Scientists have discovered a mineral in Antarctic ice that is rarely found on Earth, but is abundant on Mars. It’s called jarosite and it is made up of potassium, sulfate, and iron.
The yellow-brown mineral requires water and acid to form. At the moment, these conditions are difficult to find on the red planet, but after the Opportunity rover first discovered jarosite in 2004, the mineral was found in several places on the planet. Scientists do not yet know how it was formed there in such large quantities.
On Earth, jarosite is a rare mineral that is present in mining waste exposed to air and rain. The study’s author, Giovanni Baccolo, a geologist at the University of Milan-Bicocca, and his colleagues never expected to find the mineral in Antarctica, he told Science.
However, by extracting a 1,600-meter-long ice core from the ground, they found traces of jarosite. They were smaller than grains of sand and buried deep in the ice.
After examining the particles with an electron microscope, the team deduced that the jarosite had formed in muddy pockets within the ice. This finding suggests that the mineral was formed in the same way on Mars, although on the red planet jarosite appears in meter-thick deposits and not as a few scattered grains, says Megan Elwood Madden, a geochemist at the University of Oklahoma that he did not participate in the investigation.
These thick plates of jarosite may have formed on Mars because the planet has infinitely more dust than Antarctica, and jarosite is formed from dust, Baccolo noted.
“This is just the first step in relating the deep ice of Antarctica to the Martian environment,” she added.