Impact Excavation on Asteroid 4 Vesta: Hubble Space Telescope Results

• Published in: Science
• Main Authors: Thomas, Peter C., Binzel, Richard P., Gaffey, Michael J., Storrs, Alex D., Wells, Eddie N., Zellner, Benjamin H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Association for the Advancement of Science (AAAS) 1997
• Subjects: Multidisciplinary; South pole
• Online Access: http://dx.doi.org/10.1126/science.277.5331.1492; https://www.science.org/doi/pdf/10.1126/science.277.5331.1492

Hubble Space Telescope images of asteroid 4 Vesta obtained during the favorable 1996 apparition show an impact crater 460 kilometers in diameter near the south pole. Color measurements within the 13-kilometer-deep crater are consistent with excavation deep into a high-calcium pyroxene-rich crust or olivine upper mantle. About 1 percent of Vesta was excavated by the crater formation event, a volume sufficient to account for the family of small Vesta-like asteroids that extends to dynamical source regions for meteorites. This crater may be the site of origin for the howardite, eucrite, and diogenite classes of basaltic achondrite meteorites.