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.
TED Talks
Ted: Ted Ed: Nasa & Trappist 1: A Treasure Trove of Planets Found
Seven Earth-sized planets have been observed by NASA's Spitzer Space Telescope around a tiny, nearby, ultra-cool dwarf star called TRAPPIST-1. Three of these planets are firmly in the habitable zone. In this video, NASA Scientists...
NASA
Nasa: Solar System Exploration
Enter our solar system to interact with the planets, moons, asteroids, meteors, and more. Investigate with NASA scientists and explore missions related to space exploration. Read facts, compare statistics, look through resources, and...