Ceres Bright Spots Clear In Images But NASA Still Clueless About Origin

Dawn provided the perfect feed for science fiction lovers and conspiracy theorists when it spotted Ceres' famed 'bright spots' in March. Months on, NASA is still miles away from explaining them.

High resolution images taken earlier this month when Ceres entered a smaller mapping orbit around the dwarf planet showed the spots in greater detail than before but offered no clues to what could be causing them. It was confirmed earlier by researchers at NASA's Jet Propulsion Laboratory that the spots are reflections. Though origins of the reflecting material remain unknown, ice and salt have been speculated to cause the sparkle.

"Reflection from ice is the leading candidate in my mind, but the team continues to consider alternate possibilities, such as salt. With closer views from the new orbit and multiple view angles, we soon will be better able to determine the nature of this enigmatic phenomenon," said Chris Russell, principal investigator for the Dawn mission.

NASA had earlier asked people to guess what is causing the bright spots and offered options including volcanic activity.

The two big spots seen in the images exist in a crater about 55 miles across and are a cluster of smaller spots. Dawn's spectrometer also captured visible and infrared images of the planet's northern hemisphere. The instrument is said to be essential in determining the nature of the spots.

The images were taken from a distance of 2,700 miles on June 6.