Scientists at NASA and Los Alamos National Laboratory said Tuesday at a meeting of the American Geophysical Union (AGU) that the Curiosity rover has detected boron for the first time on Mars. It indicates that the red planet’s groundwater was possibly suitable for hosting microbial life forms in the ancient past. Scientists believe that Mars was capable of supporting life for hundreds of millions of years in the ancient past.

Mars boron
Image source: Kevin M. Gill / Flickr

Groundwater on ancient Mars was liquid

Since landing in the Gale Crater on Mars in August 2012, the Curiosity rover has been studying different rocks over an elevation range of 200 meters. Boron is found abundantly in arid sites where water has evaporated away. The discovery of boron at Mount Sharp inside Gale Crater indicates that the ancient Martian groundwater was liquid and habitable.

John Grotzinger, a geologist at the California Institute of Technology and a Curiosity team member, said the red planet seems to have been favorable for life in ancient times. Curiosity’s observations have already revealed that the Gale Crater harbored a habitable lake and stream system billions of years ago.

Groundwater temperature would have been 0-60 degrees Celsius

Patrick Gasda of Los Alamos National Laboratory said if the boron detected in the calcium sulfate mineral veins of Mars is similar to the boron on Earth, the ancient Martian groundwater temperature would have been 0-60 degrees Celsius and neutral-to-alkaline pH. The pH, temperature, and dissolved mineral content all point to the groundwater being habitable for life as we know it.

The boron was identified by Curiosity’s Chemistry and Camera (ChemCam) instrument. What was the source of boron that groundwater left in the veins? Scientists believe that the drying out of a part of Gale lake led to a boron-containing deposit in an overlaying layer, where Curiosity is yet to reach. A small amount of boron from this layer might have been carried down by groundwater later into fractures in the rocks.

Curiosity encounters technical difficulties

As Curiosity climbs up the layered Martian mountain, the rock composition includes more clay and more boron. John Grotzinger said in a statement that boron and clay highlight the mobility of electrons and elements, and that’s “good for life.” The chemical complexity points to a “long, interactive history with water.” The more complex the chemistry, the better it is for habitability, said Grotzinger.

However, the Curiosity rover started acting weird recently when climbing up the Mount Sharp. NASA said that a part of the extendable arm kept getting jammed. The space agency has been running tests to narrow down the cause of the snag. After ruling out software and electrical problems, NASA engineers said it was due to a brake inside the motor that moves the extendable arm. The rover can’t move until the issue has been fixed.