Boron, a chemical signature of evaporated water, has recently been discovered on the surface of Mars, and this suggests that the Red Planet has the potential for long-term habitable groundwater in the ancient past.

"No prior mission to Mars has found boron," said Patrick Gasda, a postdoctoral researcher at Los Alamos National Laboratory in a press conference, as posted in Science Daily.

"If the boron that we found in calcium sulfate mineral veins on Mars is similar to what we see on Earth, it would indicate that the groundwater of ancient Mars that formed these veins would have been 0-60 degrees Celsius [32-140 degrees Fahrenheit] and neutral-to-alkaline pH."

As reported by NASA, Curiosity found the boron on its trek up the slopes of Mount Sharp, within the Gale Crater. It identified the mineral using rover's Chemistry and Camera (ChemCam).

"The ChemCam instrument provides quantitative elemental compositions of targets in Gale Crater using laser-induced breakdown spectroscopy," the scientists at Los Alamos National Laboratory explained.

Meanwhile, further analysis is needed to figure out how Boron ended up on Mars surface. Science Alert said the scientists are currently working on two hypotheses:

First, drying out of the Gale lake resulted in a vast boron-containing deposit in an overlying layer that Curiosity hasn't yet reached, or maybe shifts chemistry of clay-bearing deposits and groundwater changed how boron was transported around local sediments.

The researchers expect more clues to be uncovered as Curiosity continues its trek. And while nothing is so certain yet, they said that the fact that they have seen evidence of changing rock/mineral composition, shifting lakes and changing environments, is already exciting.

"There is so much variability in the composition at different elevations, we've hit a jackpot," John Grotzinger from Caltech, one of the members of the team, said in a conference.

"A sedimentary basin such as this is a chemical reactor. Elements get rearranged. New minerals form and old ones dissolve. Electrons get redistributed. On Earth, these reactions support life."

The scientists reported the findings on December 13 at the American Geophysical Union's fall meeting.