Written by Will Dunham
WASHINGTON (Archyde.com) – Core samples drilled into the surface of Mars by NASA’s Persevere rover have revealed the geology of a crater that scientists suspect may have harbored microbial life billions of years ago.
The samples obtained by the six-wheeled robotic rover, which is the size of a car, and which is stored for transport to Earth in the future for further study, are from four floors inside the Jezero Crater, which was formed by cooling molten material. The rocks have evidence of alteration through exposure to water, another sign that cold, dry Mars has long been warm and humid.
Scientists believe the rock, which formed about 3.5 billion years ago, may have been sediments formed as mud and sand deposited on the shores of the lake.
“In fact, we don’t have any evidence of sedimentary rocks where the probe has studied the crater floor, but we do know that the crater had a lake and must have been deposited,” said Kenneth, a geochemist at Caltech. These sediments must have eroded away.” Farley is the lead author of one of four studies published in the journal Science and Scientific Advances describing the geology of the crater.
Perseverance arrived on Mars in February 2021, and since then it has been actively working in Jezero crater, where scientists are researching whether Earth’s closest neighbors always have favorable conditions for life.
It collects rock samples the size of chalk in small tubes to be retrieved by a spacecraft in 2033 and returned to Earth for further study, including biosignatures – indicators of life.
Jezero Crater is 28 miles (45 km) wide and is located north of the Martian equator. The area appears to have been once submerged in water and home to a river delta, with river channels extending over the crater wall to form a large lake. Scientists think the crater may have harbored microbial life, with evidence likely in lake shores or coastal rocks.
Samples are currently being collected diligently in the delta region.
The igneous rocks of the crater were found interacting with water, forming new minerals and depositing salts, although apparently this water was in little or not very long quantities – groundwater. The researchers said the presence of water indicates that it may have been a habitable environment at the time.
“We have collected samples that will return to Earth, and they should provide important clues to the types of organisms that lived on the terrestrial rocks of the Jezero Crater when they came into contact with water,” said Yang Liu, a planetary sampling scientist at NASA. JPL and lead author of one of the studies.
Four samples were excavated from two areas, one in Sita and the other in Mas. Sita rock appears to have formed underground by the slow cooling of a thick plate of magma. Massive rocks may cool relatively quickly in the upper layer of subterranean magma or after an eruption of the volcanic surface. However, any rock layers that once covered these areas have been eroded by water or wind.
The Setah samples are coarse igneous rocks containing the mineral olivine, Liu said, noting that three Martian meteorites found on Earth have a similar composition.
Examination of samples taken from Earth can reveal when the rock formed and provide a definitive answer as to when liquid water existed on Mars. Liquid water is an essential element for life.
“When, and for how long, the climatic conditions that allowed liquid water to settle on Mars are of central importance to the big questions we’re trying to address through this mission and sample return — whether life has ever existed on Mars,” said Dr. David Schuster, a geochemist at Mars. University of California and co-author of the study, “When, Billions of Years Ago.”
(Reporting by Will Dunhamk; Editing by Rosalba O’Brien)