Was Pallas, the second-largest asteroid, actually in that gray area between an asteroid and a small planet?
The answer, she found, was yes. Pallas, like its sister asteroids Ceres and Vesta, was that rare thing: an intact protoplanet. “It was incredibly exciting to have this new perspective on an object that is really interesting and hadn’t been observed by Hubble at high resolution,” Schmidt said of the first high-resolution images of Pallas, which is believed to have been intact since its formation, most likely within a few million years of the birth of our solar system. “We were trying to understand not only the object, but how the solar system formed,” Schmidt said. “We think of these large asteroids not only as the building blocks of planets but as a chance to look at planet formation frozen in time.” The research appears Oct. 9 in the journal Science. “To have the chance to use Hubble at all, and to see those images come back and understand automatically this could change what we think about this object – that was incredibly exciting to me,” Schmidt said. Pallas, which is named for the
