Stern, S. Alan Space Science and Engineering Division, Southwest Research Institute, Boulder, Colorado.
Last reviewed:August 2018
Show previous versions
- Pluto, published May 2017:Download PDF Get Adobe Acrobat Reader
- Pluto, published June 2014:Download PDF Get Adobe Acrobat Reader
- Early information
- New Horizons
- Size and density
- Surface and atmosphere
- Planetary status
- Links to Primary Literature
- Additional Readings
The largest dwarf planet in the solar system and a member of the Kuiper Belt of icy objects mostly beyond the orbit of Neptune. Pluto (Fig. 1) was discovered on February 18, 1930, by U.S. astronomer Clyde W. Tombaugh at the Lowell Observatory in Flagstaff, Arizona. Tombaugh discovered Pluto on photographic plates taken with a special astronomical camera as part of a systematic search. Pluto's name was suggested later in 1930 by Venetia Burney, an English schoolgirl. At the time and until 2006, Pluto was considered the ninth planet of the solar system in orbit around the Sun. However, in 2006, the International Astronomical Union reclassified Pluto as a dwarf planet, along with fellow Kuiper belt member Eric, discovered in 2003, and Ceres in the asteroid belt, among numerous other bodies. The population of dwarf planets far outnumbers the population of large planets, suggesting that solar system formation predominantly creates small planets, not large planets, as has been thought. See also: Kuiper Belt; Planet; Solar system; Sun
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information