In a finding that suggests “considerable water activity” on Mars, NASA says its Curiosity rover has found very high concentrations of silica on the red planet. The agency says it also found “a mineral named tridymite, rare on Earth and never seen before on Mars.”
The discoveries took place on Mount Sharp, where Curiosity drilled into a rock called “Buckskin” to find the tridymite, and where it used its “ChemCam” laser to measure high silica levels. The odd findings led researchers to take the rare step of ordering Curiosity to retrace its path to learn more.
Explanations for the high silica levels “all require considerable water activity,” says Jens Frydenvang of Los Alamos National Laboratory and the University of Copenhagen. He adds, “and on Earth high silica deposits are often associated with environments that provide excellent support for microbial life.” […]