The crater’s secrets are finally within reach. A team of planetary scientists has made a groundbreaking discovery that allows us to peer beneath the dusty surface of Mars and other planetary bodies. By studying the layers of rock blasted out of craters by impacts, researchers can now infer the properties of materials hidden beneath the impact point.

Historically, scientists have relied on the size and shape of impact craters to understand what lies beneath. However, this new study reveals that the ejecta blanket – a ring of material thrown out during an impact – is sensitive to subsurface properties as well. This gives us a fresh observable on the surface to help constrain materials present underground.

The research was led by Aleksandra Sokolowska, a UKRI fellow at Imperial College London. While working as a postdoctoral researcher at Brown University, she collaborated with Ingrid Daubar and Gareth Collins to develop computer simulations that capture the physics of planetary impacts. These simulations allowed Sokolowska to test various subsurface materials and layering patterns, predicting how they would affect the distance debris travels.

The results showed that different subsurface materials produce distinct ejecta patterns. To add credibility to these findings, the team analyzed two fresh impact craters on Mars, confirming that differences in ejecta radius can be measured from orbit with cameras like HiRISE onboard the Mars Reconnaissance Orbiter.

One of the craters was located over solid bedrock, while the other had subsurface ice. Consistent with model predictions, the crater on the icy subsurface had a much smaller ejecta blanket than the one on bedrock. These findings help confirm that differences in ejecta radius reflect known subsurface properties.

This breakthrough method could be useful for several current and upcoming spacecraft missions, including the European Space Agency’s Hera spacecraft arriving at Dimorphos, an asteroid hit by NASA to test deflection capabilities. Sokolowska suggests that the ejecta around this crater might hold valuable information about the asteroid’s interior.

The Great Enigma of Titan: Why the Moon’s Rivers Are Missing Deltas

Titan, Saturn’s largest moon, is a geological treasure trove that has long fascinated planetary scientists. With its thick atmosphere, liquid methane and ethane seas, and rivers that flow across its surface, Titan offers a unique window into the moon’s history and evolution. However, a new study published in the Journal of Geophysical Research: Planets reveals a surprising absence of river deltas on Titan – a feature that is common on Earth but mysteriously missing on this alien world.

“As a geomorphologist, it’s kind of disappointing to see that Titan doesn’t have the same type of deltas as we do on Earth,” said Sam Birch, an assistant professor in Brown University’s Department of Earth, Environmental and Planetary Sciences who led the work. “But at the same time, it raises a host of new questions.”

Titan’s liquid methane and ethane rivers should be perfectly capable of carrying and depositing sediment, forming deltas at their mouths. However, when Birch and his colleagues analyzed Cassini SAR data, they found that only about 1.3% of Titan’s large rivers have deltas – a stark contrast to the nearly 100% delta formation on Earth.

“It’s not entirely clear why Titan generally lacks deltas,” Birch said. “The fluid properties of Titan’s rivers should make them perfectly capable of carrying and depositing sediment.”

The researchers suggest that rapid changes in sea levels, winds, and tidal currents along Titan’s coasts may prevent delta formation. However, more research is needed to fully understand this phenomenon.

“This is really not what we expected,” Birch said. “But Titan does this to us a lot. I think that’s what makes it such an engaging place to study.”

The new analysis of Cassini SAR data also revealed pits of unknown origin deep within lakes and seas on Titan, as well as deep channels on the floors of these seas that seem to have been carved by river flows – but it’s not clear how they got there.

All of these surprises will require more research to fully understand. As Birch said, “This is really not what we expected, but Titan does this to us a lot. I think that’s what makes it such an engaging place to study.”

The long-standing debate over the origin of water on Earth has finally been put to rest by a team of researchers at the University of Oxford. Using a rare type of meteorite known as an enstatite chondrite, which has a composition analogous to that of the early Earth (4.55 billion years ago), they have uncovered crucial evidence for the origin of water on our planet.

The research team analyzed the elemental composition of a meteorite known as LAR 12252, originally collected from Antarctica. They used an elemental analysis technique called X-Ray Absorption Near Edge Structure (XANES) spectroscopy at the Diamond Light Source synchrotron at Harwell, Oxfordshire. This powerful tool allowed them to search for sulphur-bearing compounds in the meteorite’s structure.

When scanning the sample, the team focussed their efforts on the non-crystalline parts of the chondrules, where hydrogen had been found before. However, serendipitously, they discovered that the matrix itself was incredibly rich in hydrogen sulphide. In fact, their analysis found that the amount of hydrogen in the matrix was five times higher than that of the non-crystalline sections.

This finding suggests that the material which our planet was built from was far richer in hydrogen than previously thought. Without hydrogen, a fundamental elemental building-block of water, it would have been impossible for our planet to develop the conditions to support life.

The research team’s discovery contradicts the popular theory that water on Earth originated from asteroids bombarding its surface. Instead, their findings suggest that Earth had the hydrogen it needed to create water from when it first formed. This supports the idea that the formation of water on Earth was a natural process, rather than a fluke of hydrated asteroids bombarding our planet after it formed.

Tom Barrett, DPhil student in the Department of Earth Sciences at the University of Oxford, who led the study, said: “We were incredibly excited when the analysis told us the sample contained hydrogen sulphide — just not where we expected! Because the likelihood of this hydrogen sulphide originating from terrestrial contamination is very low, this research provides vital evidence to support the theory that water on Earth is native — that it is a natural outcome of what our planet is made of.”

Co-author Associate Professor James Bryson (Department of Earth Sciences, University of Oxford) added: “A fundamental question for planetary scientists is how Earth came to look like it does today. We now think that the material that built our planet — which we can study using these rare meteorites — was far richer in hydrogen than we thought previously. This finding supports the idea that the formation of water on Earth was a natural process, rather than a fluke of hydrated asteroids bombarding our planet after it formed.”

The discovery of this hidden secret to Earth’s water origin has significant implications for our understanding of the planet’s history and evolution. It suggests that the conditions necessary for life to arise were present from the very beginning, and that the formation of water was an integral part of the process.