Descent to a Comet From the NASA Astronomy Picture of the Day web site Gas and Snow Jets from Comet Hartley 2 700 Kilometers Below Comet Hartley 2 Comet Halley's Nucleus: An Orbiting Iceber Contrasting Terrains on Comet Churyumov-Gerasimenko 62 Kilometers above Comet Churyumov-Gerasimenko Descent to a Comet Welcome to a Comet Apogee Moon, Perigee Moon Surreal Moon Red Moon, Green Beam On a Blue Moon From the Moon to the Earth