With Pluto-fever at full fervor the past several weeks, UCLA’s own Dr. Chris Russell found himself before members of Congress to discuss findings from Dawn space exploration mission, which is exploring the asteroid belt between Mars and Jupiter.
“It’s the only spacecraft to orbit two extraterrestrial bodies beyond the Earth,” Russell noted the morning of July 28 during his testimony at a hearing of the House Committee on Science, Space and Technology.
Russell is a professor of Earth, planetary and space sciences at UCLA, receiving his Ph. D. from the university in 1968. He has published more than 1,500 scientific papers that have received more than 44,000 citations, and he is currently the principal investigator of the Dawn mission.
Dawn is the ninth mission in the NASA Discovery Program. The space probe was launched on Sept. 27, 2007, at a relatively low cost, for a focused investigation that was selected by peer review from proposals by planetary scientists. It is the first scientific mission to use solar-electric ion propulsion.
Dawn set a course for the main asteroid belt between Mars and Jupiter, which scientists believed could hold a host of important findings — masses from the asteroid belt have hit Earth as meteors.
Dawn first orbited protoplanet Vesta in 2011, which is the most massive asteroid in the main belt. Dawn was able to take pictures and eventually produce color images, ultimately measuring infrared, gamma rays, gravitational field for mass and elemental composition.
“We learned a lot about Vesta and we believe Vesta is a precursor to the bodies that formed the Earth,” Russell said.
In March of this year, Dawn finally reached dwarf planet Ceres.
“We are now looking at Ceres from about 4,000 kilometers, and moving down to get a higher resolution,” Russell said.
Two famous landmarks have been observed on Ceres. The Occator Crater included several bright spots those scientists believe may have been salt left over from evaporating water, as occurs in Earth’s deserts. They also examined a three-mile high mountain, which has dirt on its top and ice coming down its sides.
“We are totally surprised by the Pluto observations, which were very much like the mountain I show you here,” Russell told the Congress members. “Ceres is an object with potential biological interest. It has water and heat from the Sun and the interior. The astrobiological community is very interested in Ceres. It is relatively easy to reach with a reasonable payload. We believe that Dawn, with its small exploratory payload, has only scratched the surface, so to speak, of what can be done.”
Russell finished his testimony by thanking Congress for its continued financial support for space exploration, and stressed the need to continue forward. The Dawn mission will wind down in 2016.
“This support has brought a treasury of knowledge and a legacy for future generations,” he concluded.