Astronomy

Video: 00:14:09

The Copernicus Sentinel-2C satellite lifted off on 5 September at 03:50 CEST (4 September 22:50 local time) aboard the last Vega rocket, flight VV24, from Europe’s Spaceport in French Guiana.

Sentinel-2C will continue the legacy of delivering high-resolution data that are essential to Copernicus – the Earth observation component of the EU Space Programme. Developed, built and operated by ESA, the Copernicus Sentinel-2 mission provides high-resolution optical imagery for a wide range of applications including land, water and atmospheric monitoring.

Sentinel-2C was the last liftoff for the Vega rocket – after 12 years of service this was the final flight, the original Vega is being retired to make way for an upgraded Vega-C.

The third Copernicus Sentinel-2 satellite launched today aboard the final Vega rocket from Europe’s Spaceport in French Guiana. Sentinel-2C will continue providing high-resolution data that is essential to Copernicus – Europe’s world leading Earth observation programme.

Sentinel-2C launched into orbit on 5 September at 03:50 CEST (4 September 22:50 local time) and separated from the Vega rocket at approximately 04:48 CEST.

The discovery of dark oxygen at an abyssal plain on the ocean floor generated a lot of interest. Could this oxygen source support life in the ocean depths? And if it can, what does that mean for places like Enceladus and Europa?

What does it mean for our notion of habitability?

Oxygen is key to complex life on Earth, where photosynthesis generates most of it. The Great Oxygenation Event (GOE), which occurred about 2.5 billion years ago, led to the development of complex life and changed Earth forever. In the GOE, the oxygen was generated by living things.

Our notions of habitability rest on a planet’s proximity to its star, and part of that is because we know that the Sun drives life on Earth by allowing water to remain liquid and providing energy for organisms. But dark oxygen on the ocean floor is strictly abiotic, meaning no life was involved in its production and sunlight isn’t involved.

In recent years, we’ve learned that other Solar System bodies, far beyond the circumstellar habitable zone, could be habitable. The icy ocean moons of Europa, Ganymede, and Enceladus may harbour vast, warm oceans under frigid caps of ice. If Earth produces dark oxygen on its ocean floors, maybe these worlds do, too.

New research examines Earth’s dark oxygen and what it might mean for biology here and on other worlds. It’s titled “Dwellers in the Deep: Biological Consequences of Dark Oxygen.” The lead author is Manasvi Lingam from the Department of Aerospace, Physics, and Space Sciences at the Florida Institute of Technology. The research is awaiting peer review.

Dark oxygen comes from metal deposits called polymetallic nodules. These nodules generate enough electricity to drive electrolysis, which splits water molecules apart and releases oxygen. The amount of oxygen is not large, but it’s there, and it’s measurable.

By Hannes Grobe/AWI – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=104756773

“The striking recent putative detection of “dark oxygen” (dark O2) sources on the abyssal ocean floor in the Pacific at ~4 km depth raises the intriguing scenario that complex (i.e., animal-like) life could exist in underwater environments sans oxygenic photosynthesis,” the authors write.

The amount of dark oxygen in the ocean is small, which limits the size of organisms. Organisms use oxygen through diffusion and circulation, and oxygen levels place restraints on the sizes of both types.

Diffusion is a simple process in which nutrients, waste, and water diffuse through a few layers of tissue. Circulation is more complex and involves a heart pumping fluid to an organism’s cells, delivering nutrients and removing waste. The amount of environmental oxygen places limits on the sizes of both types of organisms.

“The maximal sizes attainable by idealized unicellular or multicellular organisms (i.e., constrained by internal or external diffusion processes) for the estimated concentrations of dark O2 may be ~ 0.1–1 mm.,” the authors write.

For animals with circulation systems, the upper size boundary is higher but still limited.

“In contrast, the upper-size bounds of organisms with internal circulation systems for the distribution of oxygen could range between ~ 0.1 cm to ~ 10 cm, with the latter threshold falling under the umbrella of “megafauna,” the researchers explain.

Aside from the size of individual organisms, there’s the overall biomass density. In an optimistic scenario, the researchers report that biomass density could exceed the reported density. “Under optimistic circumstances, the biomass densities might reach as high as ~ 3–30 g m?2, in principle exceeding the reported macrofaunal densities at depths of ~ 4 km in global deep-sea surveys,” the authors write.

This work inspires a multitude of questions. We know that microorganisms in groundwater use dark oxygen. What types of microorganisms have adapted to these ocean dark oxygen environments? What about their metabolism allows them to live there? Have larger organisms adapted to these environments? Did organisms in these environments play a role in the evolution of life on Earth?

The discovery also compels us to consider its implications for astrobiology. On Earth, abyssal deep sea plains represent about 70% of the ocean floor, making them the largest ecosystem on Earth. Even with a low biomass density, the region is significant.

This cross-section of an oceanic basin shows the relationship of the abyssal plain to a continental rise and an oceanic trench. On Earth, 70% of the sea floor is abyssal plain, making it the largest ecosystem on Earth. Image Credit: By Chris_huh – Own work, Public Domain, https://commons.wikimedia.org/w/index.php?curid=1812130

When considering the habitability of the ocean moons, we’re at a disadvantage. We don’t know what the sea floors look like on these bodies. In fact, despite all of the enthusiasm, we don’t even know for certain if these moons have oceans. We also don’t know if the oceans, if any of them exist, can produce polymetallic nodules that generate dark oxygen.

However, there are other ways dark oxygen can be generated without nodules. One of them is radiolysis.

Radiolysis is the breaking apart of molecules by ionizing radiation, and there’s plenty of that in the vicinity of Jupiter. Spacecraft have spotted O2 trapped in bubbles on Europa, Ganymede, and Callisto. Does that mean it’s available for life that might exist in their hypothetical oceans?

Radiation from Jupiter can break apart molecules on Europa’s surface. This can free oxygen, which could percolate in brines through the surface into the ocean under the ice. Credit: NASA/JPL-Caltech

“The production of oxidants on the surface and their delivery to the ocean can effectively input O2 to the latter even sans photosynthesis,” the authors explain. Europa’s icy shell isn’t all solid ice. Scientists think that briny liquid can percolate through the ice, and that could potentially deliver surface dark oxygen to the ocean.

There’s a third pathway for dark oxygen called microbial dismutation. Though it’s biotic, it doesn’t rely on photosynthesis. It could be an overlooked source of oxygen.

The evidence we have so far says that worlds like Earth are extremely rare, while environments like Europa could be widespread. “To round off our preliminary venture into this eclectic subject, we reiterate our
prefatory statement that marine habitable settings implausible for photosynthesis, especially on icy worlds with subsurface oceans, are likely widespread in the Universe,” the authors write in their conclusion.

“Therefore, if dark oxygen production is feasible and commonplace on this class of worlds – whether via seawater electrolysis or the prior two routes – then our analysis may broadly encapsulate the profound consequences of dark oxygen for the prevalence of abiogenesis, complex multicellularity, and perhaps even technological intelligence in the Cosmos,” the authors explain.

The fact that we’ve only now discovered dark oxygen on the ocean floor should make us all pause. We’re discovering things about nature that could be critical in the search for life and habitable worlds. If we can confirm that the so-called ocean moons really do have oceans and that dark oxygen is either produced in or transported to those oceans, then we have to adapt our thinking about habitability. Proximity to a star may not be critical, which would simultaneously broaden our understanding while deepening the mystery of life in the cosmos.

That’s the intriguing part of science. It’s equal part mysteries and answers.

The post Dark Oxygen Could Change Our Understanding of Habitability appeared first on Universe Today.

Chinese astronauts aboard the Tiangong space station are studying microbes, to help determine if some of Earth's early lifeforms can handle a simulated cosmic environment.

The Hubble Space Telescope has imaged one of Andromeda's dwarf galaxies. It's named Pegasus.

The Celestron Origin is an easy-to-use smart telescope that will have you producing stunning pictures of deep sky objects in minutes.

With all of humanity’s telescopic eyes on the sky, it’s rare for an asteroid to take us by surprise. But that’s what happened this morning in the sky over the Philippines. Only hours after it was detected, it burned up in a bright flash above the island of Luzon.

NASA’s Catalina Sky Survey detected the small asteroid, now named 2024 RW1, only hours before it reached Earth’s atmosphere. It was only about one meter in diameter and posed no threat. Even though reports say it “struck the Earth,” in reality, it only struck the atmosphere, where objects that small burn up.

A video captured from the northern tip of the Philippines shows a flashing fireball partly obscured by clouds. The asteroid briefly created a tail, which disappeared quickly.

??????? ?? ?????, ???????? ???? ???! ??

Here's a clear shot of the much-awaited small asteroid 2024 RW1 (#CAQTDL2) burning bright into a greenish 'fireball' over Lal-lo, Cagayan around 12:39 AM PhST, 05 September 2024. Did you see it too? ?

?… pic.twitter.com/B3oAm6nNdD

— ScienceKonek (@sciencekonek) September 4, 2024

This is only the ninth time that we’ve detected an asteroid before it reached Earth, though the European Space Agency says that a one-meter asteroid hits the Earth every two weeks.

Being taken by surprise by an asteroid is an unusual feeling. But though it was a surprise, it was detected before it reached us. We can take comfort that our automated sky surveys detected such a small object. If it was large enough to cause any amount of damage, it would’ve been brighter and we’d have detected it much sooner.

Though this one was no danger, that’s not always the case. In 2013, the 18-ton near-Earth asteroid called the Chelyabinsk meteor exploded over the Russian city. It created extensive ground damage and caused almost 1500 people to seek medical assistance, though nobody was killed.

A meteorite flashes across the sky over Chelyabinsk, Russia, taken from a dashboard camera.

Earth has suffered much more catastrophic impacts than that throughout its history, and that spectre haunts our civilization. The Chicxululb impact caused a mass extinction and ended the dinosaurs. The Vredefort Crater in South Africa was excavated two billion years ago by an impactor between 10 to 15 km in diameter.

But it’s not just an asteroid’s size that’s the problem. They strike Earth with great velocity. The ESA says that 2024 RW1 was travelling at 17.6 kilometres per second, or 63,360 kilometres per hour, which is the average speed for these objects.

Both NASA and the ESA actively search for and catalogue the asteroid population. NASA also invites experts to take part in regular mock exercises. In these exercises, teams of people are fed regular fabricated updates on the approach of a dangerous asteroid and asked to take whatever actions they see fit.

2024 RW1 was no threat. In fact, it’s a beautiful, natural spectacle.

But it’s also a reminder that Earth isn’t isolated from the cosmos, though in day-to-day life, it can seem like it is.

The post A Surprise Asteroid Lit Up the Sky Over the Philippines appeared first on Universe Today.

Blue Origin's droneship, named "Jacklyn," arrived at Florida's Port Canaveral ahead of the inaugural launch of the company's huge New Glenn rocket next month.

A band that measures the acidity of sweat could flag if athletes or manual workers are overexerting themselves

A band that measures the acidity of sweat could flag if athletes or manual workers are overexerting themselves

It's a little on the expensive side, but this Lego space station playset packs in multiple ways to play.

Boeing's Starliner spacecraft will fly back to Earth for a landing on Sept. 7, but without its crew. Its two astronauts will ride home on SpaceX Crew Dragon in February 2025.

Summer has been brutally hot in the Southwest, toppling records set just last year, and the heat isn’t over yet

NASA's Europa Clipper mission is on track for an October launch following tests confirming the spacecraft can handle the harsh conditions around Jupiter's intriguing moon.

Between Low Earth Orbit (LEO) and the Moon, there is a region of space measuring 384,400 km (238,855 mi) wide known as Cislunar space. In the coming decades, multiple space agencies will send missions to this region to support the development of infrastructure that will lead to a permanent human presence on the Moon. This includes orbital and surface habitats, landing pads, surface vehicles, technologies for in-situ resource utilization (ISRU), and other elements that will enable the long-term exploration and development of the lunar surface.

For all parties concerned, Cislunar space holds immense potential in terms of scientific, commercial, and military applications. The vastly increased level of activity on and around the Moon makes space domain awareness (SDA) – knowledge of all operations within a region of space – paramount. It is also necessary to ensure the continued success and utilization of the covered region. In a recent paper, a team of aerospace engineers considered the missions planned for the coming decades and evaluated the state and shortcomings of their space domain awareness.

The study was led by Brian Baker-McEvilly, an aerospace engineering graduate student at Embry-Riddle Aeronautical University (ERAU). He was joined by David Canales, an assistant professor of aerospace engineering at ERAU, and Surabhi Bhadauria and Carolin Frueh, a Ph.D. candidate and an assistant professor at Purdue University’s School of Aeronautics and Astronautics. The paper that describes their findings recently appeared online and is being considered for publication by

NASA’s Lunar Surface Sustainability Concept, which includes the Artemis Program. Credit: NASA Space Domain Awareness

Also known as “space situational awareness,” SDA is essential to operations in space. As Baker-McEvilly explained to Universe Today via email:

“SDA is essentially the concept of having comprehensive knowledge of all objects in a specific region without necessarily having direct communication with those objects. It is essential for the safety and security of spacecraft as it provides valuable information on objects in their vicinity that have the potential to influence the outcome of their mission. Some general examples of the importance of SDA are the information helps avoid collisions, ensures accurate tracking information, and provides knowledge on other space activities.”

As NASA states, the goal of the Artemis Program is to “create a sustained program of lunar exploration and development.” Similarly, China, Roscosmos, and the ESA hope to create lunar habitats and related infrastructure to allow for a permanent human presence on the Moon. A key element of these programs is to create habitats in the Moon’s southern polar region (the South Pole-Aitken Basin). These activities will require considerable support in the form of payload deliveries, and the export of lunar resources will similarly require regular missions to and from the lunar surface. Given this level of activity, SDA will be more vital than ever.

Many Plans

As per the Artemis Program, NASA intends to conduct the first circumlunar flight with a crewed Orion spacecraft (Artemis II) no sooner than September 2025. This will be followed by Artemis III in September 2026, the first crewed mission to the lunar surface since Apollo 17 in 1972. This will be accomplished by launching a crewed Orion spacecraft using the Space Launch System (SLS) to lunar orbit. The Human Landing System (HLS) provided by SpaceX – the Starship HLS – will launch separately, refuel in orbit, and then rendezvous with the Orion spacecraft around the Moon.

Once the transfer of two astronauts to the HLS is complete, they will fly down to the lunar surface and spend about 30 days conducting experiments and retrieving samples. Beyond Artemis III, NASA will begin to focus on deploying the core elements of the Lunar Gateway, which will launch in 2027 aboard a Falcon Heavy rocket. The Artemis IV mission will follow in September 2028 and will see a crew of four transfer from an Orion spacecraft to the Lunar Gateway for the first time. After that, NASA intends to send a mission a year to the lunar surface and deploy the elements of the Artemis Base Camp. These will include the following:

• Lunar Terrain Vehicle (LTV): a rover that will transport crew around the landing zone
• Habitability Mobility Platform (HMP): a pressurized rover that will enable crews to take trips across the lunar surface lasting up to 45 days
• Lunar Foundation Surface Habitat (LFSH): a stationary habitat that will house as many as four crew members on shorter surface stays

Credit: NASA

In addition, China and Russia have announced their intentions to create the International Lunar Research Station (ILRS), which would rival NASA’s proposed infrastructure. The proposed timeline involves three phases. The Reconnaissance phase will conclude with the Chang’e-7 mission (launching in 2026), which will continue to explore the lunar surface around the South Pole-Aitken Basin to scout for resources and assess possible sites for a future habitat. Phase Two, Construction, will occur between 2026 and 2035 and will see the deployment of the elements that make up the ILRS.

Meanwhile, the European Space Agency (ESA) has made multiple studies and proposals for an international lunar base that would serve the same purpose as the International Space Station (ISS). Previous proposals include the ESA’s Moon Village, which consisted of a facility extending beneath the surface and a dome covered in regolith that would allow access to the surface. This was followed in 2019 with the ESA and international architecture firm Skidmore, Owings & Merrill (SOM) proposing a series of semi-inflatable modules deployed along the rim of a lunar crater.

The latest concept was another collaborative effort between the ESA and the international architecture firm Hassel. Their proposal, the Lunar Habitat Master Plan, consists of a modular, scalable habitat system that can accommodate a settlement of up to 144 people. As part of their study, Baker-McEvilly and his colleagues reviewed these plans and identified two major trends. As he related.

“Two key trends emerge when looking over these missions; the importance of establishing sustainable operations and the strategic value of the Lunar South Pole. Many future missions have objectives to test new technologies that support sustainable operations on the Moon, such as water harvesting methods from Lunar regolith for astronauts, efficient landing methods to support constant movement to and from the surface of the Moon, or utilizing orbital trajectories that require little fuel to remain within.

“The Lunar South Pole is a key piece of Cislunar space as it is an efficient geographic location for these sustainable operations. The South Pole possesses permanently shadowed craters that contain concentrations of water within the regolith. Also, the near-rectilinear halo orbit (NRHO) that will house Gateway spends the majority of its trajectory within line of sight of the South Pole and requires very little fuel to maintain under outside perturbations.”

Getting There

Another key aspect of their study was the dynamics of the Cislunar environment and the challenges of sending spacecraft from the Earth to the Moon. These challenges are well-known, thanks to decades of sending robotic missions there, not to mention crewed missions in the form of the Apollo Program. In the coming decades, this region is expected to become rather crowded with satellites, spacecraft, the Lunar Gateway, and other orbital facilities. Things are made more complicated by the fact that any object in Cislunar space will have to contend with the Three-Body Problem. Said Baker-McEvilly:

“[The] dynamics of the Cislunar realm become challenging due to the introduction of the third body in the orbital mechanics problem. As of now, the three-body problem does not have a closed-form solution, and a spacecraft under the influence of both the Earth and Moon no longer moves in the traditional two-body Keplerian sense that many are familiar with. This causes many of the traditional methods in astrodynamics to break down, thus requiring new models and methods to solve problems.”

In the end, they identified a few families of orbits that highlight the unique geometry of periodic trajectories in the Three-Body Problem, as well as orbits that may have strategic use in the future. However, as Baker-McEvilly added, these trajectories are not all-encompassing, and many more exist that have been well-documented.

Shortcomings

Upon reviewing the existing and anticipated missions that will be going to the Moon in the coming decades, Baker-McEvilly and his colleagues identified several shortcomings where SDA was concerned. They also provide recommendations on how these can be addressed. As he indicated:

“The SDA methods used to monitor objects about the Earth that rely on Earth-based sensors do not directly translate to being able to view objects in Cislunar space. The significant distance an Earth-based sensor must cover to reach areas of Cislunar space is outside the capabilities of many sensors, especially radar systems. For the sensors capable of spanning this distance, such as the Deep Space Network, they are often already overtasked and are too valuable to only be dedicated to SDA.

“Another shortcoming is the challenging illumination conditions optical sensors must overcome to view objects deep in Cislunar space. Issues such as the Moon physically blocking view of missions on the far-side, or the light reflected off the Moon washing out light reflected off a spacecraft hinders the capabilities of optical sensors. As a result, there are important regions of Cislunar space that are not always in view by current sensor networks.”

Artist’s representation of Cislunar space, with distances included. Credit: Paul Spudis.

As Baker-McEvilly noted, researchers are investigating many approaches to address the gap in Cislunar SDA capabilities. Some possibilities include placing sensors on the Moon, improving the network of Earth-based sensors, or implementing constellations of satellite-based sensors throughout Cislunar space. In his opinion, some combination of these solutions is best suited to solving the SDA gap. He also hopes their study provides researchers, students, and those interested in lunar exploration with a foundation on the current state of Cislunar space and the issues it faces.

“The key issues highlighted across the analysis in Cislunar exploration and SDA may incline some readers to pay more attention to these points and come up with their own work that contributes to the solution or prevent similar failures from repeating themselves,” he said.

Further Reading: arXiv

The post A Review of Humanity’s Planned Expansion Between the Earth and the Moon appeared first on Universe Today.

Comet C/2023 A3, also known as Tsuchinshan–ATLAS, is expected to grace our skies from mid-October. Abigail Beall is hoping for a dazzling display

Comet C/2023 A3, also known as Tsuchinshan–ATLAS, is expected to grace our skies from mid-October. Abigail Beall is hoping for a dazzling display

The deeply researched podcast series Tested tells the stories of Namibian sprinter Christine Mboma and Kenya’s Maximila Imali, and how their early successes made their womanhood suspect to some

The deeply researched podcast series Tested tells the stories of Namibian sprinter Christine Mboma and Kenya’s Maximila Imali, and how their early successes made their womanhood suspect to some