What are the strongest signs of ancient life on Mars, scientists discuss

Planetary scientists weighed in on the dark-rimmed 'leopard spots' which are present in a rock on Mars. The rock was studied by the rover last year, and scientists believe that it could be the remains of Martian microbial activity.

Last year on July 18, Perseverance rover captured a stunning image of a rock nicknamed "Cheyava Falls". Large white calcium sulfate veins were seen on the rock.

Add WION as a Preferred Source

There were small irregular patches of material whose reddish colour suggests the presence of hematite. Notably, hematite is one of the minerals that gives Mars its distinctive rusty hue.

Scientists were intrigued by these small spots which were millimeter in size and irregularly shaped. The patches were surrounded by a thin ring of dark material, very much similar to spots on the leopard's body.

NASA last year said that the rover's analysis suggested that the rock possesses qualities that fit the definition of a possible indicator of ancient life that could possibly have been formed by life billions of years ago when the area being explored by the rover contained running water, the report added.

What do the experts say?

Joel Hurowitz, a geochemist at Stony Brook University in New York, told the conference that "chemical analysis using the rovers' instruments showed that the poppy seeds and the rims of the leopard spots are rich in iron and phosphorous. The centres of the leopard spots are rich in iron and sulphur". Such reactions are kicked off by microbes on Earth.

With poppy seeds, scientists refered to the dark peppery spots found on rock formed in the channel of an ancient river that once flowed into the lake in Jezero Crater. The crater held a lake that could have been conducive to life aeons ago.

"We should feel compelled to do a whole lot of laboratory, field and modelling studies to try to investigate features like this in more detail. And ultimately bring these samples back home so that we can reach a conclusion with regard to whether or not they were or were not formed by life," Hurowitz told the conference.

(With inputs from ageincies)