351E-376-Active Asteroids

When it was first spotted by astronomers at Space Watch on Kitt Peak, 2008 GO98 appeared to be one of many outer main belt asteroids moving through the night sky. 9 years later when my Catalina Sky Survey teammate Greg Leonard observed it with our 60 inch telescope on Mt. Lemmon it had a coma and a tail like a comet. Active asteroids like 2008 GO98 have asteroid orbits but sometimes show cometary activity which could be caused by a collision with another object and/or by thermal fracturing and ice sublimation caused by the slight warming they obtain from sunlight.