Astronomy

NASA's CADRE mini rovers have been test driven across the agency's "Mars Yard" and subjected to various other tests to confirm they are ready to launch to the moon.

The future European Space Agency mission could include an orbiting spacecraft as well as a lander, both of which would sample ocean material in Enceladus' plumes.

Can binary black holes, two black holes orbiting each other, influence their respective behaviors? This is what a recent study published in Science Advances hopes to address as a team of more than two dozen international researchers led by the Massachusetts Institute of Technology (MIT) investigated how a smaller black hole orbiting a supermassive black hole could alter the outbursts of the energy being emitted by the latter, essentially giving it “hiccups”. This study holds the potential to help astronomers better understand the behavior of binary black holes while producing new methods in finding more binary black holes throughout the cosmos.

“We thought we knew a lot about black holes, but this is telling us there are a lot more things they can do,” said Dr. Dheeraj “DJ” Pasham, who is a research scientist in MIT’s Kavli Institute for Astrophysics and Space Research and lead author of the study. “We think there will be many more systems like this, and we just need to take more data to find them.”

For the study, the researchers used a half dozen scientific instruments to obtain radio, ultraviolet, optical, and x-ray data on ASASSN-20qc, which is located approximately 260 megaparsecs (848,000,000 light-years) from Earth and was previously identified as a tidal disruption event (TDE) when first discovered in December 2020. The TDE responsible for astronomers first discovering ASASSN-20qc was caused by a star coming too close to the supermassive black hole and being slowly consumed over a four-month period. However, Dr. Pasham later looked over the data and found dips in energy output from the supermassive black hole occurring every 8.5 days throughout this four-month period.

Combining this data with computer models, the researchers confirmed the 8.5-day bursts of energy being emitted by supermassive black hole, which they hypothesize is caused by the smaller black orbiting around the larger one, with its own gravity influencing the gas and energy within the supermassive black hole’s disk. The researchers compare this phenomenon to an exoplanet transiting its parent star, resulting in a brief dip in starlight. These findings indicate that the disks of gas around black holes are far more chaotic than longstanding hypotheses have claimed.

“This is a different beast,” said Dr. Pasham. “It doesn’t fit anything that we know about these systems. We’re seeing evidence of objects going in and through the disk, at different angles, which challenges the traditional picture of a simple gaseous disk around black holes. We think there is a huge population of these systems out there.”

The supermassive black hole examined in this study exists at the center of its respective galaxy similar to other supermassive black holes found through the cosmos, with Sagittarius A* being the supermassive black hole at the center of our Milky Way Galaxy. However, finding another black hole orbiting the one examined in this study could help astronomers better understand the formation and evolution of supermassive black holes throughout the universe, with the study noting this research could lead to new methods in identifying binary black hole candidates, as well.

The reason astronomers are interested in learning more about binary black holes is the potential for them to teach us about gravitational waves, which were first proposed in the late 19th and early 20th century and gained traction in their existence and relevance through Albert Einstein’s general theory of relativity, as these gravitational waves have been hypothesized to create ripple in the fabric of spacetime. These gravitational waves are produced from the merging of binary black holes, with astronomers first detecting a black hole merger by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and corresponding results published in Physical Review Letters in 2016.

What new discoveries will astronomers make about binary black holes 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 Supermassive Black Hole with a Case of the Hiccups appeared first on Universe Today.

Universe Today has explored the importance of studying impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, planetary atmospheres, planetary geophysics, and cosmochemistry, and how this myriad of intricately linked scientific disciplines can assist us in better understanding our place in the cosmos and searching for life beyond Earth. Here, we will discuss the incredible research field of meteorites and how they help researchers better understand the history of both our solar system and the cosmos, including the benefits and challenges, finding life beyond Earth, and potential routes for upcoming students who wish to pursue studying meteorites. So, why is it so important to study meteorites?

Dr. Alex Ruzicka, who is a Professor in the Department of Geology at Portland State University, tells Universe Today, “They provide our best information about how the solar system formed and evolved. This includes planet formation. We also obtain information on astrophysics (stellar processes) through studies of pre-solar grains.”

There is often confusion regarding the differences between an asteroid, meteor, and meteorite, so it’s important to explain their respective differences to help better understand why scientists study meteorites and how they study them. An asteroid is a physical, orbiting planetary body that is primarily comprised of rock, but can sometimes be comprised of additional water ice, with most asteroids orbiting in the Main Asteroid Belt between Mars and Jupiter and the remaining orbiting as Trojan Asteroids in the orbit of Jupiter or in the Kuiper Belt with Pluto. A meteor is the visual phenomena that an asteroid produces as it burns up in a planet’s atmosphere, often seen as varying colors from the minerals within the asteroid when heated up. The pieces of the asteroid that survive the fiery entry and hit the ground are called meteorites, which scientists’ study to try and learn about the larger asteroid body it came from, and where that asteroid could have come from, as well. But what are some of the benefits and challenges of studying meteorites?

Dr. Ruzicka tells Universe Today, “Benefits: scientific knowledge, information on potential resources (e.g., metals, water) for humans to utilize, information on how to link meteorites and asteroids, which can provide information on space collision hazards for Earth. Challenges: compared to Earth rocks, we lack field evidence for their source bodies and parent bodies (how they relate to other rocks), we have to factor in the element of time that is longer for space rocks than for Earth rocks, and sometimes we are dealing with formation environments completely unlikely what we have on Earth. So, the challenges are big and many.”

According to NASA, more than 50,000 meteorites have been retrieved from all over the world, ranging from the deserts of Africa to the snowy plains of Antarctica. In terms of their origins, it is estimated that 99.8 percent of these meteorites have come from asteroids, with 0.1 percent coming from the Moon and 0.1 percent coming from Mars. The reason why we’ve found meteorites from the Moon and Mars is due to pieces of these planetary bodies being catapulted off their surfaces (or sub-surfaces) after experiencing large impacts of their own, and these pieces then travel through the Solar System for thousands, if not millions, of years before being caught in Earth’s gravity and the rest is history. Therefore, with meteorites originating from multiple locations throughout the Solar System, what can meteorites teach us about finding life beyond Earth?

Morgan Nunn Martinez, who was a PhD student at UC San Diego, and Dr. Alex Meshik seen photographing and measuring a meteorite specimen in Antarctica’s Miller Range during the 2013-2014 Antarctic Search for Meteorites (ANSMET) program field season. (Credit: NASA/JSC/ANSMET)

“That the ingredients for making life formed in space and were delivered to Earth,” Dr. Ruzicka tells Universe Today. “We know organic molecules formed in gas clouds, were incorporated in our solar system, and processed in asteroidal and cometary bodies under higher temperatures in the presence of water. These were then delivered to Earth which wouldn’t have been very hospitable in early times due to sterilizing impacts. We also know that there must have been a lot of planetary rock swapping early when impact rates were high. Life itself may have been transplanted to Earth from Mars.”

As it turns out, one of the most fascinating meteorites ever recovered did come from Mars, which was identified as ALH84001, as it was found in Allan Hills of Antarctica on December 27, 1984, during the 1984-85 field season where researchers from all over the world gather in Antarctica to search for meteorites using snowmobiles. Despite being collected in 1984, it wasn’t until 1996 that a team of scientists discovered what initially appeared to be evidence of microscopic bacteria fossils within the 1.93-kilogram (4.25-pound) meteorite.

ALH84001, which is one of the most famous meteorites ever recovered, helped catapult the field of astrobiology to new heights when scientists uncovered what initially appeared to be microscopic bacteria fossils within this meteorite, though those findings remain inconclusive to this day. (Credit: NASA)

This immediately made headlines across the globe, resulting in countless non-scientific claims that these microfossils were clear evidence of life on Mars. However, both the researchers of the initial study and the scientific community were quick to point out the unlikelihood that these features resulted from life based on other observations made about ALH84001. For example, while ALH84001 is estimated to be 4.5 billion years old, which is when Mars is hypothesized to have possessed liquid water on its surface, radiometric dating techniques revealed that ALH84001 was catapulted off Mars approximately 17 million years ago and landed on Earth approximately 13,000 years ago.

Microscopic image of ALH84001, which initially made headlines for potentially possessing microscopic bacteria fossils, though these finding remain inconclusive to this day. (Credit: NASA)

To this day, there has been no clear evidence that ALH84001 ever contained traces of life. Despite this, ALH84001 has nonetheless helped launch the field of astrobiology into new heights, with present-day scientists claiming this one meteorite was the reason they pursued their career path to find life beyond Earth. But what have been the most exciting aspects about meteorites that Dr. Ruzicka has studied throughout his career?

Dr. Ruzicka tells Universe Today, “A lot is interesting, what’s most exciting? That’s hard to say. I get satisfaction from taking clues left by the rocks to figure out or constrain the processes that formed them. I am engaged in a meteoritic version of CSI, we can call it MSI (for meteoritic scene investigation).”

Like many scientific fields, this “meteoritic version of CSI” requires individuals from a myriad of backgrounds and disciplines, including geology, physics, geochemistry, cosmochemistry, mineralogy, and artificial intelligence, just to name a few, with the aforementioned radiometric dating frequently used to estimate the ages of meteorites by measuring the radioactive isotopes within the sample. It is through this constant collaboration and innovation that scientists continue to unlock the secrets of meteorites with the goal of understanding their origins and compositions, along with how our Solar System, and life on Earth (and possibly elsewhere), came to be. Therefore, what advice can Dr. Ruzicka offer upcoming students who wish to pursue studying meteorites?

Dr. Ruzicka tells Universe Today, “Work hard and pursue your dreams. Find a rigorous program of study because it will come in handy.”

While meteorites are space rocks that crash land on Earth after traveling through the heavens for millions, and possibly billions, of years, these incredible geologic specimens are slowly helping scientists’ piece together the origins of the Solar System and beyond, and even how life might have come to be on our small, blue world, and possibly elsewhere. With a myriad of tools and instruments at their disposal, scientists from all over the world will continue to study meteorites in hopes of answering the universe’s toughest questions.

Dr. Ruzicka concludes by telling Universe Today, “Rocks from space are the best kinds of rocks to study. Way more cool than most rocks on Earth because they are in some ways more puzzling.”

How will meteorites help us better understand 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 Meteorites: Why study them? What can they teach us about finding life beyond Earth? appeared first on Universe Today.

Here is what the Earth looks like during a

On March 20th, China’s Queqiao-2 (“Magpie Bridge-2”) satellite launched from the Wenchang Space Launch Site LC-2 on the island of Hainan (in southern China) atop a Long March-8 Y3 carrier rocket. This mission is the second in a series of communications relay and radio astronomy satellites designed to support the fourth phase of the Chinese Lunar Exploration Program (Chang’e). On March 24th, after 119 hours in transit, the satellite reached the Moon and began a perilune braking maneuver at a distance of 440 km (~270 mi) from the lunar surface.

The maneuver lasted 19 minutes, after which the satellite entered lunar orbit, where it will soon relay communications from missions on the far side of the Moon around the South Pole region. This includes the Chang’e-4 lander and rover and will extend to the Chang’e-6 sample-return mission, which is scheduled to launch in May. It will also assist Chang’e-7 and -8 (scheduled for 2026 and 2028, respectively), consisting of an orbiter, rover, and lander mission, and a platform that will test technologies necessary for the construction of the International Lunar Research Station (ILRS).

A perilune braking maneuver is vital to establishing a lunar orbit and consists of a thruster firing as the spacecraft approaches the Moon. This reduces the spacecraft’s relative velocity to less than the lunar escape velocity (2.38 km/s; 1.74 mps) so that it can be captured by the Moon’s gravity. Two experimental satellites that will test navigation and communication technology (Tiandu-1 and -2), which accompanied the Queqiao-2 satellite to the Moon, also performed a perilune braking maneuver and entered lunar orbit on Monday.

These two satellites will remain in formation in an elliptical lunar orbit and will conduct communication and navigation tests, including laser ranging with the Moon and microwave ranging between satellites. According to the CNSA, Queqiao-2 will enter a 24-hour elliptical orbit around the Moon at a distance of 200 km (125 mi) at its closest point (perigee) and 100,000 km (62,000 mi) at its farthest point (apogee). Mission controllers will further alter Queqiao-2’s orbit and inclination to bring it into a “200 by 16,000-km, highly-elliptical ‘frozen’ orbit.”

Within this highly stable orbit, Queqiao-2 will have a direct line of sight with ground stations on Earth and the far side of the Moon and will conduct communication tests with Chang’e-4 and Chang’e-6 using its 4.2-m (13.8-ft) parabolic antenna. The mission could also support other countries in their lunar exploration efforts, many of whom are also interested in scouting the Moon’s far side and southern polar region. The satellite also carries scientific instruments, including extreme ultraviolet cameras, array-neutral atom imagers, and lunar orbit Very Long Baseline Interferometry (VLBI) test subsystems.

According to state-owned media company CCTV, the CNSA chose the Queqiao-2 satellite’s present orbit for a multitude of reasons:

“Experts told me that this is an ideal location on the Moon to observe the separation of the Queqiao-2 star arrow, and it also has a deep connection with China’s lunar exploration project. This is the Moon’s rich maria region… Fifteen years ago, on March 1, 2009, it was here that the Chang’e-1 probe of China’s lunar exploration project completed a controlled collision with the Moon… The location of the Sea of Abundance on the moon is also very eye-catching. The next time the moon is full, you look up at the moon and find this dark black patch in the southeast of the moon. This is the Sea of Abundance!”

Visualization of the ILRS from the CNSA Guide to Partnership (June 2021). Credit: CNSA

The satellite will support China’s upcoming Chang’e-6 mission, China’s second attempt to return lunar samples to Earth. Mission controllers will adjust its orbit into a 12-hour period to support the Chang’e-7 and -8 missions. These missions aim to map the terrain and scout resources (particularly water ice) around the South Pole-Aitken Basin. These missions will ultimately support the creation of the ILRS, a joint project between CNSA and Roscomos to create a lunar base that will enable research and development on the Moon.

This program is intended to rival NASA’s Artemis Program, which will send astronauts on a circumlunar flight next year – the Artemis II mission. The program will culminate in 2026 with the first crewed mission to the lunar surface (Artemis III) in over 50 years. NASA also plans to deploy the core elements of the Lunar Gateway next year, an orbital habitat that will facilitate the deployment of the Artemis Base Camp. Along with its international and commercial partners, these elements will support the creation of “a sustained program of lunar exploration and development.”

Further Reading: CGTN

The post China's Relay Satellite is in Lunar Orbit appeared first on Universe Today.

Some stars are so massive and so energetic that they’re a million times brighter than the Sun. This type of star dominated the early Universe, playing a key role in its development and evolution. The first of its kind are all gone now, but the modern Universe still forms stars of this type.

These hot, blue stars emit powerful ultraviolet energy that the Hubble can detect from its perch in Low-Earth Orbit.

In December 2023, astronomers completed a three-year survey of these hot stars. It’s one of the Hubble’s largest and most ambitious surveys. It’s called ULLYSES (Ultraviolet Legacy Library of Young Stars as Essential Standards), and in it, astronomers gathered detailed information on almost 500 stars.

UV emissions from hot young stars provide a window into some of the processes inside these stars. UV can’t be observed from Earth because the ozone layer blocks it. That’s one of the reasons the Hubble was built. From its perch, it can gather high-resolution UV images. That’s the impetus for ULLYSES.

The survey doesn’t contain images of all the stars. Instead, the Hubble gathered spectra from 220 stars and combined them with Hubble archival data on 275 additional stars. Powerful ground-based telescopes also made a contribution, though not in UV. The result is a very rich dataset consisting of detailed spectra from both hot, bright, massive stars and from cool, dim, low-mass stars.

“I believe the ULLYSES project will be transformative, impacting overall astrophysics – from exoplanets to the effects of massive stars on galaxy evolution, to understanding the earliest stages of the evolving universe,” said Julia Roman-Duval, Implementation Team Lead for ULLYSES at the Space Telescope Science Institute (STScI) in Baltimore, Maryland. “Aside from the specific goals of the program, the stellar data can also be used in fields of astrophysics in ways we can’t yet imagine.”

The ULYSSES spectra collected by Hubble can reveal the presence of chemical elements in the stars. Image Credit: Hubble/ STScI/ULYSSES

Spectra can tell astronomers more than just the metallicity of the stars. They can also reveal the powerful stellar winds coming from the hot blue stars.

Massive blue stars have powerful winds that shape their surroundings. The Hubble spectra can tell which way the winds travel and how fast they travel. The star represented by the teal line has slower winds than the star shown by the purple line. Image Credit: Hubble/ STScI/ULYSSES

Spectra also reveal the metallicity of stars. Stars with lower metallicity are typically older than stars with higher metallicity. A critical part of stellar metallicity concerns the iron content. Astronomers use iron content and its ratio with hydrogen to date stars in relation to our own Sun’s iron and hydrogen ratio.

These spectra show the iron content for two stars. In this image, the star represented by the purple line has less iron, indicating that it’s older than the other star. Iron content affects a star’s lifetime and the strength of its winds. Image Credit: Hubble/ STScI/ULYSSES

In ULYSSES, Hubble targeted hot blue stars in nearby galaxies with low metallicity, the type that would’ve existed in the early Universe. At that point in the Universe’s life, they would’ve contained nothing heavier than hydrogen and helium. This type of galaxy was common in the very early universe. Only once these hot young stars died and spread the elements they created inside themselves would the heavier elements needed for rocky planets, water, and even life be available. “ULLYSES observations are a stepping stone to understanding those first stars and their winds in the Universe and how they impact the evolution of their young host galaxy,” said Roman-Duval.

ULLYSES also observed stellar counterparts to the massive, hot stars: cool, red, low-mass, and dim stars. While the more massive stars form quickly, burn bright, and die soon, these ones are the opposite. They take longer to form, are dimmer, and last much longer. But they still emit winds and energy that shape their surroundings. They’re called T-Tauri stars, stars so young they’re still growing.

As part of the three-year ULYSSES survey, the Hubble also observed cool, dim, low-mass stars like the one in this artist’s illustration, which are still growing by accreting material from their disks. Image Credit: Robert O’Connell (UVA), SOC-WFC3, ESO

Despite their lower masses, these stars emit powerful radiation. During their formation, they’re known to unleash powerful blasts of both UV and X-ray radiation.

There are outstanding questions about T-Tauri stars and how they behave. Some of their processes are obscured. But the Hubble spectra from ULYSSES can provide some answers. They can reveal how much energy T-Tauri stars release as they grow and how powerful their winds are. Their powerful winds can alter their protoplanetary disks, blowing material away and making it unavailable for planet formation. In some cases, the powerful energy from these stars could eliminate the habitability of any planets forming around them.

The ULYSSES data is not meant to answer any specific question. Rather, it’s a massive database of detailed spectra that researchers can query to serve future research. The overarching goal is to provide an in-depth database of spectra from young stars that are in the first 10 million years of their lives.

“More fully understanding the formation and lives of young stars has connections to many other areas in astronomy, including galaxy formation and evolution, the mechanics and mass loss of supernovas, how stars’ environments impact planet formation, and how their emissions may play a role in the makeup of the interstellar medium, the gas and dust between stars in a galaxy,” the ULYSSES website explains. 

ULYSSES is an observing program designed by the research community for the research community. By extension, it also serves those of us who like to follow along as researchers discover new things about the Universe.

“ULLYSES was originally conceived as an observing program utilizing Hubble’s sensitive spectrographs. However, the program was tremendously enhanced by community-led coordinated and ancillary observations with other ground- and space-based observatories,” said Roman-Duval. “Such broad coverage allows astronomers to investigate the lives of stars in unprecedented detail and paint a more comprehensive picture of the properties of these stars and how they impact their environment.”

The post The Hubble Aims Its Powerful Ultraviolet Eye at Super-Hot Stars appeared first on Universe Today.