NASA’s Curiosity rover has just reported a deluge of interesting chemicals on the slopes of Mount Sharp on Mars, providing a lot more clues about the warm, water-rich environment it used to have.

The plutonium-powered rover has been making its way up the mountain since 2014, and has studied many different environments during its climb. It is currently exploring an area that used to be wet and that accumulated sediments over time. Among these, Curiosity observed hematite, clay minerals, and, for the first time, Boron.

"There is so much variability in the composition at different elevations, we've hit a jackpot," said John Grotzinger, of Caltech in Pasadena, California, in a statement. 

"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."

There’s still no irrefutable evidence for life on Mars, but our four-decade-long study of the Red Planet has uncovered a complex geology both in the past and in the present. As the rover climbs up Mount Sharp it is exploring younger layers and never seen before features become suddenly apparent.

"No prior mission has detected boron on Mars," added Patrick Gasda of the US Department of Energy's Los Alamos National Laboratory, Los Alamos, New Mexico. "We're seeing a sharp increase in boron in vein targets inspected in the past several months.”

^{Curiosity discovery of Boron. NASA/JPL-Caltech/MSSS/LANL/CNES-IRAP/William Rapin}

The discovery of boron was a bit of a curveball for scientists. It is only a minute quantity, one-tenth of 1 percent of the rock composition, but it’s not clear how it got there. Scientists believe it was either the evaporation of a lake or maybe changes in the chemistry of the clay deposit. The latter idea is consistent with the deposit of hematite found in the area.

"Variations in these minerals and elements indicate a dynamic system. They interact with groundwater as well as surface water. The water influences the chemistry of the clays, but the composition of the water also changes," Grotzinger added.

“We are seeing chemical complexity indicating a long, interactive history with the water. The more complicated the chemistry is, the better it is for habitability. The boron, hematite, and clay minerals underline the mobility of elements and electrons, and that is good for life."

It will be interesting to see if the higher ground continues to show this increase in chemicals.