Here is a refresher on the two bright spots that some people think is ice, and others even propose some sort of bioluminescence:

The two brightest spots on dwarf planet Ceres, which have fascinated scientists for months, are back in view in the newest images from NASA’s Dawn spacecraft. Dawn took these images on April 14 and 15 from a vantage point 14,000 miles (22,000 kilometers) above Ceres’ north pole.

The images show the brightest spot and its companion clearly standing out against their darker surroundings, but their composition and sources are still unknown. Scientists also see other interesting features, including heavy cratering. As Dawn gets closer to Ceres, surface features will continue to emerge at increasingly better resolution.

What do you think?  Are these just reflections from ice and the sun, or perhaps salt deposits?  Or are they something else?  Feel free to comment and check back as more data comes in!

thanks to NASA for the great info