Written by Melissa Rice, Professor of Planetary Science at Western Washington College
Following a brief break for the July 4th vacation, Perseverance drove westward to a website referred to as “Westport,” the place the clay-bearing “Krokodillen” unit meets an olivine-bearing rock formation. It’s potential that the olivine-rich rocks are an intrusive igneous unit, which means they may have shaped when molten magma from deep inside Mars acquired pushed upwards and cooled below the floor. If that’s the case, Westport might protect a dramatic second in Mars’ historical past when sizzling, molten materials intruded into current rock formations.
These intrusive processes are frequent on Earth, and the warmth of the intruding magma can basically alter the encircling geology via a course of referred to as “contact metamorphism.” The warmth from the intrusion will “bake” close by rocks, creating new minerals and doubtlessly new environments for microbial life. Conversely, the intrusive rocks get quickly “chilled” the place they meet preexisting strong rock formations.
At Westport, Perseverance is in search of proof that the Krokodillen rocks on the contact had been baked, and that the olivine-bearing rocks on the contact had been chilled. Pictures from the Mastcam-Z instrument reveal that the contact is affected by intriguing darkish, rubbly rocks alongside lighter-toned, clean boulders. Each rock sorts are proving difficult to review.
The darkish fragments are too small and tough for Perseverance’s commonplace abrasion methods, however the rover cleared off the floor of a rock referred to as “Holyrood Bay” with its fuel Mud Elimination Instrument (gDRT). Perseverance additionally tried to abrade a close-by boulder named “Drake’s Level,” however the rock shifted to the aspect, inflicting the abrasion to cease brief. The science questions listed here are compelling sufficient, nonetheless, that Perseverance will preserve attempting to look throughout the rocks at this essential boundary.