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Springtime Leo walks high in the south, springtime Hydra snakes a quarter of the way around the celestial sphere, and the bright Moon aligns with Spica.

The post This Week's Sky at a Glance, April 19 – 28 appeared first on Sky & Telescope.

Image: Earth from Space: The Mekong Delta

Image: Photo of total solar eclipse

Last year’s marine heatwaves saw an unprecedented decline in the growth of phytoplankton and algae, which many animals in the oceans depend on for food

Last year’s marine heatwaves saw an unprecedented decline in the growth of phytoplankton and algae, which many animals in the oceans depend on for food

Both a special diet that excludes “FODMAP” compounds and a low-carb high-fibre diet were effective

Both a special diet that excludes “FODMAP” compounds and a low-carb high-fibre diet were effective

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AI for Earth: How NASA’s Artificial Intelligence and Open Science Efforts Combat Climate Change Lights brighten the night sky in this image of Europe, including Poland, taken from the International Space Station. NASA

As extreme weather events increase around the world due to climate change, the need for further research into our warming planet has increased as well. For NASA, climate research involves not only conducting studies of these events, but also empowering outside researchers to do the same. The artificial intelligence (AI) efforts spearheaded by the agency offer a powerful tool to accomplish these goals.

In 2023, NASA teamed up with IBM Research to create an AI geospatial foundation model. Trained on vast amounts of NASA’s widely used Harmonized Landsat and Sentinel-2 (HLS) data, the model provides a base for a variety of AI-powered studies to tackle environmental challenges. In keeping with open science principles, the model is freely available for anyone to access.

Foundation models serve as a baseline from which scientists can develop a diverse set of applications, enabling powerful and efficient solutions. “Foundation models only know what things are represented in the data,” explained Manil Maskey, the data science lead at NASA’s Office of the Chief Science Data Officer (OCSDO). “It’s like a Swiss Army Knife—it can be used for multiple different things.”

Once a foundation model is created, it can be trained on a small amount of data to perform a specific task. To date, the Interagency Implementation and Advanced Concept Team (IMPACT) along with collaborators have demonstrated the geospatial foundation model’s capabilities by fine-tuning it to detect burn scars, to delineate flood water, and to classify crop and other land use categories.

Rectangular ponds for shrimp farming line the coast of northern Peru in this image captured on March 14, 2024 by the OLI-2 (Operational Land Imager-2) on Landsat 9. NASA Earth Observatory / Lauren Dauphin

Because of the computational resources required to create the initial foundation model, a partnership was necessary for success. In this case, NASA brought the data and scientific knowledge, while IBM brought the computing power and AI algorithm optimization expertise. The team’s shared commitment to making their research accessible through open science principles ensures that their model can be useful to as many researchers as possible.

“To build a foundation model at scale, we realized early on that it’s not feasible for one institution to build it,” Maskey said. “Everything we have done on our foundation models has been open to the public, all the way from pre-training data, code, best practices, model weights, fine-tuning training data, and publications. There’s transparency, so researchers can trace why certain things were used in terms of data or model architecture.”

Following on from the success of their geospatial foundation model, NASA and IBM Research are continuing their partnership to create a new, similar model for weather and climate studies. They are collaborating with Oak Ridge National Laboratory (ORNL), NVIDIA, and several universities to bring this model to life.

This time, the main dataset will be the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), a huge collection of atmospheric reanalysis data that spans from 1980 to the present day. Like the geospatial foundation model, the weather and climate model is being developed with an open science approach, and will be available to the public in the near future.

Covering all aspects of Earth science would take several foundation models trained on different types of datasets. However, Maskey believes those future models might someday be combined into one comprehensive model, leading to a “digital twin” of the Earth that would provide unparalleled analysis and predictions for all kinds of climate and environmental events.

Whatever innovations the future holds, NASA and IBM’s geospatial and climate foundation models will enable leaps in Earth science like never before. Though powerful AI tools will enhance researchers’ work, the team’s dedication to open science supercharges the possibilities for discovery by allowing anyone to put those tools into practice and pave the way for groundbreaking research to help better care for the planet.

For more information about open science at NASA, visit:
https://science.nasa.gov/open-science/

By Lauren Leese
Web Content Strategist for the Office of the Chief Science Data Officer

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Back in the 1960s and 1970s, Apollo astronauts set up a collection of lunar seismometers to detect possible Moon quakes. These instruments monitored lunar activity for eight years and gave planetary scientists an indirect glimpse into the Moon’s interior. Now, researchers are developing new methods for lunar quake detection techniques and technologies. If all goes well, the Artemis astronauts will deploy them when they return to the Moon.

Fiber optic cable is the heart of a seismology network to be deployed on the Moon by future Artemis astronauts.

The new approach, called distributed acoustic sensing (DAS), is the brainchild of CalTech geophysics professor Zhongwen Zhan. It sends laser beams through a fiber optic cable buried just below the surface. Instruments at either end measure how the laser light changes during the shake-induced tremors. Basically Zhan’s plan turns the cable into a sequence of hundreds of individual seismometers. That gives precise information about the strength and timing of the tremors. Amazingly, a 100-kilometer fiber optic cable would function as the equivalent of 10,000 seismometers. This cuts down on the number of individual seismic instruments astronauts would have to deploy. It probably also affords some cost savings as well.

A seismometer station deployed on the Moon during the Apollo 15 mission. Courtesy NASA. DAS and Apollo on the Moon

Compare DAS the Apollo mission seismometer data and it becomes obvious very quickly that DAS is a vast improvement. In the Apollo days, the small collection of instruments left behind on the Moon provided information that was “noisy”. Essentially, when the seismic waves traveled through different parts of the lunar structure, they got scattered. This was particularly true when they encountered the dusty surface layer. The “noise” basically muddied up the signals.

The layout for the Apollo Lunar Seismic Profiling Experiment for the Apollo 17 mission. Courtesy Nunn, et al. What DAS Does to Detect Quakes on the Moon

The DAS system stations laser emitters and data collectors at each end of a fiber optic cable. This allows for multiple widely spaced installations that measure light as it transits the network. The cable consists of glass strands, and each strand contains tiny imperfections. That sounds bad, but each imperfection provides a useful “waypoint” that reflects a little bit of the light back to the source. That information gets recorded as part of a larger data set. Setting up such a system of telecommunications cables over a large area provides millions of waypoints that scientists can use to measure seismic movements on Earth.

A recent study led by CalTech postdoctoral researcher Qiushi Zhai deployed this type of DAS-enabled fiber optic cable system in Antarctica. The conditions mimic some of the environmental challenges of a lunar deployment—it’s freezing cold, very dry, and far removed from human activities. The sensors measured the small movements of caused by ice cracking and moving around. Those types of signals are perfect analogs to lunar quakes.

Aerial view of Antarctica. A prototype of the lunar DAS system for the Artemis missions to the Moon detected tiny tremors from ice movements here. Photo credit: L. McFadden 2008 Measuring a Lunar Quake Using DAS

Since DAS works well measuring tiny tremors induced by ice, it seems like the perfect “next step” in doing lunar seismology. On the Moon, the fiber optic cable would be buried (just as cables are on Earth) a few centimeters below the level of the regolith. It will sit there waiting for the next quake, which probably won’t take long, since the Moon seems to quiver frequently. When one strikes, its seismic waves will move through the ground from the source. They’ll wiggle the cable. That will affect the light-travel path inside. The actions of light hitting thousands of imperfections inside the cable will provide lunar geologists with high-precision data about moonquakes. That includes their origins, travel time, and other aspects of the wave that will help them understand more about the lunar structure they travel through.

The distributed nature of the seismic network will have a big advantage over the Apollo-style individual seismometers used in the past. And, there are other reasons to use DAS, according to Zhai. “Another advantage of using DAS on the Moon is that a fiber optic cable is physically quite resilient to the harsh lunar environment: high radiation, extreme temperatures, and heavy dust,” Zhai said.

Moon Structure and DAS

Zhai is the first author of a paper describing the DAS system, which should allow scientists to detect close to 100 percent of Moon tremors. The paper offers insight into the advantages that DAS offers. In particular, such an array stretched across large areas of the Moon should provide much higher-quality data about even the smallest tremors that shake the surface.

Since the Moon is not tectonically active, its quakes don’t occur from the same causes as they do on Earth. Some happen during the sunset/sunrise period when temperature changes affect the surface. Others happen thanks to Earth’s pull on the Moon, and still others occur because the Moon is still cooling and contracting. Zhai’s paper suggests that DAS could detect about 15 moonquakes per day, and perhaps help better characterize the thermal moonquakes that happen at sunrise/sunset and the deeper ones that occur during perigee and apogee portions of its orbit, and those intrinsic to the Moon’s contraction. In addition, impacts on the Moon also generate quakes. Information about all these events should give planetary scientists a big leg up on understanding more about the lunar interior structure.

The deployment of DAS and other science experiments will be part of the surface operations of the Artemis missions. It will be part of one of the proposed seven-month stays for astronaut teams. Although there is no specific planned date for seismometer deployment, it’s likely to take place no sooner than the mid-2030s. That’s after the planned missions to build shelters, deploy power stations, and other activities to create the lunar bases.

For More Information

A New Type of Seismic Sensor to Detect Moonquakes
Assessing the feasibility of Distributed Acoustic Sensing (DAS) for Moonquake Detection
Lunar Seismology: A Data and Instrumentation Review

The post Artemis Astronauts Will Deploy New Seismometers on the Moon appeared first on Universe Today.

The Transformers are returning to cinemas in 2024 with their first animated movie in nearly 40 years. This is the beginning of Cybertron's end.

The dwarf planet Ceres has some permanently dark craters that hold ice. Astronomers thought the ice was ancient when they were discovered, like in the moon’s permanently shadowed regions. But something was puzzling.

Why did some of these shadowed craters hold ice while others did not?

Ceres was first discovered in 1801 and was considered a planet. Later, it was thought to be the first asteroid ever discovered, since it’s in the main asteroid belt. Since then, our expanding knowledge has changed its definition: we now know it as a dwarf planet.

Even though it was discovered over 200 years ago, it’s only in the last couple of decades that we’ve gotten good looks at its surface features. NASA’s Dawn mission is responsible for most of our knowledge of Ceres’ surface, and it found what appeared to be ice in permanently shadowed regions (PSRs.)

New research shows that these PSRs are not actually permanent and that the ice they hold is not ancient. Instead, it’s only a few thousand years old.

The new research is titled “History of Ceres’s Cold Traps Based on Refined Shape Models,” published in The Planetary Science Journal. The lead author is Norbert Schorghofer, a senior scientist at the Planetary Science Institute.

“The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less.”

Norbert Schorghofer, senior scientist, Planetary Science Institute.

Dawn captured its first images of Ceres while approaching the dwarf planet in January 2015. At that time, it was close enough to capture images as good as Hubble’s. Those images showed craters and a high-albedo site on the surface. Once captured by Ceres, Dawn followed a polar orbit with decreasing altitude. It eventually reached 375 km (233 mi) above the surface, allowing it to see the poles and surface in greater detail.

“For Ceres, the story started in 2016, when the Dawn spacecraft, which orbited around Ceres at the time, glimpsed into these permanently dark craters and saw bright ice deposits in some of them,” Schorghofer said. “The discovery back in 2016 posed a riddle: Many craters in the polar regions of Ceres remain shadowed all year – which on Ceres lasts 4.6 Earth years – and therefore remain frigidly cold, but only a few of them harbor ice deposits.”

As scientists continued to study Ceres, they made another discovery: its massive Solar System neighbours make it wobble.

“Soon, another discovery provided a clue why: The rotation axis of Ceres oscillates back and forth every 24,000 years due to tides from the Sun and Jupiter. When the axis tilt is high and the seasons strong, only a few craters remain shadowed all year, and these are the craters that contain bright ice deposits,” said lead author Schorghofer.

This figure from the research shows how Ceres’ obliquity has changed over the last 25,000 years. As the obliquity varies, sunlight reaches some crater floors that were thought to be PSRs. Image Credit: Schorghofer et al. 2023.

Researchers constructed digital elevation maps (DEMs) of the craters to uncover these facts. They wanted to find out how large and deep the shadows in the craters were, not just now but thousands of years ago. But that’s difficult to do since portions of these craters were in deep shadow when Dawn visited. That made it difficult to see how deep the craters were.

Robert Gaskell, also from the Planetary Science Institute, took on the task. He developed a new technique to create more accurate maps of the craters with data from Dawn’s sensitive Framing Cameras, contributed to the mission by Germany. With improved accuracy, these maps of the crater floors could be used in ray tracing to show sunlight penetrated the shadows as Ceres wobbled over thousands of years.

This figure from the study shows some of the DEMs the researchers developed for craters on Ceres. White regions represent sunlit areas, while the coloured contours represent PSRs for different axial tilts. Image Credit: Schorghofer et al. 2023.

The DEMs in the above image show that at 20 degrees obliquity, none of the craters are in permanent shadow. That means none of them have truly permanent PSRs. “A PSR starts to emerge in Bilwis crater at about 18°, and they emerge at lower obliquities at the other six study sites. This implies that the ice deposits are remarkably young,” the researchers write in their paper.

This figure from the research shows PSRs in the north-polar region of Ceres. The colour scale shows how oblique each crater is. The research shows that 14,000 years ago, none of these were PSRs, and the ice they hold now is only 6,000 years old. Image Credit: Schorghofer et al. 2023.

About 14,000 years ago, Ceres reached its maximum axial tilt. At that time, no craters were PSRs. Any ice in these craters would’ve been sublimated into space. “That leaves only one plausible explanation: The ice deposits must have formed more recently than that. The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less. Considering that Ceres is well over 4 billion years old, that is a remarkably young age,” Schorghofer said.

So, where did the ice come from?

There must be some source if the ice is young and keeps reforming during maximum obliquity. The only plausible one is Ceres itself.

“Ceres is an ice-rich object, but almost none of this ice is exposed on the surface. The aforementioned polar craters and a few small patches outside the polar regions are the only ice exposures. However, ice is ubiquitous at shallow depths – as discovered by PSI scientist Tom Prettyman and his team back in 2017 – so even a small dry impactor could vaporize some of that ice.” Schorghofer said. “A fragment of an asteroid may have collided with Ceres about 6,000 years ago, which created a temporary water atmosphere. Once a water atmosphere is generated, ice would condense in the cold polar craters, forming the bright deposits that we still see today. Alternatively, the ice deposits could have formed by avalanches of ice-rich material. This ice would then survive in only the cold shadowed craters. Either way, these events were very recent on an astronomical time scale.”

There are other potential sources of water ice. Ceres has a very thin, transient water atmosphere. The water could come from cryovolcanic processes and then be trapped and frozen in shadowed regions.

Ceres also has a single cryovolcano: Ahuna Mons. It’s at least a couple hundred million years old and long dormant. There are dozens of other dormant potential cryovolcanoes, too. But these likely aren’t the water source.

There’s ample water ice at shallow levels in Ceres. If the dwarf planet erodes over time, mass-wasting could expose and release water that freezes in the craters. “The few ice deposits that have been detected spectroscopically outside the polar regions are indeed often associated with landslides, and the sunlit portion of the ice deposit in Zatik crater is best explained by a recent mass wasting event,” the authors explain.

Ceres has been through a lot. As an ancient protoplanet that’s survived to this day, it holds important clues to the Solar System. Though its craters don’t hold ancient ice like once thought, deeper study is revealing the dwarf planet’s true nature.

“The ice deposits in the Cerean PSRs indicate an active water cycle; ice is either repeatedly captured and lost or frequently exposed, or both,” the authors conclude.

The post Ice Deposits on Ceres Might Only Be a Few Thousand Years Old appeared first on Universe Today.

3 min read

Sols 4159-4160: A Fully Loaded First Sol This image was taken by Chemistry & Camera (ChemCam) onboard NASA’s Mars rover Curiosity on Sol 4158 (2024-04-17 07:52:27 UTC). NASA/JPL-Caltech/LANL

Earth planning date: Wednesday, April 17, 2024

Curiosity continues to make progress along the margin of upper Gediz Vallis ridge, investigating the broken bedrock in our workspace and acquiring images of the ridge deposit as the rover drives south.

Today’s 2-sol plan focused on a DRT, contact science, and drive on the first sol, followed by untargeted remote sensing on the second sol.  The team had to make some decisions at the start of planning about whether to drive on the first or second sol of this plan, and how that would affect the upcoming weekend activities.  As it turned out, the team was able to fit all of the desired contact science and remote sensing activities on the first sol, in addition to the drive on the first sol, which means we’ll be able to downlink more information about our end-of-drive location to better inform planning for the weekend.  Weekend plans provide opportunities for a lot of great contact science, so it will be really helpful to have that additional data down for planning.

That means the first sol of this plan is fully loaded!  The plan begins with a DRT activity to expose a fresh surface on the bedrock target “Tilden Lake,” followed by APXS integrations to investigate its composition. Then the Geology theme group planned several hours of remote sensing activities, including ChemCam LIBS on the bedrock target “Curry Village,” which has a similar “dragon scale” texture (or “tire tracks”) to what we had observed in the previous workspace. This big remote sensing block also includes ChemCam long distance RMI mosaics to assess the stratigraphy at Gediz Vallis ridge and the distant butte Kukenan.  These long distance RMI images reveal a lot of great detail about distant targets, like the diversity of clasts at Gediz Vallis ridge, as seen in the above image.  

The plan also includes a number of Mastcam activities to characterize local textures, sedimentary structures, dark rocks, and sandy aeolian bedforms (known as Transverse Aeolian Ridges, aka TARs) in a nearby trough.  The Environmental theme group also planned activities to monitor the movement of fines on the rover deck, search for dust devils, and monitor atmospheric dust.  After this big remote sensing block, Curiosity will use MAHLI to image the contact science target, and then continue driving south.  The second sol includes untargeted activities like an autonomously selected ChemCam AEGIS target, additional Navcam deck monitoring, and Navcam line-of-sight observations. After the drive we’ll take post drive imaging to prepare for the next plan.

Looking forward to seeing what other surprises our next workspace will reveal!

Written by Lauren Edgar, Planetary Geologist at USGS Astrogeology Science Center

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Millions of viewers were wowed by last week’s total solar eclipse. Now, we get to see the eclipse from another angle: space.

The post See Amazing Views of the April 8th Total Solar Eclipse from Space appeared first on Sky & Telescope.

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