Generally useful websites about the planets
Lunar and Planetary Science at the NSSDC. An indispensable, comprehensive collection of information about all known planets,, moons and planetoids, provided by NASA's National Space Science Data Center. I encourage you to bookmark this site in your Web browser. Especially useful here is the collection of planetary fact sheets.
Bill Arnett's Eight Planets is a good and comprehensive introduction to the planets.
Windows on the Universe. A glossy site aimed at primary education but containing lots of nice diagrams.
Joe Smyth's mineral database at the University of Colorado is a good reference for the structure and composition of minerals of terrestrial and extraterrestrial interest.
Shane Ross at Caltech has a great site full of orbital and satellite-trajectory simulations.
The Rings Node of NASA's Planetary Data System "is devoted to archiving, cataloging, and distributing scientific data sets relevant to planetary ring systems."
Additional, more specialized sites of particular value to AST 111 students:
NASA Johnson Space Center Moon Rock collection. All the data on all of them.
There's a useful Moon-rock and lunar-meteorite introduction provided by the Earth and Planetary Sciences department at Wash U.
Mariner 10 image archive at Northwestern U.
The US Geological Survey (USGS) home page is a portal to lots of data and analysis on geology and atmospheric science generally, though of course it emphasizes US territory.
Plate-tectonic animations at the UC Berkeley Museum of Paleontology.
Global surface-temperature data can be found at NASA's Goddard Institute for Space Studies.
NASA's Mars Exploration Program website is a portal to all of NASA's current missions to the Red Planet. A good thing, because they are getting so numerous as to be tedious to enumerate.
Malin Space Science Systems (MSSS) analyzes most of the images for the Viking, Mars Reconnaissance Orbiter and Mars Orbiter Camera missions.
Steve Ostro's asteroid-radar page contains lots of high-resolution images and movies of main-belt asteroids.
Cool simulations of Earth's lagrange-point (i.e. Trojan-like) asteroids can be found on Paul Wiegert's site at U. Western Ontario.
Jim Baer's asteroid-mass compilation is comprehensive and updated frequently.
Images from Galileo can be found, in abundance, here.
Still under construction!