The 21st rock core captured by NASA’s Perseverance has a composition that would make it good at trapping and preserving signs of microbial life, if any was once present. The sample – shown being taken here – was cored from “Bunsen Peak” on March 11, the 1,088th Martian day, or sol, of the mission. NASA/JPL-Caltech
The 24th sample taken by the six-wheeled scientist offers new clues about
Jezero Crater and the lake it may have once held.
Analysis by instruments aboard
NASA’s Perseverance Mars rover indicate that the latest rock core taken by the
rover was awash in water for an extended period of time in the distant past,
perhaps as part of an ancient Martian beach. Collected on March 11, the sample
is the rover’s 24th – a tally that includes 21 sample tubes filled
with rock cores, two filled with regolith (broken rock and dust), and one with
Martian atmosphere.
“To put it simply, this is the kind
of rock we had hoped to find when we decided to investigate Jezero Crater,”
said Ken Farley, project scientist for Perseverance at Caltech in Pasadena,
California. “Nearly all the minerals in the rock we just sampled were made in
water; on Earth, water-deposited minerals are often good at trapping and
preserving ancient organic material and biosignatures. The rock can even tell
us about Mars climate conditions that were present when it was formed.”
The presence of these specific
minerals is considered promising for preserving a rich record of an ancient
habitable environment on Mars. Such collections of minerals are important for
guiding scientists to the most valuable samples for eventual return to Earth
with the Mars Sample Return campaign.
Edge of the
Crater’s Rim
Nicknamed “Bunsen Peak” for the Yellowstone National Park landmark, the rock – about 5.6 feet wide and 3.3 feet high (1.7 meters by 1 meter) – intrigued Perseverance scientists because the outcrop stands tall amid the surrounding terrain and has an interesting texture on one of its faces. They were also interested in Bunsen Peak’s vertical rockface, which offers a nice cross-section of the rock and, because it’s not flat-lying, is less dusty and therefore easier for science instruments to investigate.
Meet the 24th Martian sample collected by NASA’s
Mars Perseverance rover – “Comet Geyser,” a sample taken from a region of
Jezero Crater that is especially rich in carbonate, a mineral linked to
habitability.
Before taking the sample,
Perseverance scanned the rock using the rover’s SuperCam spectrometers and the X-ray spectrometer PIXL, short for Planetary Instrument for X-ray Lithochemistry. Then the rover
used the rotor on the end of its robotic arm to grind (or abrade) a portion of
the surface and scanned the rock again. The results: Bunsen Peak looks to be
composed of about 75% carbonate grains cemented together by almost pure silica.
“The silica and parts of the
carbonate appear microcrystalline, which makes them extremely good at trapping
and preserving signs of microbial life that might have once lived in this
environment,” said Sandra Siljeström, a Perseverance scientist from the Research
Institutes of Sweden (RISE) in Stockholm. “That makes this sample great for
biosignature studies if returned to Earth. Additionally, the sample might be
one of the older cores collected so far by Perseverance, and that is important
because Mars was at its most habitable early in its history.” A potential
biosignature is a substance or structure that could be evidence of past life
but may also have been produced without the presence of life.
The Bunsen Peak sample is the third that Perseverance has collected while exploring the “Margin Unit,” a geologic area that hugs the inner edge of Jezero Crater’s rim.
“We’re still exploring the margin and gathering data, but results so far
may support our hypothesis that the rocks here formed along the shores of an
ancient lake,” said Briony Horgan, a Perseverance scientist from Purdue
University, in West Lafayette, Indiana. “The science team is also considering
other ideas for the origin of the Margin Unit, as there are other ways to form
carbonate and silica. But no matter how this rock formed, it is really exciting
to get a sample.”
The rover is working its way toward
the westernmost portion of the Margin Unit. At the base of Jezero Crater’s rim,
a location nicknamed “Bright Angel” is of interest to the science team because
it may offer the first encounter with the much older rocks that make up the
crater rim. Once it’s done exploring Bright Angel, Perseverance will begin an
ascent of several months to the rim’s top.
More About the
Mission
A key objective for Perseverance’s
mission on Mars is astrobiology, including caching samples that may contain 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.
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.
NASA’s Jet Propulsion Laboratory,
which is managed for the agency by Caltech, built and manages operations of the
Perseverance rover.
For more about Perseverance: https://mars.nasa.gov/mars2020/
Source: Rock Sampled by NASA’s Perseverance Embodies Why Rover Came to Mars - NASA
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