Red Planet Revelations: NASA’s Perseverance Rover Probes Secrets of Ancient Martian Lake

Now at 1,000 days on MarsMars is the second smallest planet in our solar system and the fourth planet from the sun. It is a dusty, cold, desert world with a very thin atmosphere. Iron oxide is prevalent in Mars' surface resulting in its reddish color and its nickname "The Red Planet." Mars' name comes from the Roman god of war.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>Mars, the mission has traversed an ancient river and lake system, collecting valuable samples along the way.

Marking its 1,000th Martian day on the Red Planet, NASAEstablished in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the United States Federal Government that succeeded the National Advisory Committee for Aeronautics (NACA). It is responsible for the civilian space program, as well as aeronautics and aerospace research. Its vision is "To discover and expand knowledge for the benefit of humanity." Its core values are "safety, integrity, teamwork, excellence, and inclusion." NASA conducts research, develops technology and launches missions to explore and study Earth, the solar system, and the universe beyond. It also works to advance the state of knowledge in a wide range of scientific fields, including Earth and space science, planetary science, astrophysics, and heliophysics, and it collaborates with private companies and international partners to achieve its goals.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>NASA’s Perseverance rover recently completed its exploration of the ancient river delta that holds evidence of a lake that filled Jezero Crater billions of years ago. The six-wheeled scientist has to date collected a total of 23 samples, revealing the geologic history of this region of Mars in the process.

Vital Discoveries in Martian Samples

One sample called “Lefroy Bay” contains a large quantity of fine-grained silica, a material known to preserve ancient fossils on Earth. Another, “Otis Peak,” holds a significant amount of phosphate, which is often associated with life as we know it. Both of these samples are also rich in carbonate, which can preserve a record of the environmental conditions from when the rock was formed.

The discoveries were shared Tuesday, December 12, at the American Geophysical Union fall meeting in San Francisco.

This 360-degree mosaic from the “Airey Hill” location inside Jezero Crater was generated using 993 individual images taken by the Perseverance Mars rover’s Mastcam-Z from November 3-6. The rover remained parked at Airey Hill for several weeks during solar conjunction. Credit: NASA/JPL-Caltech/ASU/MSSS

Jezero Crater’s Geological History

“We picked Jezero Crater as a landing site because orbital imagery showed a delta – clear evidence that a large lake once filled the crater. A lake is a potentially habitable environment, and delta rocks are a great environment for entombing signs of ancient life as fossils in the geologic record,” said Perseverance’s project scientist, Ken Farley of Caltech. “After thorough exploration, we’ve pieced together the crater’s geologic history, charting its lake and river phase from beginning to end.”

Jezero formed from an asteroid impact almost 4 billion years ago. After Perseverance landed in February 2021, the mission team discovered the crater floor is made of igneous rock formed from magma underground or from volcanic activity at the surface. They have since found sandstone and mudstone, signaling the arrival of the first river in the crater hundreds of millions of years later. Above these rocks are salt-rich mudstones, signaling the presence of a shallow lake experiencing evaporation. The team thinks the lake eventually grew as wide as 22 miles (35 kilometers) in diameter and as deep as 100 feet (30 meters).

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This animated artist’s concept depicts water breaking through the rim of Mars’ Jezero Crater, which NASA’s Perseverance rover is now exploring. Water entered the crater billions of years ago, forming a lake, delta, and rivers before the Red Planet dried up. Credit: NASA/JPLThe Jet Propulsion Laboratory (JPL) is a federally funded research and development center that was established in 1936. It is owned by NASA and managed by the California Institute of Technology (Caltech). The laboratory's primary function is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating NASA's Deep Space Network. JPL implements programs in planetary exploration, Earth science, space-based astronomy and technology development, while applying its capabilities to technical and scientific problems of national significance.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>JPL-Caltech

Later, fast-flowing water carried in boulders from outside Jezero, distributing them atop of the delta and elsewhere in the crater.

“We were able to see a broad outline of these chapters in Jezero’s history in orbital images, but it required getting up close with Perseverance to really understand the timeline in detail,” said Libby Ives, a postdoctoral fellow at NASA’s Jet Propulsion Laboratory in Southern California, which manages the mission.

Enticing Samples

The samples Perseverance gathers are about as big as a piece of classroom chalk and are stored in special metal tubes as part of the Mars Sample Return campaign, a joint effort by NASA and ESA (European Space AgencyThe European Space Agency (ESA) is an intergovernmental organization dedicated to the exploration and study of space. ESA was established in 1975 and has 22 member states, with its headquarters located in Paris, France. ESA is responsible for the development and coordination of Europe's space activities, including the design, construction, and launch of spacecraft and satellites for scientific research and Earth observation. Some of ESA's flagship missions have included the Rosetta mission to study a comet, the Gaia mission to create a 3D map of the Milky Way, and the ExoMars mission to search for evidence of past or present life on Mars.” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>European Space Agency). Bringing the tubes to Earth would enable scientists to study the samples with powerful lab equipment too large to take to Mars.

To decide which samples to collect, Perseverance first uses an abrasion tool to wear away a patch of a prospective rock and then studies the rock’s chemistry using precision science instruments, including the JPL-built Planetary Instrument for X-ray Lithochemistry, or PIXL.

This image of Mars’ Jezero Crater is overlaid with mineral data detected from orbit. The green color represents carbonates – minerals that form in watery environments with conditions that might be favorable for preserving signs of ancient life. NASA’s Perseverance is currently exploring the green area above Jezero’s fan (center). Credit: NASA/JPL-Caltech/MSSS/JHU-APL

At a target the team calls “Bills Bay,” PIXL spotted carbonates – minerals that form in watery environments with conditions that might be favorable for preserving organic molecules. (Organic molecules form by both geological and biological processes.) These rocks were also abundant with silica, a material that’s excellent at preserving organic molecules, including those related to life.

“On Earth, this fine-grained silica is what you often find in a location that was once sandy,” said JPL’s Morgan Cable, the deputy principal investigator of PIXL. “It’s the kind of environment where, on Earth, the remains of ancient life could be preserved and found later.”

Analyzing this abraded rock patch dubbed “Bills Bay,” the PIXL instrument on NASA’s Perseverance Mars rover found it rich in carbonates (purple) and silica (green), both of which are good at preserving signs of ancient life. The image is overlaid with the instrument’s chemical data. Credit: NASA/JPL-Caltech/MSSS

Perseverance’s instruments are capable of detecting both microscopic, fossil-like structures and chemical changes that may have been left by ancient microbes, but they have yet to see evidence for either.

At another target PIXL examined, called “Ouzel Falls,” the instrument detected the presence of iron associated with phosphate. Phosphate is a component of DNADNA, or deoxyribonucleic acid, is a molecule composed of two long strands of nucleotides that coil around each other to form a double helix. It is the hereditary material in humans and almost all other organisms that carries genetic instructions for development, functioning, growth, and reproduction. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).” data-gt-translate-attributes=”[{“attribute”:”data-cmtooltip”, “format”:”html”}]” tabindex=”0″ role=”link”>DNA and the cell membranes of all known terrestrial life and is part of a molecule that helps cells carry energy.

After assessing PIXL’s findings on each of these abrasion patches, the team sent up commands for the rover to collect rock cores close by: Lefroy Bay was collected next to Bills Bay, and Otis Peak at Ouzel Falls.

PIXL, one of the instruments aboard NASA’s Perseverance Mars rover, analyzed the chemical makeup of an area of abraded rock dubbed “Ouzel Falls,” finding it rich in minerals containing phosphate, a material found in the DNA and cell membranes of all known life. Credit: NASA/JPL-Caltech/MSSS

“We have ideal conditions for finding signs of ancient life where we find carbonates and phosphates, which point to a watery, habitable environment, as well as silica, which is great at preservation,” Cable said.

Perseverance’s work is, of course, far from done. The mission’s ongoing fourth science campaign will explore Jezero Crater’s margin, near the canyon entrance where a river once flooded the crater floor. Rich carbonate deposits have been spotted along the margin, which stands out in orbital images like a ring within a bathtub.

More About the Mission

A key objective for Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith (broken rock and dust).

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

JPL, which is managed for NASA by Caltech in Pasadena, California, built and manages operations of the Perseverance rover.