Scientists Piece Together the Shoreline of an Ancient Ocean on Mars

Stitched together from 28 images, this view from NASA's Curiosity Mars rover was captured after the rover ascended the steep slope of a geologic feature called "Greenheugh Pediment." In the distance at the top of the image is the floor of Gale Crater, which is near a region called Aeolis Dorsa that researchers believe was once a massive ocean. The layered structure of the rocks indicated they were created by waterborne sediment. Credit: NASA/JPL-Caltech/MSSS.

Scientists have long suspected that Mars was once warm and wet in its ancient past. The Mars Ocean Hypothesis says that the planet was home to a large ocean around 4 billion years ago. The ocean filled the Vastitas Borealis basin in the planet’s northern hemisphere. The basin is 4–5 km (2.5–3 miles) below Mars’ mean elevation.

A new topographic map of Mars reinforces the hypothesis and adds more detail.

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Scientists Have Been Underestimating the Asteroid That Created the Biggest Known Crater on Earth

South Africa's Vredefort Crater is Earth's largest impact crater. New Research clarifies the power of the impact and its catastrophic effects. Image Credit: NASA Earth Observatory image by Lauren Dauphin / University of Rochester illustration by Julia Joshpe

Ancient impacts played a powerful role in Earth’s complex history. On other Solar System bodies like the Moon or Mercury, the impact history is preserved on their surfaces because there’s nothing to erase it. But Earth’s geologic activity has erased the evidence of impact craters over time, with some help from erosion.

Earth’s complex history has elevated its status among its Solar System siblings and created a world that’s rippling with life. Ancient giant impacts have played a role in that history, bringing catastrophe and disruption and irrevocably changing the course of events. Deciphering the role these giant impacts played is difficult since the evidence is missing or severely degraded. So how do scientists approach this problem?

One crater at a time.

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A Geologic map of the Entire Moon has Been Released at 1:2,500,000-Scale

Chinese scientists took 10 years to create the most detailed map yet of the Moon. Image Credit: Jinzhu Ji et al. 2022.

Chinese scientists have created the most detailed map of the Moon yet. It took them 10 years and involved hundreds of researchers. The new map will be a boon to lunar exploration and for anyone who just wants to study our natural satellite in more detail.

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Pluto’s Surface was Shaped by Ice Volcanoes

New Horizons mission scientists have determined that cryovolcanic activity most likely created unique structures on Pluto not yet seen anywhere else in the solar system. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Isaac Herrera/Kelsi Singer

For all of Earth’s geological diversity and its long history, the planet has never had ice volcanoes. But Pluto has. And that cryovolcanism has shaped some of the ice dwarf’s surface features.

The resulting structures are unique in the Solar System.

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This is Where the Mars Sample Return Mission Could be Landing

This image was acquired based on a hopeful scenario in which the Perseverance rover has an extended mission or two and travels outside of Jezero Crater to explore terrains to the west. In this scenario, the decision could be made to land the Mars Sample Return (MSR) mission here to pick up samples collected by Perseverance. MSR will probably not land here, but acquisition of a HiRISE stereo pair provides the data needed to assess the risk of landing. The cutout shows that there are diverse colors and textures, so this would be an interesting region to explore. Image Credit: NASA/JPL/UArizona

NASA’s Perseverance Rover is busy exploring Jezero Crater on Mars. Part of its mission is to collect samples for retrieval by a future mission. NASA and the ESA haven’t determined where the sample return mission will land yet.

That depends on the Perseverance mission and how it spends the rest of its time on Mars. But we know of one possible—albeit ambitious—landing spot: just west of Jezero Crater.

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These are Star Dunes on Mars, Formed When the Wind Comes From Many Different Directions

An amazing aspect of Mars that is captured in many HiRISE images is geologic diversity within a small area. This image, of a crater in the Tyrrhena Terra region, was targeted to look at the geologic aspects of possible clays detected with the CRISM instrument. Image Credit: NASA/JPL/UArizona

Missions to Mars are expensive, even orbiters. They’re there to do science, not take pretty pictures. But sometimes Mars’ beauty is captured inadvertently, usually with some science mixed in.

That’s the case with this picture of star dunes captured by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter.

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What’s it Like Inside a Super-Earth?

This artist’s impression shows a Super-Earth orbiting a Sun-like star. HD 85512 in the southern constellation of Vela (The Sail). This planet is one of sixteen super-Earths discovered by the HARPS instrument on the 3.6-metre telescope at ESO’s La Silla Observatory. This planet is about 3.6 times as massive as the Earth lis at the edge of the habitable zone around the star, where liquid water, and perhaps even life, could potentially exist. Credit: ESO

We know a ton about the inside of Earth. We know it has both an inner core and an outer core and that the churning and rotation create a protective magnetosphere that shields life from the Sun’s radiative power. It has a mantle, primarily solid but also home to magma. We know it has a crust, where we live, and plate tectonics that moves the continents around like playthings.

But what about Super-Earths? We know they’re out there; we’ve found them. What do we know about their insides? Earth’s structure, and its ability to support life, are shaped by the extreme pressure and density in its interior. The pressure and temperature inside Super-Earths are even more powerful. How does it shape these planets and affect their habitability?

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It’s Been Constantly Raining Meteors on Mars for 600 Million Years. Earth too.

An impact crater on Mars. Image Credit: NASA

New research shows that Mars has faced a constant rain of meteors during the last 600 million years. This finding contradicts previous research showing that the impact rate has varied, with prominent activity spikes. Why would anyone care how often meteors rained down on Mars, a planet that’s been dead for billions of years?

Because whatever Mars was subjected to, Earth was also likely subjected to.

Who wouldn’t want to know our planet’s history?

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The Moon’s Crust was Formed From a Frozen Slushy Magma

Magma ocean and first rocky crust on the Moon. Image Credit: NASA/Goddard Space Flight Center

Scientists’ detailed study of the Moon dates back to the Apollo missions when astronauts brought rock samples from the lunar surface back to Earth for analysis. Apollo 11 gathered samples from the lunar highland regions, the pale areas on the Moon’s surface easily seen from Earth. The highlands are made of a relatively light rock called anorthosite, which formed early in the history of the Moon, between 4.3 and 4.5 billion years ago.

There’s some mystery involved in the anorthosite formation on the Moon. The age of the anorthosite highlands doesn’t match how long it took for the Moon’s magma ocean to cool. But scientists behind a new study think they’ve solved that mystery.

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Remember When Life was Found in a Martian Meteorite? Turns out, it was Just Geology

The Alan Hills meteorite is a part of history to Mars aficionados. It came from Mars and meteorite hunters discovered in Antarctica in 1984. Scientists think it’s one of the oldest chunks of rock to come from Mars and make it to Earth.

The meteorite made headlines in 1996 when a team of researchers said they found evidence of life in it.

Did they?

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