with NASA’s Cassini spacecraft having not only imaged active plumes erupting from Enceladus’ south pole “Tiger Stripes”, but Cassini also flew through the plumes in March 2008, using its Ion and Neutral Mass Spectrometer (INMS) to identify water vapor, carbon dioxide, carbon monoxide, and organic materials, whose levels were higher than the Cassini team had hypothesized prior to the flyby.

Saturn’s largest moon, Titan, is home to bodies of liquid methane and ethane across its surface due to the frigid surface temperatures of -182.55 degrees Celsius (-296.59 degrees Fahrenheit), whereas methane and ethane exist strictly as gases on Earth. Regarding evidence for past cryovolcanism on Titan, the Cassini spacecraft discovered Doom Mons in 2005 and Erebor Mons in 2007, with both currently being generally accepted as cryovolcanoes. Additionally, Cassini used its radar instruments in 2018 to identify topography on Titan that was identified as the “very best evidence” for a cryovolcano on Titan.

Like Enceladus, Jupiter’s two Galilean Moons, Europa and Ganymede, have exhibited significant evidence that they both contain interior liquid oceans beneath their icy crusts, and NASA’s Europa Clipper mission is slated to launch this October to explore this icy world in detail once it arrives sometime in 2030. Additionally, the European Space Agency’s Jupiter Icy Moons Explorer (JUICE) mission launched in April 2023 with the goal of studying Ganymede in detail and is currently scheduled to enter Ganymede’s orbit sometime in late 2034.

Regarding evidence of past cryovolcanism on Europa, scientists postulated in 2020 that plumes observed to emanate from Europa could originate from directly within the icy crust. For Ganymede, specific surface features known as paterae have indicated “potential cryovolcanic regions”, but scientists remain skeptical and have listed these features as something the JUICE mission should investigate further.

Additional worlds in our solar system that also exhibit past or current evidence of cryovolcanism include the dwarf planet, Ceres; Neptune’s moon, Triton; the dwarf planet, Pluto and its moon, Charon; and other dwarf planets, as well. Therefore, with this plethora of worlds that exhibit current or past evidence of cryovolcanism within our solar system, what can cryovolcanism teach us about finding life beyond Earth?

Dr. Lopes tells Universe Today, “For life as we know it to exist, we need water and energy – cryovolcanism provides the heat (energy) and it is a way to bring material that may have biosignatures to the surface of bodies. If the material just stays in the ocean under an ice crust, it could be many decades before we are able to sample it.”

Regarding the most exciting aspects about cryovolcanism that she has studied during her career, Dr. Lopes tells Universe Today, “Finding Doom Mons and Erebor Mons on Titan was very exciting, as they are the most convincing evidence we have that cryovolcanism happened on Titan.”

Like the other scientific disciplines that Universe Today has explored, the field of cryovolcanism involves the collaboration of scientists from a multitude of backgrounds, including volcanology, planetary geology, physics, and computer science. Through this, scientists can create computer models of cryovolcanism based on existing data, along with using imagery from orbiters to confirm or update their models to ascertain the processes behind the cryovolcanism they have observed. Therefore, what advice can Dr. Lopes offer upcoming students who wish to study cryovolcanism?

Dr. Lopes tells Universe Today, “The physics of the process is still not well understood. Lab experiments are valuable. They should read the literature and figure out how to advance their understanding.”

How will cryovolcanism teach us about our place in the universe in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Cryovolcanism: Why study it? What can it teach us about finding life beyond Earth? appeared first on Universe Today.

Jupiter’s moon Io is a volcanic powerhouse. It’s the most geologically active world in the Solar System, sporting more than 400 spouting volcanoes and vents on its surface. Has it always been this way? A team of planetary scientists says yes, and they have the chemical receipts to prove it.

In a recent paper, the team headed by CalTech scientist Katherine de Kleer cites data from millimeter observations of elemental isotopes found in Io’s eruptions. They found that chemicals like chlorine and sulfur exist in higher quantities at Io than in comparable places in the Solar System. Analysis shows that Io hasn’t just started erupting lately—it’s been going on for most of its history. And, it’s so volcanic that it practically resurfaces itself every million years or so.

The discovery of volcanism on Io was one of the major results of the Voyager mission. As the two spacecraft swept past Jupiter in 1979, their images revealed Io’s volcanic features and plumes. Since that time, the Galileo, Cassini-Huygens, New Horizons, and Juno missions also sent images. The Jovian system and its moons are also frequent targets for ground- and space-based observatories, including Hubble Space Telescope and JWST.

Facts about Io

Io is the fourth-largest Jovian moon and is one of the four Galilean satellites. It orbits closest to Jupiter and gets pulled by a gravitational tug-of-war between Jupiter and the other Galilean moons. The result is a process called “tidal heating” deep inside Io, produced by friction. That generates heat, which melts Io’s interior, and opens up vents so that the heat and melted material can escape to the surface.

An artist’s concept of the interior of Io. By Kelvinsong – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=31526383

This little moon is mostly silicate rock atop an iron or iron sulfide core. The surface is scarred with volcanoes and deformed by compressional forces beneath the crust. The most obvious features are the volcanic mountains, plumes, and lava flows. Currently, Io’s volcanoes resurface the landscape at a rate of about 0.1 to 1.0 cm per year. They also paint its surface in an amazing array of colors. During the Voyager 2 flyby, people often compared its appearance to a pizza. The colors come mainly from sulfur and sulfurous compounds deposited across the landscape.

Normally, geologists would look at its surface and count craters to get an idea of its age. But, since volcanic flows erase craters, there’s no easy visual way to determine how long volcanic features have been around. However, it turns out that abundances of certain isotopes of sulfur and other elements could provide a good record the history of volcanism on Io.

Analyzing Io’s Chemistry

Io has probably lost mass to space throughout its history. de Kleer and her colleagues point out that its supply of volatile elements should be highly enriched in heavy stable isotopes. That’s because atmospheric escape processes generally favor the loss of lighter isotopes. They suggest that stable isotope measurements of volatile elements, such as sulfur and chlorine, could give accurate details about the history of volcanism at Io. So, it makes sense, then, to do a thorough chemical analysis of Io’s volcanic emissions now and extrapolate back.

Understanding Io’s current chemistry, requires, among other things, a good idea of its mass-loss history. Io’s mass loss occurs because of collisions between atmospheric molecules and energetic particles trapped in Jupiter’s magnetosphere. If this continued over Io’s history, then its chemistry should provide evidence of the volcanic past. In their paper, the team discusses the assumptions they made, including estimates of Io’s initial inventory of sulfur, as well as possible early mass-loss rates that could affect its current abundances of sulfur and chlorine—two elements that help determine past and present volcanism.

To get that history, team used the Atacama Large Millimeter Array to observe gases in Io’s atmosphere. The goal was to measure SO2, SO, NaCl, and KCl in various forms and determine the ratios of 34S to 32S and 37Cl to 35Cl. After analyzing the data, the team found that Io has lost at least 94 to 99 percent of its available sulfur over time. In addition, the measurements show enriched levels of chlorine. This probably indicates that Io has been volcanically active throughout time. It’s also possible that this tiny moon has experienced higher rates of outgassing and mass loss early in its history. More measurements should help scientists constrain Io’s volcanic activity even more tightly.

For More Information

Isotopic Evidence of Long-lived Volcanism on Io
Violent Volcanoes Have Wracked Jupiter’s Moon Io for Billions of Years

The post Io Has Been Volcanically Active for its Entire History appeared first on Universe Today.

There are some things that never cease to amaze me and the discovery of distant objects is one of them. The James Webb Space Telescope has just found the most distant galaxy ever observed! It has the catchy title JADES-GS-z14-0 and it has a redshift of 14.32. This means its light left when the Universe was only 290 million years old! That means the light left the source LOOOONG before even our Milky Way was here! How amazing is that!

The James Webb Space Telescope (JWST) with its 6.5m mirror was launched on 25 December 2021 and has quickly proven itself to be the most powerful space telescope ever built. It was designed to explore the Universe in visible and infrared radiation so that it could probe straight through dust to reveal hidden details behind. It is positioned at the second Lagrange point where the gravity of the Earth is balanced by the gravity of the Sun and it maintains a stable 1.5 million km from Earth. 

Artist impression of the James Webb Space Telescope

Over the last couple of years, astronomers have been using JWST to study the Cosmic Dawn! This period of time existed just a few hundred million years after the big bang but studying galaxies so far back in time required the sensitivity of the JWST. They provide valuable information about the gas and stars within and help to understand their formation. 

An international team were using JWST data that had been collected as part of the Advanced Deep Extragalactic Survey (JADES) using the Near-Infrared Spectrograph known as NIRSpec. They were able to acquire a spectrum of the galaxy revealing a redshift of 14.32. The redshift phenomenon occurs when the light from distant objects in space shift toward the red end of the spectrum. It was originally thought this was due to the movement but instead it is caused by the expansion of space. The greater the redshift, the faster the object is moving away and therefore the further away it is. 

The redshift of JADES-GS-z14-0 makes it the most distant galaxy known and it corresponds to the light having been emitted at a time when the Universe was just under 300 million years old. The team estimate the galaxy to be just over 1,600 light years across, that’s in comparison to the Milky Way which is thought to be 100,000 light years across. It is fairly typical of distant, early galaxies to be bright due to gas falling into a supermassive black hole but in the case of JADES-GS-z14-0 the light seems to be created by hot young stars. 

The image that has been released shows a field of thousands of distant galaxies of all manner of shapes, colours and sizes. One solitary bright star is visible in the foreground with the trademark diffraction spikes caused by the JWST optics. A box just to the lower right of centre highlights the location with the zoomed in image of the galaxy superimposed. The galaxy looks very different from those we tend to see in today’s Universe as it appears far less structured. 

Source : Webb finds most distant known galaxy

The post Webb Finds the Farthest Galaxy Ever Seen (So Far) appeared first on Universe Today.

On July 14th, 2015, the New Horizons spacecraft conducted the first-ever flyby of Pluto, which once was (and to many, still is) the ninth planet of the Solar System. While the encounter was brief, the stunning images and volumes of data it obtained revealed a stunningly vibrant and dynamic world. In addition to Pluto’s heart, floating ice hills, nitrogen icebergs, and nitrogen winds, the New Horizons data also hinted at the existence of an ocean beneath Pluto’s icy crust. This effectively made Pluto (and its largest moon, Charon) members of the “Ocean Worlds” club.

Almost a decade after that historic encounter, scientists are still making discoveries from New Horizons data. In a new paper, planetary scientists Alex Nguyen and Dr. Patrick McGovern used mathematical models and images to learn more about the possible ocean between Pluto’s icy surface and its silicate and metallic core. According to their analysis, they determined that Pluto’s ocean is located beneath a surface shell measuring 40 to 80 km (25 to 50 mi), an insulating layer thick enough to ensure that an interior ocean remains liquid.

Nguyen is a graduate student in Earth, environmental, and planetary sciences in Arts & Sciences at Washington University in St. Louis (WUSTL), while Dr. McGovern is a Senior Staff Scientist with the Lunar and Planetary Institute (LPI) in Houston. Their paper, “The role of Pluto’s ocean’s salinity in supporting nitrogen ice loads within the Sputnik Planitia basin,” recently appeared in the journal Icarus. The study is part of Nguyen’s Ph.D. research at Washington University, where he is an Olin Chancellor’s Fellow and a National Science Foundation Graduate Research Fellow.

This cutaway image of Pluto shows a section through the area of Sputnik Planitia, with dark blue representing a subsurface ocean and light blue for the frozen crust. Artwork by Pam Engebretson, courtesy of UC Santa Cruz.

For decades, planetary scientists assumed Pluto was far too cold to support an interior ocean. Pluto orbits well beyond the Solar System’s “Frost Line,” the boundary beyond which volatile elements (water, carbon dioxide, ammonia, etc.) become solid. With an average surface temperature of -229 °C (-380°F), even nitrogen and methane become as solid as rock. As Nguyen indicated in a recent interview with The Source (WUSTL’s news site), “Pluto is a small body. It should have lost almost all of its heat shortly after it was formed, so basic calculations would suggest that it’s frozen solid to its core.”

But thanks to New Horizons, scientists were presented with multiple lines of evidence that suggest Pluto likely has an interior ocean. This includes cryovolcanoes, such as those observed on Ceres, Europa, Ganymede, Enceladus, Titan, Triton, and other “Ocean Worlds.” While the existence of this ocean is still subject to debate, the theory is gaining acceptance to the point that it is considered a very real possibility. For their study, Nguyen and McGovern created mathematical models to explain the cracks and bulges in the ice covering Pluto’s Sputnik Planitia Basin.

Their results indicate that an ocean could exist beneath an icy shell 40 to 80 km (25 to 50 mi) thick, which would be sufficient to ensure that Pluto could maintain a liquid water ocean in its interior despite surface conditions. They also calculated the likely density or salinity of the ocean based on the surface features and determined that Pluto’s ocean could be up to 8% denser than Earth’s oceans. This salinity level would make Pluto’s ocean comparable to the Great Salt Lake, the Dead Sea, and other high-salinity bodies of water on Earth.

According to Nguyen, any variations in this density (greater or lower) would be evident from the cracks and fractures in the Sputnik Platina Basin. “We estimated a sort of Goldilocks zone where the density and shell thickness is just right,” he said. If the ocean were less dense, the ice shell would collapse, leading to many more fractures in the surface. If it were denser, the ice sheet would be more buoyed, which would be evident from there being fewer fractures. Unfortunately, it could be many decades before another spacecraft reaches Pluto to help confirm these findings. In the meantime, the case for Pluto’s interior ocean grows stronger!

Further Reading: Washington University at St. Louis, Icarus

The post Pluto Has an Ocean of Liquid Water Surrounded by a 40-80 km Ice Shell appeared first on Universe Today.

The earliest black holes in the Universe called primordial black holes (PBHs), are strong contenders to help explain why the Universe is heavier than it looks. There’s only one problem: these miniature monsters haven’t exactly been observed—yet. But, when astronomers do find them, they might turn out to be part of the Universe’s dark matter component.

Primordial black holes are one of several types of highly massive objects thought to exist in the Universe. We already know about stellar-mass black holes. They form during the deaths of hugely massive stars and generally end up containing up to dozens of solar masses. Then there are the supermassive black holes, embedded in the hearts of most galaxies. They sequester up to millions of solar masses.

The intermediate-mass black holes occupy the middle of the “black hole” spectrum. They’re another hot topic in black hole research circles. Appropriately enough, the masses of these black holes are between their stellar and supermassive counterparts. All these types of massive objects can collide with each other to grow bigger black holes. That generates gravitational waves that can be detected. The “ping” of each gravitational wave tells scientists a great deal about the objects colliding, including their masses.

How we might discover primordial black holes and help solve the dark matter mystery. Credit: ESA Understanding Primordial Black Holes in Context of Cosmic History

While astronomers search for PHBs, others are looking to explain why they might be part of the dark matter component of the Universe. In addition, they could explain the origin of binary black holes detected in gravitational wave observations.

A team of researchers at the University of Tokyo examined the “problem” of PBHs. Their work suggests that there should be far fewer of these objects than current models show. But, nobody knows how many existed back then. So, astronomers search them out using gravitational wave observatories. Their discovery should open a window on conditions in the early Universe when PBH formed.

These miniature ones are fascinating to think about. “Many researchers feel they are a strong candidate for dark matter, but there would need to be plenty of them to satisfy that theory,” said graduate student and team member Jason Kristiano. “They are interesting for other reasons too, as since the recent innovation of gravitational wave astronomy, there have been discoveries of binary black hole mergers, which can be explained if PBHs exist in large numbers. But despite these strong reasons for their expected abundance, we have not seen any directly, and now we have a model which should explain why this is the case.”

Modeling the Existence of Primordial Black Holes

The big question about PHBs: do (or did) they exist? And, can they be part of the dark matter component of the Universe? To answer that, Kristiano and his advisor Jun’ichi Yokoyama, searched through models of PBH formation. The best ones do not agree with the observed conditions of the leftover light fingerprint of the Big Bang. That’s called the cosmic microwave background (CMB). This is important, since PBHs formed in very early epochs of cosmic history, soon after the Big Bang. So, the team used the best model of PBH formation and applied quantum field theory to bring the model into alignment with reality.

Yokoyama explained the background behind their work. “At the beginning, the universe was incredibly small, much smaller than the size of a single atom. Cosmic inflation rapidly expanded that by 25 orders of magnitude. At that time, waves traveling through this tiny space could have had relatively large amplitudes but very short wavelengths. What we have found is that these tiny but strong waves can translate to otherwise inexplicable amplification of much longer waves we see in the present CMB,” said Yokoyama.

“We believe this is due to occasional instances of coherence between these early short waves, which can be explained using quantum field theory, the most robust theory we have to describe everyday phenomena such as photons or electrons. While individual short waves would be relatively powerless, coherent groups would have the power to reshape waves much larger than themselves. This is a rare instance of where a theory of something at one extreme scale seems to explain something at the opposite end of the scale.”

From Fluctuations to Miniature Black Holes

Those early small-scale fluctuations Yokohama describes affect some of the larger-scale fluctuations in the cosmic microwave background. Researchers can use measurements of wavelengths in the CMB to constrain the extent of corresponding wavelengths in the early Universe. That also puts some limits on any other phenomena that rely on the shorter, stronger wavelengths. And this is where the PBHs come back in.

“It is widely believed that the collapse of short but strong wavelengths in the early universe is what creates primordial black holes,” said Kristiano. “Our study suggests there should be far fewer PBHs than would be needed if they are indeed a strong candidate for dark matter or gravitational wave events.”

The next step relies on gravitational wave observatories and other types of observations. LIGO in the U.S., Virgo in Italy and KAGRA in Japan, are cooperating in observations aimed at finding the first PHBs. The results should help refine the ideas from Yokoyama’s team about PHBs and dark matter.

For More Information

The Case of the Missing Black Holes
Constraining Primordial Black Hole Formation from Single-Field Inflation
Note on the Bispectrum and One-loop corrections in Single-field Inflation with Primordial Black Hole Formation

The post Where are All the Primordial Black Holes? appeared first on Universe Today.

Astronomy is a profession that, so far, has only been done at night, at least on Earth. Light from the Sun overwhelms any light from other stars, making it impractical for both professional and amateur astronomers to look at the stars during daytime. There are several disadvantages to this, not the least of which is that many potentially exciting parts of the sky aren’t visible at all for large chunks of the year as they pass too close to the Sun. To solve this, a team from Macquarie University, led by graduate student Sarah Caddy, developed a multi-camera system for a local telescope that allows them to observe during daytime.

The University has a system known as the Huntsman Telescope, named after the famous Australian spider species. Its design was inspired by the Dragonfly Telescope Array, initially designed by researchers at the University of Toronto and Yale, among other institutions. Both telescopes feature an array of 10 telephoto lenses from Canon, the camera manufacturer, arranged in a honeycomb pattern.

Typically, the telescope is used for nighttime astronomy at the Siding Spring Observatory, about a seven-hour drive from Sydney. However, Ms. Caddy thought it could do better and potentially continue observations during the day.

An image of Betelgeuse during the day using the Huntsman Telescope.
Credit – Macquarie University

They originally tested their ideas, which focused on a number of broadband filters and a single-lens test version of the Huntsman telescope. This allowed them to optimize things like exposure times and timing and show a proof of concept that they then wrote up in a paper in the Publications of the Astronomical Society of Australia. 

In particular, Ms. Caddy and her colleagues are excited about several use cases. One is tracking particular stars that might soon undergo an exciting event. Betelgeuse comes to mind, as astronomers expect it to undergo a supernova sometime “soon,” though soon in astronomical terms could mean anywhere between tomorrow and 10 million years from now. If Betelgeuse happens to be on the other side of the Sun when it goes supernova, without daylight astronomy, there would be months of a gap where we would miss out on collecting data on the supernova that happened nearest to us in recorded history, and astronomers everywhere would be frustrated.

This is exactly why the Huntsman team used a daytime image of Betelgeuse as part of their proof of concept. While it might not look like a typical image of the star that is 650 light years away, the fact that it is visible at all during the daytime is striking.

Betelgeuse is one of the most interesting stars in the sky – a potential supernova that goes through occasional dimming periods, as Fraser explains.

Another use case is the tracking of satellites. As the orbital space around Earth becomes increasingly crowded, there’s a higher likelihood that satellites will begin colliding, which could eventually result in something as severe as Kessler syndrome, which we’ve discussed before here at UT. Unfortunately, astronomers can only track satellites during the night, so if one of their orbits happens to shift for some reason during a day cycle, it would be impossible for them to suggest changes to the orbital paths of other satellites that are close by.

Unless you have daytime astronomy, which allows you to track satellites during the day, there’s a significantly decreased risk of two running into each other unexpectedly. This data can be combined with radar readings to help avoid catastrophic collisions, no matter how crowded orbital space gets.

This proof of concept is a step toward making those observations a reality. As it is more fully tested, the southern sky will become much more accessible, and it could pave the way for other daytime astronomy projects in other parts of the world.

Learn More:
Macquarie University – Stargazing in broad daylight: How a multi-lens telescope is changing astronomy
Caddy, Spitler & Ellis – An Optical Daytime Astronomy Pathfinder for the Huntsman Telescope
UT – Astro-Challenge: Adventures in Daytime Astronomy
UT – Why Can We See the Moon During the Day?

Lead Image:
Macquarie’s Huntsman Telescope can potentially observe space during the day.
Credit – Macquarie University

The post A New Telescope Can Observe Even in Broad Daylight appeared first on Universe Today.

When the Arecibo Observatory dish in Puerto Rico collapsed in 2020, astronomers lost a powerful radio telescope and a unique radar instrument to map the surfaces of asteroids and other planetary bodies. Fortunately, a new, next-generation radar system called ngRADAR is under development, to eventually be installed at the 100-meter (328 ft.) Green Bank Telescope (GBT) in West Virginia. It will be able to track and map asteroids, with the ability to observe 85% of the celestial sphere. It will also be able to study comets, moons and planets in our Solar System.

“Right now, there is only one facility that can conduct high-power planetary radar, the 70-meter (230-foot) Goldstone antenna that is part of NASA’s Deep Space network,” said Patrick Taylor, the project director for ngRADAR and the radar division head for the National Radio Astronomy Observatory. “We had begun this process of developing a next generation radar system several years ago, but with the loss of Arecibo, this becomes even more important.”

The iconic Arecibo Radio Telescope, before its collapse in 2020: Credit: UCF

Planetary radar can reveal incredibly detailed information about the surfaces and makeup of asteroids, comets, planets, and moons. The ngRADAR system could provide unprecedented data on these objects. In fact, a recent test with a low-power prototype of ngRADAR at the GBT produced some of the highest resolution planetary radar images ever captured from Earth. But the hallmark of the new system will be seeking out near Earth asteroids and comets to evaluate any hazard they might present to our planet. 

“Radar is really powerful in determining the orbits of these asteroids and comets,” Taylor told Universe Today in an interview, “and the new system will deliver very precise data that will allow us to predict where these small bodies will be in the future. That will be one of the highest priority uses for the next generation radar system, where we can track and characterize near-Earth asteroids and comets to evaluate any hazard they might present to Earth in the future.”

A Radar Flashlight

Usually, radio telescopes collect weak light in the form of radio waves from distant stars, galaxies, and other energetic astronomical objects – including black holes or cold, dark objects that emit no visible light. While radio telescopes don’t take pictures in the same way visible-light telescopes do, the radio signals detected are amplified and converted into data that can be analyzed and used to create images. 

But radio telescopes can also be used to transmit and reflect radio light off planetary bodies in our Solar System. This is called planetary radar or Solar System radar.

This collage shows six planetary radar observations of 2011 AG5 a day after the asteroid made its close approach to Earth on Feb. 3, 2023. With dimensions comparable to the Empire State Building, 2011 AG5 is one of the most elongated asteroids to be observed by planetary radar to date. Credit: NASA/JPL-Caltech

What is planetary radar and how does it work?

“Essentially we have a flashlight that works in radio waves,” Taylor explained. “Our narrow flashlight beam does not look at the whole sky, but we point it in a very precise location – the surface of an asteroid or moon. We know very well what our flashlight’s properties are, so we know exactly what we send out. When we receive the echo back from wherever we pointed our flashlight, we analyze that signal and see how it changed compared to what we transmitted.”

That’s what makes planetary radar so powerful and different from any other type of astronomy.  

“When astronomers are studying light that is being made by a star, or galaxy, they’re trying to figure out its properties,” Taylor said. “But with radar, we already know what the properties of the signals are, and we leverage that to figure out the properties of whatever we bounced the signals off of. That allows us to characterize planetary bodies – like their shape, speed, and trajectory. That’s especially important for hazardous objects that might stray too close to Earth.”

In the past, planetary radar has been used to image asteroids, but also precisely measure the position and motion of the planets, allowing us to land spacecraft on Mars and to explore the outer Solar System. The technique has also made surprising discoveries, such as the finding the presence of water ice on Mercury.  

The 70m telescope at the Goldstone Deep Space Communications Complex in California’s Mojave Desert. (NASA/JPL)

Because radio waves are much longer than visible light waves, radio astronomy requires large antennas. The 70-meter Goldstone antenna located in California’s Mojave Desert, is primarily used to communicate with spacecraft as part of NASA’s Deep Space network. But it is also frequently used for planetary radar to study near Earth asteroids, and — as previously mentioned — is the only facility currently available to perform high-power planetary radar. (There are, however, are smaller facilities that can perform planetary radar, including smaller telescopes at the Goldstone site and a few in Australia, but they do not have the same scale of transmitter power as the Goldstone 70-meter dish.) Previously, the workhorse for planetary radar was the 1,000-foot-diameter (305 meters) Arecibo Observatory, which was about 20 times more sensitive and could detect asteroids about twice as far away than the Goldstone 70 meter.

However, because Arecibo’s dish was stationary and built inside a round sinkhole, it was fixed to the Earth and could only view whatever part of the sky happened to be straight overhead. That meant Arecibo’s dish could only see about one-third of the sky. Goldstone is fully steerable, can see about 80 percent of the sky, can track objects several times longer per day, and can image asteroids at finer spatial resolution.

ngRADAR

The Robert C. Byrd Green Bank Telescope is the world’s largest fully steerable radio telescope. The maneuverability of its large 100-meter dish allows it to quickly track objects across its field of view, and see 85% of the sky.

The GBT’s new radar system will introduce a high-resolution tool that will be a vast upgrade, collecting data at higher resolutions and at wavelengths not previously available. Scientists at GBT and the National Radio Astronomy Observatory (NRAO) are also developing advanced data reduction and analysis tools that have not been available before, providing astronomers with unprecedented planetary radar capabilities.

To test out the proof of concept, Taylor and his team worked with the company Raytheon — a long-time developer of radar systems for both the military and science applications — to build a small version of the transmitter, with a lot less power.

“Our friends at Raytheon built a transmitter that could output 700 watts, so about half the power of a microwave oven,” Taylor said. “Ultimately, we want to build a system with 500 kilowatts, so up by a factor of a thousand. But even with 700 watts, we were able to do some really impressive observations.”

Radar image of the Apollo 15 landing site. Credit: Raytheon/NRAO.

GBT’s planetary radar was aimed at the Moon, specifically at the Apollo 15 landing site in Hadley Rille, and at the giant Tycho Crater’s surface, and radar echoes were received with NRAO’s ten 25-meter VLBA antennas. At Tycho, the crater was captured with 5-meter resolution, showing unprecedented detail of the Moon’s surface from Earth. Taylor said the resolution with the ngRADAR prototype approached the optical resolution on Lunar Reconnaissance Orbiter, taking images with its high-resolution cameras from orbit around the Moon.

“The images of the crater floor were actually breathtaking,” Taylor said. “It’s pretty amazing what we’ve been able to capture so far, using less power than a common household appliance.”

A Synthetic Aperture Radar image of the Moon’s Tycho Crater, showing 5-meter resolution detail. Image credit Raytheon.

Additionally, the prototype radar also detected a potentially hazardous asteroid named (231937) 2001 FO32, which happened to be flying past Earth at about six times more distant than the Moon during their radar pings. The asteroid is considered potentially hazardous because of its size, approximately 1 kilometer in diameter, along with how close it can get to Earth, at just over 2 million kilometers away during the observations in 2021. The asteroid’s detection appeared as a spike in their data.

“Just from the spike in our data, we can now figure out how fast this object is moving, determine its orbit, and figure out its trajectory in the future,” Taylor explained. “We can determine its impact risk and assess how much of a hazard it is, and even constrain its spin state, its size, its composition, its scattering properties, and so on. So, even though the data spike doesn’t look like much, that one little detection can tell you a lot of information about the asteroid.”

Radar signals transmitted by the GBT will reflect off astronomical objects, and those reflected signals will be received by the Very Long Baseline Array (VLBA), a network of ten observing stations located across the United States.

“The idea is for GBT is to do the transmitting almost constantly and the VLBA — either all ten of those or any subset of those telescopes — doing the receiving,” Taylor said. “This new system will allow us to characterize the surfaces of many different objects in a different frequency or wavelength that hasn’t been used before.”

Next: Part 2 of this series will look at the details of ngRADAR, the history of planetary radar, and take you up close to the GBT.

The post Next-Generation Radar Will Map Threatening Asteroids appeared first on Universe Today.

Studying gas in the Universe is no easy task. We often look to ‘non-visible’ wavelengths of the electromagnetic spectrum such as X-rays. The Chandra X-Ray observatory has been observing a vent of hot gas blowing away from the centre of the Milky Way. Located about 26,000 light years away, the jet extends for hundreds of light years and is perpendicular to the disk of the Galaxy. It is now thought the gas has been forced away from the centre of the Milky Way because of a collision with cooler gas lying in its path and creating shockwaves. 

The Chandra X-ray observatory was launched by NASA in 1999. Since then, it has been orbiting above the atmosphere, probing space in high energy X-rays. It provides us with stunning, high resolution data that allows us to study black holes, supernova remnants and other high energy events in unprecedented detail. 

Artist’s illustration of Chandra

Using the power of the Chandra telescope to study the centre of our Galaxy, ridges that were perpendicular to the plane of the Milky Way were seen at a distance of 26,000 light years. The team of researchers believe the ridges are the walls of a tunnel that is shaped like a cylinder. The structure helps to funnel hot gas along, much as a chimney does over a fireplace, and away from the centre of the Galaxy. The vent is about 700 light years long and extends away from the core of the Milky Way. 

The structure was previously spotted using earlier data from Chandra but also from the XMM-Newton project too. The radio emission have been detected by the MeerKAT radio array ( based in South Africa this array is made up of 64 receivers ) too and shows the powerful effects of magnetic fields channeling gas along the chimney. Lead scientist Scott Mackey from the University of Chicago said “We suspected that magnetic fields are acting as the walls of the chimney and that hot gas is travelling up through them, like smoke.” He continued “Now we’ve discovered an exhaust vent near the top of the chimney.”

Exploring the Chandra data, the team think the vent formed from a collision as hot rising gas through the tunnel collided with cooler gas. The bright ridges in the walls are thought to be the result of shock waves generated by the collision. The left portion of the tunnel seems brighter because the gas flowing upwards has struck the chimney at a more direct angle and imparted more energy. 

As for the origins of the hot gas, it is thought this is coming from material falling into the black hole at the centre of the Galaxy. As material accretes around the black hole, a series of events can cause material to be ejected from the accretion disk, forcing the gas along the chimney.  X-ray flares are thought to take place every couple of hundred years near the black hole where blasts of X-ray radiation reflects off a build up of hot plasma. These flares are thought to drive the hot gas upwards and out through the vent. 

The diagonal line of bright objects in this image of the heart of our Milky Way Galaxy are all powerful sources of radio waves. The bright center is the home of the supermassive black hole, Sagittarius A*. The dense, bright circles are the nurseries of new, hot stars and the bubbles are the graveyards of exploded, massive stars. The thread-like shapes are not yet understood, but probably trace powerful magnetic field lines. This giant image was assembled from observations made by the Very Large Array (VLA).

One of the outstanding questions requiring extra research is the ultimate driving force behind the energy release. Is it a one off major event like the death of a star as it is ripped apart by the black hole or a series of smaller events that build up? Further studies are needed to fully understand the events at the centre of the Galaxy and to build a fuller picture of the nature of the vent at the centre of the Galaxy. 

Source : NASA’s Chandra Notices the Galactic Center is Venting

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As humanity returns to the Moon in the next few years, they’re going to need water to survive. While resupplies from Earth would work for a time, eventually the lunar base would have to become self-sustaining? So, how much water would be required to make this happen? This is what a recently submitted study hopes to address as a team of researchers from Baylor University explored water management scenarios for a self-sustaining moonbase, including the appropriate location of the base and how the water would be extracted and treated for safe consumption using appropriate personnel.

Here, Universe Today discusses this research with Dr. Jeffrey Lee, who is an assistant adjunct professor in the Center for Astrophysics, Space Physics & Engineering Research at Baylor University, and lead author of the study, regarding the motivation behind the study, significant results, the importance of having a self-sustaining moonbase, and what implications this study could have for the upcoming Artemis missions. Therefore, what is the motivation behind this study?

Dr. Lee tells Universe Today, “This paper is actually an eclectic diversion for me from my astrophysics research on primordial black holes, early universe cosmology, breakthrough propulsion physics, and my geophysics research on asteroid impacts. If human missions throughout the Solar System, particularly to Mars, are to be realized, then a permanent lunar facility seems to be a logical early step.”

For the study, the researchers investigated water management requirements for a 100-person self-sustaining lunar base measured at 500 m x 100 x 6 m (1640 ft x 328 ft x 20 ft), including the location of the lunar base near water ice deposits, the technology required to convert the water ice to water vapor (since liquid water can’t exist on the Moon), and the technology required for water treatment and recovery that would result in safe consumption for the 100-person base. The study used the current water usage estimates for American households, which is approximately 100 gallons per day (GPD) per person, which includes cleaning, cooking, drinking, flushing toilets, and washing clothes.

Additionally, the researchers examined the amount of water required for agricultural, technical, and overall needs for the lunar base. Regarding the location of the lunar base, the researchers deduced that the best location for the base would be either near, or exactly on, the Shackleton-de Gerlache Ridge, which is located at 89.9°S 0.0°E, or almost directly on the lunar south pole. The reason this location is ideal for water ice deposits is because Shackleton Crater resides within a permanently shadowed region (PSR), meaning it is shrouded in permanent darkness due to the Moon’s small axial tilt, and water ice has potentially built up over billions of years.

In the end, the team concluded the water requirements for the 100-person lunar base for human, agricultural, and technical needs are 12.3, 72, and 2 acre-feet per year. For context, one acre-foot is equivalent to approximately 326,000 gallons, so a 100-person lunar base would need more than 4,000,000 gallons per year for human needs, more than 23,000,000 gallons per year for agricultural needs, and 652,000 gallons per year for technical needs. So, based on these findings, what were the most significant results from this study, and what follow-up studies are currently in the works or being planned?

Dr. Lee tells Universe Today, “There is good evidence that sufficient water exists on the Moon to support a permanent lunar colony, and the acquisition, treatment, and distribution of the lunar water can be achieved with current technology. An appropriate administrative structure will be necessary to oversee all aspects of lunar water. The relative scarcity and management of water on the Moon can potentially provide insight for improving the management of water on Earth. The next study for my group will be to investigate the ways in which the management of lunar water could help to improve terrestrial water management. However, the timeline for this research is yet to be determined.”

The study discusses in-situ resource utilization (ISRU), which is using available, on-site resources for both sustainability and survivability. In this case, using water ice deposits on the Moon, and specifically near the south pole of the Moon, to meet the water needs of a 100-person, self-sustaining lunar base. The potential for NASA using ISRU has gained considerable traction in the last few years since sending water from the Earth to the Moon could prove to be extremely costly. But aside from the financial risks, if a resupply mission gets delayed or fails on the way to the Moon, the crew could face significant danger. Therefore, learning to “live off the land” for a lunar base could prove to be a viable, long-term option for mitigating the need of resupply missions from Earth. But what additional importance could a self-sustaining moonbase also provide?

Dr. Lee tells Universe Today, “Over the years, there has been a groundswell of excitement at the prospect of colonizing Mars. Indeed, at present, we are conceivably able to mount a short-term human voyage to the Red Planet in which the astronauts would collect samples, conduct experiments, plant flags, and when the next launch window occurs, return to Earth. However, the permanent colonization of Mars is much more ambitious and challenging. Mars is much farther away than the Moon, requiring 9 months to get there and a round trip time of 21 months (a 3-month stay on Mars is needed until the next launch window arrives).”

NASA’s goal is to send humans to Mars through the agency’s Moon to Mars Architecture, which is an elaborate, years-long endeavor to develop the necessary technologies on the Moon for use during a crewed mission to the Red Planet. This includes science, infrastructure, transportation, habitation, and operations, just to name a few. However, as noted, while we can (possibly) send humans to the Red Planet for short-term stays with our current technology, a long-term human presence on Mars would require significantly more time and resources.  

Dr. Lee tells Universe Today, “Beyond low Earth orbit, the Moon is a logical next destination. Lunar colonization is technologically achievable, and in comparison to Martian colonization, it is far easier. Being capable of establishing a moonbase seems like an obvious prerequisite for establishing a Mars base. Furthermore, the Moon would be an excellent jumping off point for further Solar System colonization including potentially the eventual establishment of small colonies in the interiors of Near-Earth Asteroids. Additionally, some have suggested that the Moon is an ideal location from which the interception of Earth-bound asteroids could be conducted.”

This study comes as NASA’s Artemis program plans to land the first woman and person of color on the lunar surface in the next few years. The current landing sites of the Artemis missions are near the south pole to access nearby water ice deposits within the aforementioned PSRs and could be ideal to develop ISRU technologies that can also be used on future Mars crewed missions, as well. Therefore, what implications could this study have for the upcoming Artemis missions?

“Short term lunar visits, such as the planned Artemis missions would not require lunar water,” Dr. Lee tells Universe Today. “In these instances, sufficient water could be brought from Earth. However, if at some point in the future, a lunar colony were to become a priority, future Artemis missions could serve to provide valuable in situ information about the presence and abundance of lunar water, particularly at the lunar south pole and in proximity to the Shackleton Crater (an ideal area for a moonbase).”

How will water management play a role in a self-sustaining lunar base in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post How Much Water Would a Self-Sustaining Moonbase Need? appeared first on Universe Today.

Over the last few months, Universe Today has explored a plethora of scientific fields, including impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, cosmochemistry, meteorites, radio astronomy, extremophiles, and organic chemistry, and how these various disciplines help scientists and the public better understand our place in the cosmos.

Here, we will discuss the fascinating and mysterious field of black holes with Dr. Gaurav Khanna, who is a Professor in the Department of Physics at the University of Rhode Island, regarding the importance of studying black holes, the benefits and challenges, exciting aspects of studying black holes, and how upcoming students with to pursue studying black holes. So, what is the importance of studying black holes?

“Gravity is the oldest known, but the least understood force in nature,” Dr. Khanna tells Universe Today. “For students of gravity, black holes are amongst the most interesting objects to study because gravity is the dominant force there — in fact, it is infinitely strong! Then there are astrophysical reasons of interest in black holes. They play important roles in galaxies, perhaps even in the large-scale behavior of the universe and more. The other thing to note about black holes is that they are very ‘simple’ especially when compared to stars and other astrophysical objects. This is a consequence of the so-called ‘no hair’ theorem that states that black holes can be fully characterized by only 3 attributes — their mass, charge and spin. That simplicity makes them particularly appealing to study and research.”

Black holes are known for exhibiting gravity so strong that light can’t even escape, and while Albert Einstein’s theory of general relativity in 1915 is often credited with first proposing the concept of black holes, the concept of an object whose size and gravity would not allow light to escape was first proposed in a November 1784 letter by English philosopher and clergyman, John Mitchell. In this letter, Mitchell referred to these objects as “dark stars” since he postulated that stars whose diameters exceeded 500 times that of our Sun’s diameter would trigger the formation of these objects. Additionally, he suggested that gravitational waves influencing nearby celestial bodies would enable these objects to be detected.

Fast forward to Einstein’s theory of general relativity, which also predicted both the existence of black holes and gravitational waves, both of which continued to be scrutinized throughout the 20th century, which includes what’s called the “golden age of general relativity” during the 1960s and 1970s. This includes the first object accepted by the scientific community as a black hole, called Cygnus X-1, which was discovered in 1964. However, it took another 52 years for the existence of gravitational waves to be confirmed through a black hole merger, which was accomplished by the LIGO Scientific Collaboration. Therefore, given the extensive history combined with key discoveries only occurring within the last few years, what are some of the benefits and challenges of studying black holes?

Dr. Khanna tells Universe Today, “As I stated above, studying black holes, which are a consequence of Einstein’s relativity theory, offers insight on the nature of gravity, space and time at the most fundamental levels. As physicists, we are yet to develop a complete understanding of the quantum nature of gravity, and black holes are the key to unlocking that mystery. On the challenges, I’d say that the clearest one perhaps is that black holes can only be observed indirectly. Unlike stars, since they don’t emit radiation themselves, it is difficult for astronomers to collect data on them. At best, we can observe their influence on their environment (like gas, stars, etc.) and infer their properties and behavior. On the theoretical side, while it is indeed true that black holes are very “simple” compared to stars, there are still challenges. The mathematics and physics that describe them is fairly advanced and even computer simulations involving them are challenging requiring massive processing power and memory.”

While it took over 100 years between Einstein introducing his theory of general relativity in 1915 and the confirmation of gravitational waves in 2016, it only took another three years for astronomers to publish the first direct image of a black hole at the center of the Messier 87 galaxy. The results were published in The Astrophysical Journal Letters and based on observations taken in 2017 by the powerful Event Horizon Telescope (EHT). While Messier 87 is located approximately 53 million light-years from Earth, the closest hypothesized black hole, Gaia BH1, is located approximately 1,560 light-years from Earth. In 2022, astronomers published a direct image of Sagittarius A*, which is the supermassive black hole at the center of our Milky Way Galaxy.

Additionally, scientists hypothesize the number of black holes in our Milky Way Galaxy is in the hundreds of millions, despite only a few dozen known black holes having been confirmed, thus far. But what are the most exciting aspects about black holes that Dr. Khanna has studied during his career?

Dr. Khanna tells Universe Today, “I suppose I’d probably refer to my recent work on how very rapidly rotating black holes attempt to ‘grow hair’ but ultimately fail. The project is interesting because it appears to suggest a violation of the ‘no hair’ theorem that I mentioned earlier, but it ultimately doesn’t. So, it is provocative, but then relieving! More importantly, we are now using the main context of that research to develop a new observational ‘signature’ or test for rapidly rotating black holes, a.k.a. near-extremal black holes. Such black holes have several peculiar properties and aspects and are an area of active research.”

Black holes are studied by astronomers, physicists, and astrophysicists, who use a combination of theory and observations to construct what black holes might look like, and in rare cases, as discussed, obtain direct images of them. Regarding theory, researchers use mathematical calculations and computer models to simulate what black holes might look like, and then have used powerful ground-based telescopes like EHT to obtain the few direct images of black holes. It is important to note that these direct images don’t capture the black hole itself, but the gases that are encircling the black hole’s event horizon, or the unofficial boundary where light can’t escape the black hole. But what advice can Dr. Khanna offer upcoming students who wish to pursue studying black holes?

Dr. Khanna tells Universe Today, “I would offer them a lot of encouragement! There is a lot to do in this space and many mysteries to solve. New observations are going to open many new doors and brand-new avenues for research. This is amongst the best times to be a black hole astrophysicist!”

Dr. Khanna continues, “The one thing that I could say perhaps that isn’t as much emphasized elsewhere is about computing as a tool to study black holes. Mostly there is heavy emphasis on learning advanced mathematics as the background for serious research in black holes — and for good reason — that continues to be critical for every student of Einstein’s relativity theory which is the foundation for black hole physics.  In recent years, computer simulations have advanced rapidly, and one can now make major discoveries about deep questions using computational tools. In the long run, computer programming would be a very promising tool for advancing research in this field and many others as well.”

How will black holes help us better understand our place in the universe in the coming years and decades? Only time will tell, and this is why we science!

As always, keep doing science & keep looking up!

The post Black Holes: Why study them? What makes them so fascinating? appeared first on Universe Today.

Dyson Spheres have been a tantalising digression in the hunt for alien intelligence. Just recently seven stars have been identified as potential candidates with most of their radiation given off in the infrared wavelengths. Potentially this is the signature of heat from a matrix of spacecraft around the star but alas, a new paper has another slightly less exciting explanation; dust obscured galaxies. 

There are a number of ways to hunt for aliens and one of them is to look for signs of large scale projects in space. Enter the Dyson Sphere. The idea was first proposed by Freeman Dyson in 1960 to describe that an advanced civilisations would position power collectors and even habitats around a star to harness its power. Eventually such infrastructure would likely surround the entire star and Dyson reasoned that a signature would be detectable such as an excess of infrared radiation. 

A Type II civilization is one that can directly harvest the energy of its star using a Dyson Sphere or something similar. Credit: Fraser Cain (with Midjourney)

The findings of Project Hephaistos revealed the seven M type stars from a sample of 5 million stars detected by Gaia. The astrometric satellite has been used to map stars in the Milky Way and has been of profound benefit to many pieces of research. Data from 2MASS (the Two Micron All Sky Survey) and WISE (the Wide Field Infrared Survey Explorer) were also used to identify the stars that seemed to display the expected Infrared excess. 

Artist’s impression of the Gaia spacecraft detecting artificial signals from a distant star system. In this synchronization scheme, the star system’s inhabitants send the signal shortly after witnessing a supernova, which is also seen by telescopes on Earth. (Credit: Danielle Futselaar / Breakthrough Listen)

In the recent paper by lead author Tongtian Ren and team, they explore the findings of the project and delve into the possible nature of the candidate spheres. The team cross-matched the information from data from the Very Large Array Sky Survey (VLASS) and several other radio surveys of the sky. They searched for radio sources within a radius of 10 arc seconds of the Gaia positions of the candidates. Note that the full Moon is 1,860 arc seconds across. 

Radio sources were found for three of the candidates, those named A, B and G. The accuracy of the sources was within 4.9, 0.4 and 5 arc seconds respectively and candidate G was found in multiple radio surveys. The conclusion from the team is that the seven stars are less likely to be Dyson Spheres but instead some sort of extra galactic phenomenon. The most likely explanation is a distant galaxy obscured by dust! The presence of the dust would contaminate the Infrared energy distribution in the spectra of the two objects. The other candidate, candidate B is also thought to be a distant galaxy but one that was within very close line of sight of an M type dwarf star. 

Very similar to candidates A and B, candidate G has a spectrum that reveals a radio loud active galactic nuclei with superluminal jets extending out. It is likely that galaxies are distant quasars which emit enormous amounts of radiation, but the obscuring hot dust clouds obscure most radiation, except infrared. 

What of the other four candidates? To date, no matching radio source has been found. That does not mean the hot, dust obscured galaxy model is not an adequate explanation but just that possible higher resolution radio surveys are required. Of course it may also be that they really are spheres of technology around distant stars. As much as I would love that to be true, there is no evidence for this yet. 

Source : Background Contamination of the Project Hephaistos Dyson Spheres Candidates

The post There’s Another, More Boring Explanation for those Dyson Sphere Candidate Stars appeared first on Universe Today.

The lifecycle of a star is regularly articulated as formation taking place inside vast clouds of gas and dust and then ending either as a planetary nebula or supernova explosion. In the last 70 years however, there seems to be a number of massive stars that are just disappearing! According to stellar evolution models, they should be exploding as supernova but instead, they just seem to vanish. A team of researchers have studied the behaviour of star VFTS 243 – a main sequence star with a black hole companion – and now believe it, like the others, have just collapsed, imploding into a black hole!

During the life of a star, the inward pulling force of gravity is balanced by the outward pushing thermonuclear force (the result of fusion in the core.) Once the core is rich in iron, as happens with massive stars about 8 times more massive than the Sun, the fusion process ceases as does the thermonuclear force. With the cessation of the force, the core collapses, the outer layers collapse in on the core and bounce back out as a massive explosion known as a supernova. The actual mechanism of the explosion and the formation of the compact object that is left behind from the core is still the subject of a lot of debate. 

The supernova process is one of the most powerful explosions in the universe. As the star collapses, a shockwave is produced that can create fusion in the outer shell of the progenitor star. The reactions can create new elements heavier than iron. In a paper recently published by an international team of astronomers led by Alejandro Vigna-Gómez from the Max Planck Institute for Astrophysics in Germany the team shed new light on the process. They showed that it is possible for a star to be so massive that its gargantuan force of gravity can be strong enough that even the supernova explosion is not able to take place.

The Fred Lawrence Whipple Observatory’s 48-inch telescope captured this visible-light image of the Pinwheel galaxy (Messier 101) in June 2023. The location of supernova 2023ixf is circled. The observatory, located on Mount Hopkins in Arizona, is operated by the Center for Astrophysics | Harvard & Smithsonian. Hiramatsu et al. 2023/Sebastian Gomez (STScI)

The team’s discovery seems to be linked to the concept of disappearing stars. Over the last few years, it has become evident that some stars seem to just vanish from view, neither passing through the planetary nebula phase nor going supernova. The discovery of supermassive stars undergoing complete collapse without supernova now provides a good explanation for the phenomenon. 

The team reached their conclusion when they explored an object known as VFTS 243; a binary system which includes a star thought to be 25 times more massive than the Sun and a blackhole 10 times more massive than the Sun. Both objects orbit a common centre of gravity over a period of 10.4 days and lie in the Tarantula Nebula in the Large Magellanic Cloud – 160,000 light years away. The binary system is not the first of its kind to be discovered, such systems have been known about for decades. 

30 Doradus, also known as the Tarantula Nebula, is a region in the Large Magellanic Cloud. Streamlines show the magnetic field morphology from SOFIA HAWC+ polarization maps. These are superimposed on a composite image captured by the European Southern Observatory’s Very Large Telescope and the Visible and Infrared Survey Telescope for Astronomy. Credit: Background: ESO, M.-R. Cioni/VISTA Magellanic Cloud survey. Acknowledgment: Cambridge Astronomical Survey Unit. Streamlines: NASA/SOFIA

Studying the system revealed the orbit was almost circular. Given that one of the stars had collapsed into a black hole, the nearly circular orbit and the lack of any evidence of an explosion all point to a star that collapsed completely. The complete collapse meant that all matter from the star collapsed into the blackhole and no material escaped out as a supernova. Could it be then that the team have finally revealed the mechanism by which massive stars have been vanishing? It certainly looks like it but further observations of binary systems with stars and black holes is required to confirm. 

Source : Constraints on Neutrino Natal Kicks from Black-Hole Binary VFTS 243

The post Hundreds of Massive Stars Have Simply Disappeared appeared first on Universe Today.

Human visitors to Mars need somewhere to shelter from the radiation, temperature swings, and dust storms that plague the planet. If the planet is anything like Earth or the Moon, it may have large underground lava tubes that could house shelters. Collapsed sections of lava tubes, called skylights, could provide access to these subterranean refuges.

Does this hole on Mars lead to a larger underground cavern?

This image was captured by the High-Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO). The pit is only a few meters across and is in the Arsia Mons region of Mars. Arsia Mons is one of the three dormant volcanos in the Tharsis Montes group of three volcanos.

This colourized image of the surface of Mars was created with data from the Mars Reconnaissance Orbiter. The line of three volcanoes is Tharsis Montes, with Olympus Mons to the northwest and Valles Marineris to the east. Arsia Mons is the southernmost volcano of the three that comprise Tharsis Montes. Image: NASA/JPL-Caltech/ Arizona State University

The Tharsis Region of Tharsis Bulge is a vast volcanic plain that’s thousands of kilometres across. It’s elevated compared to the rest of Mars and averages about 10km (33,000 ft) above the planet’s mean elevation. The region was volcanically active in the past, obviously, and features like the pit are a direct result of ancient volcanic activity.

Several pits in the Arsia Mons region may be collapsed skylights or openings into subterranean lava tubes. However, there is much uncertainty. An image of one of them shows an illuminated sidewall, which could indicate that it’s just a cylindrical pit.

These images of a pit near Arsia Mons were captured several years ago. The image on the left was captured first, and scientists wondered if it could lead to a lava tube or cave. Then, the image on the right, showing a side wall, was captured. The side wall could indicate that there’s no tube or cave. Image Credit: NASA/JPL/University of Arizona

The hole in the featured image could be only a pit or shaft and not an entrance to a cave or lava tube. They’re found on Hawaiian volcanos, where they’re called pit craters. They don’t connect to long caves or lava tubes. They’re the result of a collapse that happened much deeper underground.

These four sequential images show how pit craters form. As volcanos erupt and settle, cracks form. They slowly migrate upwards, and rocks above them start to fall into them. Eventually, the upward migrating crack reaches the surface, and the roof caves in. On Earth, plants will eventually colonize the crater. On Mars, they stay much the same as when they collapsed. Image Credit: US National Park Service.

In Hawaii, the pit craters range from 6 to 186 m (20 to 610 feet) deep and from 8 to 1140 m (26 to 3,740 feet) wide. The Arsia Mons pit in the leading image is only about 178 m (584 feet) deep.

We have a much better understanding of lava pits and tubes on the Moon than we do on Mars. We know some of them are thermally stable at about 17 C (63 F.) We also have better images of them, with intriguing glimpses of boulder-covered floors.

Spectacular high Sun view of the Mare Tranquillitatis pit crater revealing boulders on an otherwise smooth floor. The 100-meter pit may provide access to a lunar lava tube. Image Credit: By NASA/GSFC/Arizona State University – http://photojournal.jpl.nasa.gov/catalog/PIA13518, Public Domain, https://commons.wikimedia.org/w/index.php?curid=54853313

Lots of thinking is going into how to explore these lunar caves and lava tubes, including conceptual designs for robots that could explore them. Maybe on the Moon, astronauts could take shelter in inflatable habitats inside these tubes, where they’re protected from temperature swings, radiation, and micrometeorites.

But Mars is another question. There’s no reason that lava tubes shouldn’t exist on Mars. In fact, Mars’ gravity is much weaker than Earth’s, and that should allow for much larger tubes. Images of Mars show rilles, which are collapsed tubes. It seems likely that not all of these tubes have collapsed to form rilles.

One pit on the Martian volcano, Pavis Mons, is particularly intriguing. There’s some kind of void under the pit, but the nature of the pit is difficult to ascertain. Is it a lava tube? If it is, it dwarfs most tubes on Earth.

Martian lava tubes are still a mystery. Scientists have found plenty of morphological evidence suggesting that they’re plentiful. But in science, you can’t assume they’re there, even though it seems likely that they are. There’s no clear reason why they wouldn’t be. Could they one day provide shelter for astronauts? Maybe.

We need a robotic mission to explore them first.

The post What’s Under This Hole on the Surface of Mars? appeared first on Universe Today.

In 2018, astronomers detected an exoplanet around the star 40 Eridani. It’s about 16 light-years away in the constellation Eridanus. The discovery generated a wave of interest for a couple of reasons. Not only is it the closest Super-Earth around a star similar to our Sun, but the star system is the fictional home of Star Trek’s Vulcan science officer, Mr. Spock.

It’s always fun when a real science discovery lines up with science fiction.

Eridani’s other name is HD 26965, and it’s actually a triple-star system. Astronomers discovered the system’s lone planet, Eridani b, using the radial velocity method. Orbiting planets tug on their stars, and the star’s movement creates a change in its spectrum. Astronomical telescopes with spectrometers can detect the changes.

Jian Ge, an astronomy professor at the University of Florida, led the study that presented the discovery in 2018. At the time, Ge said in a press release, “The new planet is a ‘super-Earth’ orbiting the star HD 26965, which is only 16 light years from Earth, making it the closest super-Earth orbiting another Sun-like star. The planet is roughly twice the size of Earth and orbits its star with a 42-day period just inside the star’s optimal habitable zone.”

A super-Earth in the habitable zone around a Sun-similar star ‘only’ 16 light-years away is an intriguing discovery. Its link with a beloved Star Trek character gave the discovery wings, and word spread.

However, in the intervening years, follow-up observations have not confirmed Eridani b’s existence. A 2021 study suggested that the change in the star’s spectrum was a false positive. Now, a new study says that the exoplanet fondly named Vulcan does not exist.

The study is “The Death of Vulcan: NEID Reveals That the Planet Candidate Orbiting HD 26965 Is Stellar Activity.” It’s published in The Astronomical Journal, and the lead author is Abigail Burrows, an astronomer at Dartmouth College.

“We revisit the long-studied radial velocity (RV) target HD 26965 using recent observations from the NASA-NSF “NEID” precision Doppler facility,” Burrows and her co-authors write. After a deeper, line-by-line analysis of the radial velocity data, “… we demonstrate that the claimed 45-day signal previously identified as a planet candidate is most likely an activity-induced signal.”

Activity-induced signal means that the signal comes from the star’s activity, not from the external tug of an exoplanet.

Vulcan’s initial detection was based on data from the Dharma Planet Survey (DPS.) DPS monitored about 150 nearby Sun-like stars for changes in their spectra. Data from the Keck Telescope and the HARPS planet-finding spectrograph also contributed to the discovery.

When the planet was detected in 2018, the discoverers recommended caution. They presented the data as they collected it, along with their best interpretation. That’s standard in science, and they were careful in calling it a candidate planet. In their paper, they also discussed “the possibility that the RV signal is actually produced by stellar rotation modulated activity.” That activity could be sunspots, convection irregularities, or other things.

But in the end, they concluded that what they were seeing was likely a planet.

“By carefully examining the RV data in the active and quiet phases of the star, and after carefully considering all possible stellar activity sources, we concluded that the coherent signal seen from HD 26965 is most likely from a planet, with some RV noise contributed by stellar activity,” the authors wrote in the 2018 paper.

The rest of us were happy to agree because finding a super-Earth around a nearby Sun-like star is the kind of thing we hope to find.

“Men sometimes see exactly what they wish to see.”

-Spock of Vulcan

Sadly for Vulcan, the newest research shows that the stellar activity isn’t noise. It accounts for the entire signal.

The new results are based on NEID, the NN-explore Exoplanet Investigations with Doppler spectroscopy. It’s a high-resolution spectrometer attached to the WIYN (Wisconsin-Indiana-Yale-NOIRLab) telescope at Kitt Peak Observatory. The researchers used NEID to capture 63 spectra from Eridani over a six-month period.

NEID revealed a lot of information about the star, including things like contrast and radial velocity. Together, NEID data paints a more complete picture of the star and its activity. In this new work, Burrows and her co-researchers showed that all of this activity lines up with the star’s 42-day rotation period.

“All measurements show a strong signal at or near the 42-day stellar rotation period,” they write.

This figure from the study shows NEID data on the left. “All data show clear rotational modulation at or near the 42-day period,” the authors write. The right shows periodograms for the data, which show “clear power at the stellar rotation period of ?42 days.” Image Credit: Burrows et al. 2024

The authors write that their work “points toward a decaying starspot or plage” as the source of the signal. A plage is a bright spot on a star’s chromosphere. They used a variety of methods to reach this conclusion. “While each of these methods taken individually may not rule out a potential planetary signal at the same phase and period as the activity signal, collectively, our analyses show that an activity hypothesis is favoured over the specific planet claimed in Ma et al. (2018),” they conclude.

“When you eliminate the impossible, whatever remains, however improbable, must be the truth.”

Spock of Vulcan

The authors of the new paper didn’t set out to debunk Vulcan. Their paper is part of an effort to better understand the periodic and quasi-periodic spectral changes from Sun-like stars. Without a better understanding, annoying false positives will cloud our understanding of exoplanets, especially Earth-like ones around Sun-like stars. “To reach the precision necessary to detect temperate, Earth-mass extrasolar planets (exoplanets) around Sun-like stars using the radial velocity (RV) technique, the community must improve Doppler measurement precision significantly from the current state of the art,” they write.

“Detecting and characterizing these exo-Earths is vital for future spaceborne direct imaging missions, which will set the scientific priorities for the coming decade,” the authors explain.

The post Sorry Spock, But “Vulcan” Isn’t a Planet After All appeared first on Universe Today.