Martian mineral found in Antarctic ice

Scientists boring into ice have unearthed a mineral that’s rarely seen on Earth but found in abundance on Mars. The yellow-brown mineral, jarosite, requires both water and acidic conditions to form – environments that are hard to find now on the Red Planet. After the Opportunity rover first discovered jarosite on Mars in 2004, the mineral turned up in several Martian locations, leaving scientists wondering how it had become so common.

Some theorised that when ice covered the planet billions of years ago, dust containing the required minerals – iron, sulphate and potassium – may have been trapped inside. “Mars is such a dusty place – everything is covered in dust,” said Giovanni Baccolo, a geologist at the University of Milan-Bicocca. But while ice could have provided the wet environment needed for acidic dust to transform into jarosite, scientists have never actually seen dust and ice chemically reacting to form the mineral. But the discovery of jarosite particles locked in Antarctica’s ice may support the theory.

Slabs of jarosite may have formed on Mars because the Red Planet is far dustier than Antarctica, providing more raw material to form jarosite.