Asteroid Discovery Circumstances: For each minor planet: Where and when found, and by whom.
Exploring the Moon: Timeline of Lunar exploration.
Exploring The Planets-Discovery: The five known in antiquity, three more since the telescope, and Ceres.
Is Mars Habitable?: A. R. Wallace's 1907 critique of Lowell's Book "Mars and Its Canals"
Neptune and Pluto: Mathematical discovery of planets
Neptune's Discovery: Article in Astronomy Magazine.
Orbits and Gravitation: The development of the mathematics of planetary motion.
The Planet Mars: A History of Observation and Discovery: On-line version of the book by William Sheehan.
The Struggles to Find the Ninth Planet: A paper by Clyde Tombaugh relating his discovery of Pluto.