Mars’s Jezero Crater is proving to be a treasure trove for scientists, offering a variety of promising geological samples that may hold clues to the Red Planet’s past.
With help from NASA’s Perseverance rover, researchers are now analyzing these materials to better understand Mars’s evolution and determine whether it was — or perhaps still is — habitable for certain extremophiles.
Driven by the potential importance of what may be hidden within Jezero Crater, NASA has accelerated its science collection efforts to the highest pace since Perseverance landed four years ago.
Fast-paced Collection Efforts
Since January, Perseverance has ramped up its mission at Jezero Crater following a three-month climb to the rim, completed in December. The current focus is “Witch Hazel Hill,” a 445-foot-tall slope notable for its remarkable diversity of rock formations. From this vantage point, the rover cored five rocks and sealed three samples in tubes. It also conducted extensive optical and laser analysis — observing seven rocks in detail and using lasers on 83 others.
“During previous science campaigns in Jezero, it could take several months to find a rock that was significantly different from the last rock we sampled and scientifically unique enough for sampling,” said Perseverance’s project scientist, Katie Stack Morgan of NASA’s Jet Propulsion Laboratory in Southern California. “But up here on the crater rim, there are new and intriguing rocks everywhere the rover turns. It has been all we had hoped for and more.”
Erupting from Beneath Mars
Jezero Crater’s scientific richness stems from the massive impact that formed it, which likely dislodged rocks from deep beneath the Martian surface. Subsequent, smaller impacts may have continued exposing these ancient rocks. Their varied origins are reflected in contrasting features — for instance, a rock that shows clear signs of water alteration lies near another that appears to have experienced little to no water exposure.
One of the first samples collected during this campaign, nicknamed “Silver Mountain,” was retrieved on January 28 from a rock dubbed “Shallow Bay.” Researchers believe this rock may have recrystallized after an ancient impact event, making the already 3.9-billion-year-old specimen even more compelling.
Volcanic Clues and Fragile Finds
Just 360 feet from Shallow Bay, the rover encountered an outcrop of igneous rock — formed from volcanic activity or magma — which can offer precise information about the conditions under which it formed. However, attempts to core the fragile igneous rocks failed, as they crumbled during the drilling process.
Tablelands and Martian Water
Another significant find lies 520 feet from the igneous outcrop: a boulder named “Tablelands,” composed of serpentine minerals. These minerals form when iron- and magnesium-rich rocks react with water. The process, known as serpentinization, alters the rock’s structure and releases byproducts like hydrogen gas as the rock expands and fractures.
On Earth, serpentine rocks are associated with microbial life. When hydrogen from serpentinization combines with atmospheric carbon dioxide, it can create methane — a potential food source for microbes. While not definitive evidence of life on Mars, Tablelands adds to the growing list of signs suggesting the planet was once habitable.
Sealing the Tablelands sample, however, proved to be one of the mission’s toughest challenges due to interference from powdered rock at the top of the tube.
“This happened once before, when there was enough powdered rock at the top of the tube that it interfered with getting a perfect seal,” said Kyle Kaplan, a robotics engineer at JPL. “For Tablelands, we pulled out all the stops. Over 13 sols,” or Martian days, “we used a tool to brush out the top of the tube 33 times and made eight sealing attempts. We even flicked it a second time.”
Roaming Mars
Perseverance’s journey is far from over. Fortunately, sealing the next sample — dubbed “Main River” — went smoothly, and the resulting specimen revealed alternating light and dark bands, unlike anything the team had previously encountered. The rover’s exploration of Witch Hazel Hill continues.
“The last four months have been a whirlwind for the science team, and we still feel that Witch Hazel Hill has more to tell us,” said Stack. “We’ll use all the rover data gathered recently to decide if and where to collect the next sample from the crater rim. Crater rims — you gotta love ‘em.”
Ryan Whalen covers science and technology for The Debrief. He holds an MA in History and a Master of Library and Information Science with a certificate in Data Science. He can be contacted at ryan@thedebrief.org, and follow him on Twitter @mdntwvlf.