Neptune's Discovery -- Article in Astronomy Magazine. Visit

Asteroid Discovery Circumstances -- For each minor planet: Where & when found, & by whom. Visit

Is Mars Habitable? -- A. R. Wallace's 1907 critique of Lowell's Book 'Mars & Its Canals' Visit

The Planet Mars: A History of Observation & Discovery -- On-line version of the book by William Sheehan. Visit

Exploring The Planets-Discovery -- The five known in antiquity, three more since the telescope, and Ceres. Visit

Orbits & Gravitation -- The development of the mathematics of planetary motion. Visit

Neptune & Pluto -- Mathematical discovery of planets Visit

Exploring the Moon -- Timeline of Lunar exploration. Visit

When Did the asteroids Become Minor Planets? -- Discusses the discovery of the first asteroids, their designation as planets, and their reclassification. Visit