A strange and solitary striped rock, different from everything around it, has absolutely excited the scientists of the Perseverance rover, which for three years has been traveling the surface of the Jazero crater, on Mars. And, in the almost 30 years that NASA has been exploring the red planet with robotic vehicles (the first was Sojourner in 1997), no one had seen anything like it.
The initial data collected by the rover suggests that the rock, which researchers have named ‘Freya’s Castle’, could have a volcanic origin, and that it could come from an outcrop of this strange material in an as yet unexplored area of the Jezero crater.
Of course, the rock is very different from any other previously observed on Mars. And there, in the crater and surrounded by hundreds of other ‘normal’ stones, it seems out of place. However, despite its obvious interest, Perseverance could not stay with it for too long to examine it thoroughly before continuing its programmed path along the inner wall of the crater.
First data
The strange rock was detected while the rover was taking photographs with its Mastcam Z instrument a couple of weeks ago, on September 13. The stone measures about 20 cm wide, and the first multispectral observations have already provided clues to its possible origin.
“What we know about its chemical composition is little,” explains Athanasios Klidaras, of Purdue University, in a NASA statement– but the first interpretations are that gneous and/or metamorphic processes could have created its stripes.
A volcanic or metamorphic origin (in which one type of rock transforms into another, usually under very high temperatures or pressures) can explain the origin of the streaks. But it does not solve the mystery of how Freya’s Castle could get to the place where Perseverance found it. One possibility, researchers say, is that it rolled from a similar rock outcrop higher up the slopes.
That possibility – writes Klidaras – excites us and we hope that, as we move uphill, Perseverance can find an outcrop of this new type of rock to obtain more detailed measurements.
It is not uncommon to find strange rocks on the slope of the crater’s inner wall. In a way, it’s something the mission scientists have been waiting for for a long time. Only so far they haven’t had any luck.