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 web site known as “Westport,” the place the clay-bearing “Krokodillen” unit meets an olivine-bearing rock formation. It’s attainable that the olivine-rich rocks are an intrusive igneous unit, that means they might have fashioned when molten magma from deep inside Mars received pushed upwards and cooled underneath the floor. If that’s the case, Westport may protect a dramatic second in Mars’ historical past when scorching, molten materials intruded into present rock formations.
These intrusive processes are frequent on Earth, and the warmth of the intruding magma can essentially alter the encompassing geology by a course of known 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 stable rock formations.
At Westport, Perseverance is on the lookout for 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 suffering from intriguing darkish, rubbly rocks alongside lighter-toned, easy boulders. Each rock varieties are proving difficult to check.
The darkish fragments are too small and tough for Perseverance’s normal abrasion strategies, however the rover cleared off the floor of a rock known as “Holyrood Bay” with its gasoline Mud Removing Device (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, nevertheless, that Perseverance will hold attempting to look inside the rocks at this essential boundary.
