California Institute of Technology
The Discovery of Eris, the Largest Known Dwarf Planet
Until the discovery of Eris, Pluto was known as the largest Keiper belt object. This dwarf planet has replaced Pluto in size and is accompanied by a satellite that has been given the name Dysnomia. Learn about this distant world here...
University of California
Ucla: What Makes a Planet
This detailed essay defines planets and compares the characteristics to those of Pluto. Orbital graphs and background information clarify the change in Pluto's categorization. A copy of IAU's Resolution 5 is also contained in this essay.
Nine Planets
The Nine Planets: Pluto
This site contains copious information about Pluto. The site contains descriptive and statistical information, as well as a detailed article about the search for trans-Plutonian planets and the "Nemesis" hypothesis.
Famous Scientists
Famous Scientists: Clyde Tombaugh
Find out about Clyde Tombaugh, the scientist who discovered the dwarf planet Pluto in 1930, and also discovered a number of asteroids.
Science4Fun
Science4 Fun: Pluto
Learn fun facts and details about the atmosphere, geography, composition, and discovery of Pluto, a dwarf planet.
NPR: National Public Radio
Npr: Why Is the Sky Blue? (On Pluto, That Is)
Read about the atmosphere of Pluto.