• After Curiosity drove over a rock, cracking it open, NASA scientists discovered sulphur.
• Scientists aren’t sure why this region of Mars contains sulphur but it will begin trying to form an explanation.
• Curiosity has been exploring Mars for the better part of a decade and this is the first time it has discovered sulphur.

Since late 2012, NASA’s Curiosity rover has been plodding along the Martian surface. Over that decade, the rover has helped make many discoveries and earlier this year it made another, entirely by accident.

On 30th May, the rover drove over a rock and seemingly because of its sheer weight, the rock cracked. Not a discovery in and of itself, but the cracked rock revealed yellow sulphur crystals.

While NASA says the rover was exploring a region of Mars known to contain sulphates, it wasn’t expecting to find pure sulphur.

“Finding a field of stones made of pure sulfur is like finding an oasis in the desert,” said Curiosity’s project scientist, Ashwin Vasavada of NASA’s Jet Propulsion Laboratory in Southern California. “It shouldn’t be there, so now we have to explain it. Discovering strange and unexpected things is what makes planetary exploration so exciting.”

The rover is currently winding its way through a 5km tall groove in the Gediz Vallis channel as it ascends Mount Sharp. Each layer in the mountain represents a different period of Martian history, which will hopefully give insight into whether Mars could ever have sustained life.

Since it began exploring the area, scientists have studied whether ancient floods or landslides shaped the channel’s floor. The layout of debris suggests that violent water flows shaped the landscape.

The rocks containing sulphur are too small and brittle to drill but a larger rock dubbed Mammoth Lakes was able to be drilled, Curiosity’s 41st drill since landing on the planet.

A sample has been collected and scientists will now analyse the materials in the sample.

“Curiosity has since driven away from Mammoth Lakes and is now off to see what other surprises are waiting to be discovered within the channel,” NASA said.

While we know a lot about Mars given the popularity of the planet, much is still yet to be discovered, as this news highlights. Perhaps then we should approach colonisation efforts with a bit more caution than we have been.