The Eros asteroid could have witnessed the formation of the Earth, according to a preliminary analysis of its surface composition using NASA's Near Earth Asteroid Rendezvous (NEAR) spacecraft. Analysis of solar X-rays from Eros' surface indicate that it has a composition similar to the chondrite meteorites found on Earth, which are believed to be primordial agglomerations of dust grains from the nebula that became the Sun and planets.
This image is a false color map of the area on Eros analyzed to date by the X-ray spectrometer on board NEAR. Red represents the brightest X-ray emissions, and light blue represents the least. Dark blue areas have not been mapped so far. Image A (top left) represents the area lit by a bright solar flare on 4 May 2000. Image B (bottom left) represents the area revealed by a solar flare on 19 July 2000. Images C (top right) and D (bottom right) are areas mapped under normal solar X-ray illumination. They are a composite of observations taken during the period 2 May to 7 July 2000. Image C is the accumulated, normal illumination map that corresponds to the same area lit up by the 4 May flare (Image A). Image D is the same for the area illuminated by the 19 July flare (Image B). Image C is concentrated in the crater Psyche, and Image D highlights the "saddle" region Himeros. Image Credit: NASA/Jack Trombka