Nasa’s Curiosity rover discovery: evidence of life on Mars may have been erased.
Evidence of life on Mars may have been erased. A new Nasa study says so. The Curiosity rover made a surprising discovery while studying clay-rich sedimentary rocks right around its landing site in Gale Crater, a former lake created by an asteroid’s fall on the Red Planet about 3.6 billion years ago. Usually, clay is a good indicator of life forms because it is created when rocky minerals decay and rot after contact with water. It is also an excellent material for preserving microbial fossils. But analysis of one sedimentary rock sample contained only half the expected amount of clay minerals.
Curiosity’s discovery of evidence of life that may have been erased
Nasa’s rover took two samples of clay-containing rocks from the dried-up lake bed, dated 3.5 billion years ago. Researchers found that one piece contained only half the expected amount of clay minerals, while there was a higher amount of iron oxides, the compounds that give Mars its rust color.
The team of scientists therefore believes that the disappearance of the clay was caused by super-salty water cleaning up the area. “We thought that once formed, these layers of clay minerals would stay that way,” said the study’s lead author Tom Bristow. “But later brines destroyed these clay minerals in places.” Curiosity then completed its analysis by drilling into the Martian rock layers before using the chemistry and mineralogy instrument, known as CheMin, to observe the samples.
According to the study authors, the process of chemical transformation in the sediments is called diagenesis and may have created new life on Mars, erasing some of the evidence of old life forms on its surface. Because of this, even though the old evidence may have been erased, the chemical conditions caused by the influx of salt water may have allowed other beings to be born in its place.
The research conducted by Curiosity not only revealed how the Martian climate has changed, but also helped Perseverance determine which soil samples to collect to increase the chances of finding life forms, and researchers are excited about the recent discovery because they believe it can help them understand how the Red Planet has transformed. Recently, Always Curiosity also captured images of spectacular iridescent clouds on Mars.
Stefania Bernardini