"X-rayted" Adventures in Space: Results of the NEAR X-ray Spectrometer from Eros

Larry R. Nittler
Carnegie Institution of Washington

The Near Earth Asteroid Rendezvous (NEAR) spacecraft orbited the s-class asteroid 433 Eros for one year ending in February, 2001. One of the instruments in NEAR's science payload, the x-ray spectrometer (XRS), returned a wealth of data about the surface composition of the geochemically key elements Mg, Al, Si, S, Ca and Fe. This talk will discuss XRS data obtained during major solar flares. These data, together with information from other NEAR instruments indicate that Eros is similar to but subtly different from the most common type of meteorites hitting the earth, ordinary chondrites. Eros is clearly a primitive, undifferentiated body, but it may have sampled different nebular processes than are recorded in known meteorite samples. There is evidence for surface losss of sulfur, probably due to impact- or photo-induced S volatization