Sol 4035, June 1, 2015. Private William Bratton was a member of the Lewis & Clark expedition — and also the namesake of a rock target for Opportunity at the northern edge of Spirit of St. Louis Crater.
The rock’s nature is uncertain, but one possibility being investigated is whether it is an impact breccia. It stands slightly higher than the surrounding parts of the outcrop.
The image at right is a composite of two Microscopic Imager frames; click to load a larger version.