Not just for landlubbers, the use of GIS technology has applications in astronomy. Browse this list for GIS and mapping resources related to outer space.
Deep Space Sky Mapping
Mapping software containing “the 250,000 star NASA Skymap database, the 18-million star Guide Star Catalog, the Saguaro Deep Sky database with about 10,000 objects, and about 10,000 asteroids and comets”.
Earth and Moon Viewer
Developed by John Walker of Fourmilabs, you can access various interactive views of the earth and sun.
Map-a-Planet
Hosted by the USGS Astrogeology Research Program, visitors can access imagery from a variety of planets and create customized maps.
Sky in Google Earth
From Google Earth: You can now explore the universe from the comfort of your chair. Zoom in to distant galaxies hundreds of millions of light years away, explore the constellations, see the planets in motion, witness a supernova explosion; it’s like having a giant, virtual telescope at your command — your own personal planetarium!
USGS Planetary Map Server
Data and maps from the USGS PIGWAD site (Planetary Interactive G.I.S.-on-the-Web Analyzable Database). View interactive geographic information about various planets with their online map server.
You forgot NASA World Wind. It has several data layers for Moon, Mars (both with terrain data), Venus, Jupiter and Sloan Digital Sky Survey.