Most Detailed Analysis of Up-Close Images Sat. Early Moon Probes Flat spots exist on floors of craters and other depressions. Large boulders are sunk partway into the asteroid's regolith, or soil. Hits House-sized boulders Small boulders, up to the size of a house, are plentiful on Eros.
Researchers estimate there are about a million such rocks total.
Clamoring up on one of these larger boulders, a visitor could in some regions get a view of all horizons, which would fall away quickly on the small rock. Researchers are nearly certain that dust or small pebbles coat parts or all of the asteroid, but images are not of high enough resolution to determine this with certainty. A decade ago, no one expected an asteroid of this size to have enough gravity to retain small particles. Smaller boulders, likely distributed over the eons during many collisions with other space rocks, are everywhere. These boulders have been spotted before, but the new study shows their prevalence.