The 24th sample taken by the six-wheeled scientist offers new clues about Jezero Crater and the lake it may have once held.

As of April 4, Perseverance has been active on Mars for 1,110 sols or three years, one month, and 17 days in Earth time since its landing. In that time, the lonely rover collected 24 samples, but the latest embodies exactly why NASA sent the six-wheeled scientist to the Red Planet.

The mission of the Mars 2020 Perseverance rover is to focus on surface-based studies of the Martian environment by seeking preserved signs of biosignatures in rock samples that formed in environments with conditions that may have been favorable to microbial life.

In its ongoing tenure, the isolated robot has tracked about the alien surface at various targets that hold the possibility of remnant life signs, such as ancient lake beds like the Jezero Crater.

While NASA confirmed the presence of water on Mars back in 2008, the next logical question was to determine if, at some point, the previously hydrated planet may in fact once have held life.

Now, analysis by instruments aboard Perseverance indicate that its latest core was awash in water for an extended period of time in the distant past, perhaps as part of an ancient Martian beach.

The 24th sample

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."

Like amateur archaeologists sleuthing through rivers for trilobites, ammonites, gastropods, or plant fossils to paint a picture of the rich and abundant life of a time before recorded history, NASA hopes to find similar signs of life, but perhaps on a much smaller scale.

The presence of specific minerals in the latest sample is considered promising for preserving a rich record of an ancient habitable environment on Mars. This should make the Martian beach sample a top priority for eventual transport back to Earth during the Mars Sample Return campaign.

Edge of the crater

While the sample was taken within Jezero Crater, the rover specifically targeted a unique formation along the banks of what is believed to be an ancient lake.

NASA/JPL-Caltech/ASU/MSSS

This mosaic shows a rock called "Bunsen Peak" where NASA's Perseverance Mars rover extracted its 21st rock core and abraded a circular patch to investigate the rock's composition.

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'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 the scientific instruments to investigate.

Before taking the sample, Perseverance scanned the rock using the rover's SuperCam spectrometers and X-ray spectrometer PIXL (Planetary Instrument for X-ray Lithochemistry). Afterward, the rover used the rotor on the end of its robotic arm to grind (or rather abrade) a portion of the surface, to which is scanned once more.

NASA/JPL-Caltech

Perseverance's CacheCam captured this image of the rover's latest cored sample – taken from an intriguing rock called "Bunsen Peak" – on March 11.

The results: Bunsen Peak looks to be composed of roughly 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.

Somewhat comparable to the dramatic scene of a mosquito trapped in amber that allowed the scientists in Jurassic Park to bring dinosaurs back to life. the silica, which is commonly found in nature as quartz, functions like a capsule frozen in time.

"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."

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."

Bright Angel and ascension

Presently, 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.

As the first rover mission designed to seek signs of past microbial life on an entirely different planet, the results have already proven exciting for confirmation. As with all things science, conjecture is fun, but without retrieving the samples and verifying whether or not life has been preserved, the first goal of the Mars Exploration Program is still considered incomplete.

However, if confirmed, the name Perseverance will mean much more than a steadfast robot 193.67 million miles away doing its job diligently, it will become a symbol that is best summarized by Dr. Ian Malcolm in the titular Jurassic dino flick – "life finds a way."