To the untrained eye, the Curiosity rover’s latest find might look pretty unremarkable.
But to scientists operating NASA’s Curiosity Rover, the dusty slab is a geological treasure trove, potentially revealing evidence that water once ran across the surface of the Red Planet.
Over the past few weeks, scientists have been analysing the slab’s cross-hatching, which is believed to be evidence of cracks in drying mud.
“Mud cracks are the most likely scenario here,” said Curiosity science team member Nathan Stein, a graduate student at Caltech in Pasadena, California, who led the investigation of the site nicknamed “Old Soaker”.
If the interpretation proves accurate, they would be the first evidence of mud cracks on Mars. The slab is believed to have formed in an ancient era when deposited sediments dried after wetter conditions.
In a blog post, NASA explained that the cracked layer formed more than three billion years ago, before being buried by layers of sediment and transforming into stratified rock. Wind has subsequently stripped away several layers.
It’s not the first time Curiosity has found evidence of water in the region. Old, lower-lying rock layers and in younger mudstone above Old Soaker signals that an ancient lake once covered the area.
“If these are indeed mud cracks, they fit well with the context of what we’re seeing in the section of Mount Sharp Curiosity has been climbing for many months,” said Curiosity Project Scientist Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Pasadena.
“The ancient lakes varied in depth and extent over time, and sometimes disappeared. We’re seeing more evidence of dry intervals between what had been mostly a record of long-lived lakes.”