- Asteroids are rocky and metallic objects that orbit the Sun but are too small to be considered planets. They are known as minor planets -- Explore the worlds of asteroids.solarviews.com/eng/asteroid.htm
- Asteroids, from ORRERY: the Solar System in action.www.harmsy.freeuk.com/asteroids.html
- A huge asteroid may crash into Earth ... in 878 years. How many others sail through the sky unseenwww.csmonitor.com/2002/0405/p03s01-stss.html