Explanation: NASA Ames's researcher, and New Horizons geology group lead, Jeff Moore (right) answers an audience question during PLUTO-PALOOZA during Astronomy Day at the California Academy of Sciences, April 25th, 2015. Also seen, CAS moderator Bing Quock (kneeling, left), Mark Showalter (SETI Institute) and SwRI's Tiffany Finley.


Image credit: Lee Hobson, Johns Hopkins University Applied Physics Laboratory.