red Centaurs

Red Centaurs are a rare class of Centaurs that appear to be covered in organic substances, giving the surface a strong reddish hue. Among them are Pholus and 1995 G0, observations of which by David Weintraub and his colleagues of Vanderbilt University, Nashville, using the 3-meter infrared telescope on Mauna Kea, Hawaii, and an optical telescope at Steward Observatory, revealed that they are redder than any other asteroids in the solar system. One possibility is that the organic coating is the result of prolonged bombardment by cosmic rays which has led to the formation complex polymers rich in carbon and nitrogen.