Opportunity rover investigates unusual rock ‘veins’ on Mars

View of Homestake vein, in colour. Credit: NASA/JPL/Stuart Atkinson

Continuing its exploration of Endeavour crater, the Opportunity rover has come across something very interesting, which has the rover team members and others rather excited; unusual “veins” of exposed rock that are significantly brighter than the surrounding soil or other rocks. They are narrow and linear, sort of snake-like in appearance but often broken into segments, almost like bricks. This is the first time they have been found by either rover, or any other rover or lander in the past. What are they?

According to Steve Squyres, principal investigator for the Mars Exploration Rovers Mission, “These are different than anything from anything we’ve ever seen with either rover, a completely new thing on Mars, never seen anywhere. And we’re pretty charged up about it.”

One of the first "veins" (circled) seen by Opportunity as it approached Endeavour crater. Credit: NASA/JPL/Stuart Atkinson

Stuart Atkinson has been providing excellent coverage of them on his blog The Road to Endeavour, with numerous images, including the best montage images I’ve seen so far, where some of the smaller individual images sent back by Opportunity are stitched together to make a larger, more complete photo.

Opportunity is still examining one of these veins right now, called Homestake (not sure why it was named that), but there is no more information yet on what it is composed of. Are they related to the clay minerals that Opportunity is searching for, and known to be in this area? Why are they so bright? The material seems to be quite hard, with many fine linear “scratches” on its surface.

View of Homestake vein, in colour. Credit: NASA/JPL/Stuart Atkinson
Microscopic Imager view of portion of Homestake vein. Credit: NASA/JPL/Stuart Atkinson

A larger version of the Microscopic Imager image is here.

The general feeling right now is that these veins are probably water-related, formed by hydrothermal processes a long time ago. They resemble magnesite (magnesium carbonate) veins on Earth, which can form via the carbonation of olivine in the presence of water and carbon dioxide. Whatever they actually are, the analysis being done should turn out to be quite interesting, so stay tuned!