TUCSON, Sept. 2 (UPI) -- Observations made by the Hubble Space Telescope have revealed the presence of sulfur, sulfur dioxide and graphitized carbon on Ceres. It's the first time the three chemical compounds have been found on an asteroid.
Hubble imaged Ceres using its ultraviolet-visible sensor and beamed the results back to Earth where researchers with the Planetary Science Institute compared the results to ultraviolet-visible frequencies emitted by sulfur, sulfur dioxide and graphitized carbon.
Additional wavelengths imaged by NASA's Dawn spacecraft helped scientists confirm the accuracy of Hubble's observations and the presence of the three special chemicals.
The presence of graphitized carbon is indicative of a carbon-rich environment that has long been bombarded by high energy particles. Such is life for objects in the asteroid belt, which bisects the space between the orbits of Mars and Jupiter.
"For the first time, a carbon-rich asteroid has been observed in the spectral region where graphitized carbons show unique spectral features," PSI senior scientist Amanda Hendrix said in a news release. "Other dark asteroids probably have graphitized carbon on their surfaces as well."
"This is a window to evidence of the effects caused by direct exposure to space for a primitive asteroid surface," added Faith Vilas, also a senior scientist at PSI.
Because both sulfur and sulfur dioxide are relatively volatile, they're likely to be soon sublimated and lost to space. The compounds could also make their way to shadowed and sheltered craters where they would remain stable.
Scientists believe these compounds are relatively fresh, which is compatible with previous observations that suggest some sort of geothermal activity on the dwarf planet.
"It may be that sulfurous materials are involved in the activity," added Hendrix. "It is remarkable that Ceres has this graphitized carbon covering much of its surface -- which tells us that it's been exposed to weathering processes for eons -- and yet Ceres also shows evidence of relatively young, fresh materials as well."
The new research was published this week in the journal Geophysical Research Letters.