NASA’s aging Opportunity rover on Mars has just made what may be one of its most significant discoveries to date.
The nine-year-old robot has identified rock laden with what scientists believe to be clay minerals. Their presence is an indication that the rock, dubbed Esperance, has been altered at some point in the past through prolonged contact with water.
Opportunity has seen a clay-bearing outcrop before but scientists say this is by far the best example to date.
“If you look at all of the water-related discoveries that have been made by Opportunity, the vast majority of them point to water that was a very low pH — it was acid,” said professor Steve Squyres, the rover’s principal investigator. “Clay minerals only tend to form at a more neutral pH. This is water you could drink. This is water that was much more favourable for things like pre-biotic chemistry — the kind of chemistry that could lead to the origin of life.”
These results complement nicely those of NASA’s newer rover Curiosity, which has also identified clays at its landing site almost halfway around the planet’s equator. The old robot made its find at a location called Cape York, which is located on the rim of a 22-km-wide crater known as Endurance. There is an expectation that Opportunity will find a deeper stack of rocks at a new location to follow up the Esperance water story.
— © BBC News/Distributed by the New York Times Syndicate