NASA’s Mars Reconnaissance Orbiter (MRO) has clicked a stunning picture of the Red Planet’s surface showing frozen sand dunes in the northern hemisphere, resembling a kidney bean. The photo, taken by the High-Resolution Imaging Science Experiment (HiRISE) camera in September 2022 and only released to the public last month, could help find if conditions on Mars could have sustained life a long time ago.

Unlike the dunes on Earth which are constantly in motion, the kidney bean-shaped dunes on Mars appear surprisingly motionless. As per NASA, the dunes in the photo are covered in a layer of carbon dioxide frost during the winter on Mars. During the cold months, the planet’s poles can experience nighttime temperatures as low as -123 degrees Celsius which creates ideal conditions for both snowfall and the formation of frost. But unlike Earth’s snow, Mars’ snow comes in two forms: water ice and frozen carbon dioxide, or dry ice.

The frost, made of both water ice and carbon dioxide ice, stops the wind from carrying up the sand and prevents the dunes from migrating until the spring thaw comes. Studying how the carbon dioxide frost changes under current condition conditions could help better predict the past climate on Mars.

Watch | NASA’s Rover Captures ‘Googly Eye’ Eclipse On Mars

Life on Mars?

Scientists have long been seeking answers about the presence of life on Mars. In October last year, a NASA study stated that microbes might find a potential home beneath the frozen water on the Red Planet’s surface. The scientists discovered that the amount of sunlight that penetrates the water ice could be enough for photosynthesis to occur in the shallow pools of meltwater beneath the surface of that ice.

A month later, a study by researchers at Harvard’s Paleomagnetics Lab revealed that Mars’ magnetic field, which could have supported life, may have lasted much longer than previously thought.

While Mars is now cold, barren and rocky, evidence suggests that the magnetic field may have lasted until 3.9 billion years ago, compared with previous estimates of 4.1 billion years — making the Red Planet a prime candidate for a thriving environment for life.

The extra 200 million years overlap with the era when the Martian surface became covered with water, the evidence for which has been gathered by several rovers sent by NASA.

Water is ubiquitous on Earth – about 70% of Earth’s surface is covered by the stuff. Water is in the air, on the surface and inside rocks. Geologic evidence suggests water has been stable on Earth since about 4.3 billion years ago.

The history of water on early Mars is less certain. Determining when water first appeared, where and for how long, are all burning questions that drive Mars exploration. If Mars was once habitable, some amount of water was required.

We studied the mineral zircon in a meteorite from Mars and found evidence that water was present when the zircon crystal formed 4.45 billion years ago. Our results, published in the journal Science Advances today, may represent the oldest evidence for water on Mars.

A wet red planet

Water has long been recognised to have played an important role in early Martian history. To place our results in a broader context, let’s first consider what “early Mars” means in terms of the Martian geological timescale, and then consider the different ways to look for water on Mars.

Like Earth, Mars formed about 4.5 billion years ago. The history of Mars has four geological periods. These are the Amazonian (from today back to 3 billion years), the Hesperian (3 billion to 3.7 billion years ago), the Noachian (3.7 billion to 4.1 billion years ago) and the Pre-Noachian (4.1 billion to about 4.5 billion years ago).

Evidence for water on Mars was first reported in the 1970s when NASA’s Mariner 9 spacecraft captured images of river valleys on the Martian surface. Later orbital missions, including Mars Global Surveyor and Mars Express, detected the widespread presence of hydrated clay minerals on the surface. These would have needed water.

The Martian river valleys and clay minerals are mainly found in Noachian terrains, which cover about 45% of Mars. In addition, orbiters also found large flood channels – called outflow channels – in Hesperian terrains. These suggest the short-lived presence of water on the surface, perhaps from groundwater release.

Most reports of water on Mars are in materials or terrains older than 3 billion years. More recent than that, there isn’t much evidence for stable liquid water on Mars.

But what about during the Pre-Noachian? When did water first show up on Mars?

A window to Pre-Noachian Mars

There are three ways to hunt for water on Mars. The first is using observations of the surface made by orbiting spacecraft. The second is using ground-based observations such as those taken by Mars rovers.

The third way is to study Martian meteorites that have landed on Earth, which is what we did.

In fact, the only Pre-Noachian material we have available to study directly is found in meteorites from Mars. A small number of all meteorites that have landed on Earth have come from our neighbouring planet.

An even smaller subset of those meteorites, believed to have been ejected from Mars during a single asteroid impact, contain Pre-Noachian material.

The “poster child” of this group is an extraordinary rock called NWA7034, or Black Beauty.

Black Beauty is a famous Martian meteorite made up of broken-up surface material, or regolith. In addition to rock fragments, it contains zircons that formed from 4.48 billion to 4.43 billion years ago. These are the oldest pieces of Mars known.

While studying trace elements in one of these ancient zircons we found evidence of hydrothermal processes – meaning they were exposed to hot water when they formed in the distant past.

Trace elements, water and a connection to ore deposits

The zircon we studied is 4.45 billion years old. Within it, iron, aluminium and sodium are preserved in abundance patterns like concentric layers, similar to an onion.

This pattern, called oscillatory zoning, indicates that incorporation of these elements into the zircon occurred during its igneous history, in magma.

The problem is that iron, aluminium and sodium aren’t normally found in crystalline igneous zircon – so how did these elements end up in the Martian zircon?

The answer is hot water.

In Earth rocks, finding zircon with growth zoning patterns for elements like iron, aluminium and sodium is rare. One of the only places where it has been described is from Olympic Dam in South Australia, a giant copper, uranium and gold deposit.

The metals in places like Olympic Dam were concentrated by hydrothermal (hot water) systems moving through rocks during magmatism.

Hydrothermal systems form anywhere that hot water, heated by volcanic plumbing systems, moves through rocks. Spectacular geysers at places like Yellowstone National Park in the United States form when hydrothermal water erupts at Earth’s surface.

Finding a hydrothermal Martian zircon raises the intriguing possibility of ore deposits forming on early Mars.

Previous studies have proposed a wet Pre-Noachian Mars. Unusual oxygen isotope ratios in a 4.43 billion-year-old Martian zircon were previously interpreted as evidence for an early hydrosphere. It has even been suggested that Mars may have had an early global ocean 4.45 billion years ago.

The big picture from our study is that magmatic hydrothermal systems were active during the early formation of Mars’ crust 4.45 billion years ago.

It’s not clear whether this means surface water was stable at this time, but we think it’s possible. What is clear is that the crust of Mars, like Earth, had water shortly after it formed – a necessary ingredient for habitability.

This article is republished from The Conversation under a Creative Commons license. Read the original article here.

Elon Musk and Neil de Grasse Tyson have clashed once again with the latter claiming that the billionaire will not be able to fund his quest to set up civilisation on Mars. Speaking to American talk show host, Bill Maher, Mr Tyson commented on the feasibility of travelling to Mars, adding that the investors would never agree to the idea as it had no return on investment. For a long time, Mr Musk has posited that Mars colonisation is the only way for humanity to survive while Mr Tyson wants humankind to focus on immediate challenges present on Earth instead of expending resources in outer space.

During the interview, Mr Maher asked Mr Tyson how long would it take for the SpaceX boss to “realistically send humans to Mars”.

“How badly would we have to rat f**k Earth before it’s worse than a place that’s 200 below zero with no air and no water with six months to reach it?!” quizzed Mr Maher.

To which, Mr Tyson, who hosted the TV series Cosmos, developed by Carl Sagan, replied: “My read of the history of space exploration is such that we do big, expensive things only when it’s geopolitically expedient, such as we feel threatened by an enemy.”

“And so for him to just say, let’s go to Mars because it’s the next thing to do. What is that venture capitalist meeting look like? ‘So, Elon, what do you want to do?’ ‘I want to go to Mars?’ ‘How much will it cost?’ ‘$1 trillion.’ ‘Is it safe?’ ‘No. People will probably die.’ ‘What’s the return on the investment?’ ‘Nothing.’ That’s a five-minute meeting. And it doesn’t happen,” he added.

Wow, they really don’t get it.

Mars is critical to the long-term survival of consciousness.

Also, I’m not going to ask any venture capitalists for money. I realize that it makes no sense as an investment. That’s why I’m gathering resources. https://t.co/XVCpHKlusD

— Elon Musk (@elonmusk) November 23, 2024

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Musk responds

After the video of Mr Tyson’s monologue went viral, the Tesla CEO took to X (formerly Twitter) and issued a response.

“Wow, they really don’t get it. Mars is critical to the long-term survival of consciousness. Also, I’m not going to ask any venture capitalists for money. I realise that it makes no sense as an investment. That’s why I’m gathering resources,” wrote Mr Musk, adding the ‘slapping forehead in disbelief’ emoji.

In a separate post, Mr Musk added even if he failed at creating a Mars colony that can grow without continuous support from Earth, “the absurdly ambitious nature of the goal nonetheless results in the creation of alien-level technology that is crushingly better than competitors who merely aim for Earth orbit”.

Mr Musk’s SpaceX is hoping to use the Starship’s reusability factor to build a colony on Mars. In September, the company announced that it would be launching its first uncrewed mission to Mars in the next two years.  

Sydney:

Australian researchers have discovered the oldest direct evidence of hot water activity on Mars, revealing that the planet may have once been habitable.

In a study published on Saturday, a team led by researchers from Curtin University in Western Australia analyzed a 4.45 billion-year-old zircon grain from the famous Martian meteorite NWA7034, also known as Black Beauty, that was found in the Sahara Desert in 2011.

The researchers found that the grain of zircon, a type of mineral, contained geochemical fingerprints of water-rich fluids, suggesting that water was present during early Martian magmatic activity.

Aaron Cavosie, a co-author of the study from Curtin’s School of Earth and Planetary Sciences, said that the discovery would open up new avenues for understanding ancient Martian hydrothermal systems, as well as the planet’s past capacity to support life.

“We used nano-scale geochemistry to detect elemental evidence of hot water on Mars 4.45 billion years ago,” he said, Xinhua news agency reported.

“Hydrothermal systems were essential for the development of life on Earth and our findings suggest Mars also had water, a key ingredient for habitable environments, during the earliest history of crust formation.”

He said that even though Mars’ crust endured major meteorite impacts that caused surface upheaval, the research shows that water was present on the planet during the early Pre-Noachian period prior to about 4.1 billion years ago.

The study also involved researchers from the University of Adelaide and was led by Jack Gillespie, a former research associate at Curtin’s School of Earth and Planetary Sciences now at the University of Lausanne in Switzerland.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

Washington:

With the assistance of China’s Zhurong rover, scientists have gathered fresh evidence that Mars was home to an ocean billions of years ago – a far cry from the dry and desolate world it is today.

Scientists said on Thursday that data obtained by Zhurong, which landed in the northern lowlands of Mars in 2021, and by orbiting spacecraft indicated the presence of geological features indicative of an ancient coastline. The rover analyzed rock on the Martian surface in a location called Utopia Planitia, a large plain in the planet’s northern hemisphere.

The researchers said data from China’s Tianwen-1 Orbiter, NASA’s Mars Reconnaissance Orbiter, and the robotic six-wheeled rover indicated the existence of a water ocean during a period when Mars might already have become cold and dry and lost much of its atmosphere.

They described surface features such as troughs, sediment channels, and mud volcano formations indicative of a coastline, with evidence of both shallow and deeper marine environments.

“We estimate the flooding of the Utopia Planitia on Mars was approximately 3.68 billion years ago. The ocean surface was likely frozen in a geologically short period,” said Hong Kong Polytechnic University planetary scientist Bo Wu, lead author of the study published in the journal Scientific Reports.

The ocean appears to have disappeared by approximately 3.42 billion years ago, the researchers said.

“The water was heavily silted, forming the layering structure of the deposits,” Hong Kong Polytechnic University planetary scientist and study co-author Sergey Krasilnikov added.

Like Earth and our solar system’s other planets, Mars formed about 4.5 billion years ago. At the time the ocean apparently existed, it might already have begun its transition away from being a hospitable planet.

“The presence of an ancient ocean on Mars has been proposed and studied for several decades, yet significant uncertainty remains,” Wu said. “These findings not only provide further evidence to support the theory of a Martian ocean but also present, for the first time, a discussion on its probable evolutionary scenario.”

Water is seen as a key ingredient for life, and the past presence of an ocean raises the prospect that Mars at least at one time was capable of harboring microbial life.

“At the beginning of Mars’ history, when it probably had a thick, warm atmosphere, microbial life was much more likely,” Krasilnikov said.

The solar-powered Zhurong, named after a mythical Chinese god of fire, began its work using six scientific instruments on the Martian surface in May 2021 and went into hibernation in May 2022, likely met with excessive accumulation of sand and dust, according to its mission designer. It exceeded its original mission time span of three months.

Researchers have sought to better understand what happened to all the water that once was present on the Martian surface. Another study, published in August and based on seismic data obtained by NASA’s robotic InSight lander, indicated that an immense reservoir of liquid water may reside deep under the surface within fractured igneous rocks.

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

Is there life on Mars? Scientists have been seeking an answer to this question for a long time. Although no concrete evidence has been found till date, a latest study by NASA has sparked curiosity. The US space agency suggests that microbes might find a potential home beneath the frozen water on the red planet’s surface.

Based on computer modelling, the authors of the study have discovered that the amount of sunlight that penetrates the water ice could be enough for photosynthesis to occur in the shallow pools of meltwater beneath the surface of that ice.

The process of photosynthesis is utilised by plants and other organisms for converting light energy into chemical energy in search of food.

On the Earth, similar pools of water that form within ice are found to teem with life, including algae, fungi, and microscopic cyanobacteria — all of them derive energy from photosynthesis.

What does the study suggest?

The NASA research was led by Aditya Khuller, who is associated with the space agency’s Jet Propulsion Laboratory (JPL) in Southern California. The paper was published in Nature Communications Earth & Environment.

“If we’re trying to find life anywhere in the universe today, Martian ice exposures are probably one of the most accessible places we should be looking,” Khuller said.

Since Mars has two kinds of ice — frozen water and frozen carbon dioxide — the research team looked at the water ice as a potential host of life.

Tracing its origin, the researchers said that large amounts of it had formed from snow mixed with dust which had fallen on the surface during a series of Martian ice ages in the past million years. The ancient snow, which has now solidified into ice, is still peppered with specks of dust, it added.

Even though these dust particles may obscure light in the ice’s deeper layers, they hold the key to explaining how subsurface pools of water could form within ice after getting exposed to the Sun.

“Dark dust absorbs more sunlight than the surrounding ice, potentially causing the ice to warm up and melt up to a few feet below the surface,” NASA states.

The study’s co-author, Phil Christensen of Arizona State University in Tempe, has been studying ice on Mars for the past few decades.

“Dense snow and ice can melt from the inside out, letting in sunlight that warms it like a greenhouse, rather than melting from the top down,” he said.

Aditya Khuller and his team now hope to re-create some of Mars’ dusty ice in a lab to study it closely.

Mars is one of Earth’s nearest space neighbours, and the idea of finding extraterrestrial life there, only a short rocket journey away, has long attracted human curiosity. Such life has not been discovered. However, since NASA and other space agencies have started employing robotic technology to examine the Red Planet’s surface and skies, pictures of odd formations and features have continued to excite scientists and space enthusiasts curiosity and inspire both fear and optimism.

Also Read | “Bear Face” Spotted On Mars As NASA Observes Rock Formation

From an open travel book to the face of a teddy bear, frozen mineral flowers, a mysterious doorway, and fossilised animal tracks, there are numerous intriguing objects on Mars that seem out of place on a barren, dusty planet, igniting human curiosity.

According to Science Alert, an image captured by the Perseverance rover in the course of its duties is one of the grisliest yet: it looks, for all the world, like a desiccated, decaying human head, severed from any body, just withering away under the harsh light of the Sun.

NASA’s Mars Perseverance rover acquired this image using its Right Mastcam-Z camera. Mastcam-Z is a pair of cameras located high on the rover’s mast. This image was acquired on September 27, 2024 (Sol 1282) at the local mean solar time of 11:50:05.

It looks like a chunk of sedimentary sandstone, not unlike other rocks around it. Which isn’t unusual for Mars, especially where water is once thought to have flowed, according to Science Alert.

When I was in middle school, my biology teacher showed our class the sci-fi movie “Star Trek III: The Search for Spock.”

The plot drew me in, with its depiction of the “Genesis Project” – a new technology that transformed a dead alien world into one brimming with life.

After watching the movie, my teacher asked us to write an essay about such technology. Was it realistic? Was it ethical? And to channel our inner Spock: Was it logical? This assignment had a huge impact on me.

Fast-forward to today, and I’m an engineer and professor developing technologies to extend the human presence beyond Earth.

For example: I’m working on advanced propulsion systems to take spacecraft beyond Earth’s orbit. I’m helping to develop lunar construction technologies to support NASA’s goal of long-term human presence on the Moon. And I’ve been on a team that showed how to 3D-print habitats on Mars.

To sustain people beyond Earth will take a lot of time, energy and imagination. But engineers and scientists have started to chip away at the many challenges.

A partial checklist: Food, water, shelter, air

After the Moon, the next logical place for humans to live beyond Earth is Mars.

But is it possible to terraform Mars – that is, transform it to resemble the Earth and support life? Or is that just the musings of science fiction?

To live on Mars, humans will need liquid water, food, shelter and an atmosphere with enough oxygen to breathe and thick enough to retain heat and protect against radiation from the Sun.

But the Martian atmosphere is almost all carbon dioxide, with virtually no oxygen. And it’s very thin – only about 1% as dense as the Earth’s.

The less dense an atmosphere, the less heat it can hold on to. Earth’s atmosphere is thick enough to retain enough heat to sustain life by what’s known as the greenhouse effect.

But on Mars, the atmosphere is so slight that the nighttime temperature drops routinely to 150 degrees below zero Fahrenheit (-101 degrees Celsius).

So what’s the best way to give Mars an atmosphere?

Although Mars has no active volcanoes now – at least as far as we know – scientists could trigger volcanic eruptions via nuclear explosions. The gases trapped deep in a volcano would be released and then drift into the atmosphere. But that scheme is a bit harebrained, because the explosions would also introduce deadly radioactive material into the air.

A better idea: Redirecting water-rich comets and asteroids to crash into Mars. That too would release gases from below the planet’s surface into the atmosphere while also releasing the water found in the comets. NASA has already demonstrated that it is possible to redirect asteroids – but relatively large ones, and lots of them, are needed to make a difference.

Making Mars cozy

There are numerous ways to heat up the planet. For instance, gigantic mirrors, built in space and placed in orbit around Mars, could reflect sunlight to the surface and warm it up.

One recent study proposed that Mars colonists could spread aerogel, an ultralight solid material, on the ground. The aerogel would act as insulation and trap heat. This could be done all over Mars, including the polar ice caps, where the aerogel could melt the existing ice to make liquid water.

To grow food, you need soil. On Earth, soil is composed of five ingredients: minerals, organic matter, living organisms, gases and water.

But Mars is covered in a blanket of loose, dustlike material called regolith. Think of it as Martian sand. The regolith contains few nutrients, not enough for healthy plant growth, and it hosts some nasty chemicals called perchlorates, used on Earth in fireworks and explosives.

Cleaning up the regolith and turning it into something viable wouldn’t be easy. What the alien soil needs is some Martian fertilizer, maybe made by adding extremophiles to it – hardy microbes imported from Earth that can survive even the harshest conditions. Genetically engineered organisms are also a possibility.

Through photosynthesis, these organisms would begin converting carbon dioxide to oxygen. Eventually, as Mars became more life-friendly to Earthlike organisms, colonists could introduce more complex plants and even animals.

Providing oxygen, water and food in the right proportions is extraordinarily complex. On Earth, scientists have tried to simulate this in Biosphere 2, a closed-off ecosystem featuring ocean, tropical and desert habitats. Although all of Biosphere 2’s environments are controlled, even there scientists struggle to get the balance right. Mother Nature really knows what she is doing.

A house on Mars

Buildings could be 3D-printed; initially, they would need to be pressurized and protected until Mars acquired Earthlike temperatures and air. NASA’s Moon-to-Mars Planetary Autonomous Construction Technologies program is researching how to do exactly this.

There are many more challenges. For example, unlike Earth, Mars has no magnetosphere, which protects a planet from solar wind and cosmic radiation. Without a magnetic field, too much radiation gets through for living things to stay healthy. There are ways to create a magnetic field, but so far the science is highly speculative.

In fact, all of the technologies I’ve described are far beyond current capabilities at the scale needed to terraform Mars. Developing them would take enormous amounts of research and money, probably much more than possible in the near term. Although the Genesis device from “Star Trek III” could terraform a planet in a matter of minutes, terraforming Mars would take centuries or even millennia.

And there are a lot of ethical questions to resolve before people get started on turning Mars into another Earth. Is it right to make such drastic permanent changes to another planet?

If this all leaves you disappointed, don’t be. As scientists create innovations to terraform Mars, we’ll also use them to make life better on Earth. Remember the technology we’re developing to print 3D habitats on Mars? Right now, I’m part of a group of scientists and engineers employing that very same technology to print homes here on Earth – which will help address the world’s housing shortage.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

This image provided by NASA shows the InSight Mars lander in a selfie photo composite on April 24, 2022, the 1,211th Martian day, or sol, of the mission.
| Photo Credit: AP

An immense reservoir of liquid water may reside deep under the surface of Mars within fractured igneous rocks, holding enough to fill an ocean that would cover the entire surface of Earth’s planetary neighbor.

That is the conclusion of scientists based on seismic data obtained by NASA’s robotic InSight lander during a mission that helped decipher the interior of Mars. The water, located about 7.2 to 12.4 miles (11.5 to 20 km) below the Martian surface, potentially offers conditions favorable to sustain microbial life, either in the past or now, the researchers said.

“At these depths, the crust is warm enough for water to exist as a liquid. At more shallow depths, the water would be frozen as ice,” said planetary scientist Vashan Wright of the University of California, San Diego’s Scripps Institution of Oceanography, lead author of the study published on Monday in the journal Proceedings of the National Academy of Sciences.

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“On Earth, we find microbial life deep underground where rocks are saturated with water and there is an energy source,” added planetary scientist and study co-author Michael Manga of the University of California, Berkeley.

The InSight lander touched down in 2018 to study the deep interior of Mars, gathering data on the planet’s various layers, from its liquid metal core to its mantle and its crust. The InSight mission ended in 2022.

“InSight was able to measure the speed of seismic waves and how they change with depth. The speed of seismic waves depends on what the rock is made of, where it has cracks and what fills the cracks,” Mr. Wright said. “We combined the measured seismic wave speed, gravity measurements and rock physics models. The rock physics models are the same as the ones we use to measure properties of aquifers on Earth or map oil and gas resources underground.”

The data indicated the presence of this reservoir of liquid water within fractured igneous rocks – formed in the cooling and solidification of magma or lava – in the Martian crust, the planet’s outermost layer.

“A mid-crust whose rocks are cracked and filled with liquid water best explains both seismic and gravity data,” Mr. Wright said. “The water exists within fractures. If the InSight location is representative and you extract all the water from the fractures in the mid-crust, we estimate that the water would fill a 1-2 km deep (0.6-1.2 miles) ocean on Mars globally.”

The Martian surface is cold and desolate today but once was warm and wet. That changed more than 3 billion years ago. The study suggests that much of the water that had been on the Martian surface did not escape into space, but rather filtered down into the crust.

“Early Mars had liquid water on its surface in rivers, lakes and possibly oceans. The crust on Mars could also have been full of water from very early in its history, too,” Mr. Manga said. “On Earth, groundwater underground infiltrated from the surface, and we expect this to be similar to the history of water on Mars. This must have occurred during a time when the upper crust was warmer than it is today.”

Water would be a vital resource if humankind ever is to place astronauts on the Martian surface or establish some sort of long-term settlement. Mars harbors water in the form of ice at its polar regions and in its subsurface. But the depth of the apparent underground liquid water would make it difficult to access.

“Drilling to these depths is very challenging. Looking for places where geological activity expels this water, possibly the tectonically active Cerberus Fossae (a region in the northern hemisphere of Mars), is an alternative to looking for deep liquids,” Mr. Manga said, though he noted that concerns about protecting the Martian environment would need to be addressed.

Ground-penetrating radar on board NASA’s Mars Perseverance rover has confirmed that the Jezero Crater, formed by an ancient meteor impact just north of the Martian equator, once harboured a vast lake and river delta. Over eons, sediment deposition and erosion within the crater shaped the geologic formations visible on the surface today. The discovery of lake sediments reinforces the hope that traces of life might be found in soil and rock samples collected by Perseverance. The crater filled with water has layers of sediments deposited on the crater floor. The lake subsequently shrank and sediments carried by the river that fed it formed an enormous delta. As the lake dissipated over time, the sediments in the crater were eroded, forming the geologic features visible on the surface today. Perseverance’s soil and rock samples will be brought back to Earth by a future expedition and studied for evidence of past life. Between May and December 2022, Perseverance drove from the crater floor onto the delta, a vast expanse of three-billion-year-old sediments that, from orbit, resembles the river deltas on Earth.