Just as quickly, they slewed Hubble back, before the sun reemerged. After several repetitions of this choreography, Esposito and his team finally got their views of Venus. But Vesta's spectra also intrigue scientists. Ground-based observations indicate that Vesta represents the only known parent of a class of stony meteorites called basaltic achondrites. Researchers believe that some pieces chipped from Vesta by collisions with other asteroids ultimately fall to Earth as meteorites of this type.
Basaltic achondrites lack the rounded particles, or chondrules, found inside most stony meteorites.
Because they have undergone melting and cooling, these achondrites have a much more diverse composition from crust to core than chondrites. Planetary scientists suspect that Vesta has a similarly diverse makeup. Late last year, Hubble's wide-field and planetary camera took snapshots of Vesta though several colored filters. The images resolve Vesta's surface into a highly varied mix of dark and bright regions, says Zellner , an astronomer at Georgia Southern University in Statesboro. Analysis of the images over the next year should determine whether the surface variation comes entirely from lava flows or whether debris in the asteroid belt has cracked open Vesta's surface, allowing a peek beneath the crust.