Planets
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http://www.bbc.co.uk/science/space/solarsystem/uranus/index.shtml
http://nssdc.gsfc.nasa.gov/planetary/factsheet/index.html
http://www.lpi.usra.edu/library/LISTS/planet_info.shtml
http://library.thinkquest.org/25763/msspart1.htm
Planetary fact sheets
Your Travel Guide to the Solar System
All your favourite planets are introduced here.
Solar System trading Cards
Choose a card and answer a quick question to get all the details of a planet or other heavenly body.
Online Explorations
Play Planet Impact, or whip up a batch of comets.