NASA’s Perseverance rover has stumbled across a rather intriguing rock while driving west downslope towards lower “Witch Hazel Hill” on the edge of the Jezero Crater rim on Mars.
Over the last week, the Perseverance rover has moved down the Witch Hazel Hill area, towards an area named by the team as “Port Anson”. From orbit, NASA identified a series of light and dark-toned bands, and sent the rover to the boundary between two bands to investigate from a closer vantage point. At this divide, termed a “contact”, the rover encountered a variety of rocks which appear to have “originated from elsewhere” and have been transported to the area, known as “float rocks”, meaning that they are out of place with its surroundings.
One rock, which the team have named rather dramatically “Skull Hill”, stood out more than the others.
“This float rock uniquely contrasts the surrounding light-toned outcrop with its dark tone and angular surface, and it features a few pits in the rock,” Margaret Deahn, PhD Student at Purdue University, explained in a NASA blog. “If you look closely, you might even spot spherules within the surrounding regolith!”
There are a few options for how the rock got there. One is that it is in fact a meteorite, deposited onto the planet’s surface. Meteorites found by the Curiosity rover in Gale crater have similar appearances to Skull Hill.
Meteorite found in Gale crater on Mars.
Image credit: NASA/JPL-Caltech/MSSS
However, looks can be deceiving. The meteorites found in Gale crater were found to contain large amounts of iron and nickel, but analysis of nearby rocks on Witch Hazel Hill suggest that they are not of meteoric origin.
“Alternatively, ‘Skull Hill’ could be an igneous rock eroded from a nearby outcrop or ejected from an impact crater,” Deahn continues. “On Earth and Mars, iron and magnesium are some of the main contributors to igneous rocks, which form from the cooling of magma or lava. These rocks can include dark-colored minerals such as olivine, pyroxene, amphibole, and biotite. Luckily for us, the rover has instruments that can measure the chemical composition of rocks on Mars.”
The Perseverance team will continue to study the rock, and others like it, hopefully providing answers as to how the float rock got there, as well as what’s up with those unusual spherules identified there last month.
Source Link: NASA Finds "Skull Hill" Rock On Mars, Believes It "Originated From Elsewhere"
