Barnacle Bill

Barnacle Bill is an andesite-type rock.

Matt Golombek video
Matt Golombek audio --

We had the choice of going down one of two ramps and one ramp, as you're aware, was sticking straight up. We didn't really want to dive onto the surface of Mars so we had to back off of the rear ramp which had deployed properly onto the ground and was at a reasonable angle to go down to. When we got down to the bottom of that ramp there was a wonderous rock sitting right next to us, within a half of a wheel turn or half of a rover turn away from us that was called Barnacle Bill for its nubby appearance. The first thing we did was to turn towards it and place the APXS up against Barnacle Bill. To our surprise we found higher silica rock than we really expected. Early on, one of the first things we found in the mission which was truly astounding for us.

Joy Crisp video
Joy Crisp audio --

If the numbers are correct, then it indicates that Barnacle Bill may have an andesitic composition and what that means is that it has more silica than the type of rocks that we see in Hawaii; the black lava flows that just ooze out and flow and spread out and they just flow easily over the surface.

Ron Greeley video
Ron Greeley audio --

Barnacle Bill is exciting to us because of its chemical composition. It shows a very high silica content which would suggest its been cooked and evolved through time. This is the first time a rock like this has been seen on Mars. So this is a very exciting discovery.