Asteroid Discovery Circumstances
For each minor planet: Where and when found, and by whom.

Neptune and Pluto
Mathematical discovery of planets

Orbits and Gravitation
The development of the mathematics of planetary motion.

Exploring the Moon
Timeline of Lunar exploration.

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

Notes on Sunspot Observations
John Winthrop's 1739 notes, from the collected papers of Fredrick Kilgour.

Neptune's Discovery
Article in Astronomy Magazine.

Is Mars Habitable?
A. R. Wallace's 1907 critique of Lowell's Book "Mars and Its Canals"

The Face of the Moon
A catalog for an exhibition of rare books and maps. Includes sample pictures from Galileo to the Apollo missions.

The Struggles to Find the Ninth Planet
A paper by Clyde Tombaugh relating his discovery of Pluto.