Nearly half the largest rocks strewn across the asteroid 433 Eros come from material blasted from a single impact, a new analysis reveals. A detailed study of Eros-the first asteroid that a spacecraft has landed on (SN: 7/21/01, p. 38: Landing data confirm Eros' primitive nature)–reveals that among 6,760 rocks larger than 15 meters across, 44 percent originated from what is now a crater called Shoemaker. This 7.6-kilometer-wide depression lies at one end of the asteroid.
Peter C. Thomas of Cornell University and his colleagues found that the placement of the large rocks matched the predicted paths of debris ejected by the impact that created the Shoemaker crater. Although some of the debris "went straight up and straight down," other chunks traveled as far as two-thirds of the way around the rotating, 34-km-long asteroid, Thomas notes.