Lissauer, Jack J. Space Science and Astrobiology Division, Planetary Systems Branch, Ames Research Center, National Aeronautics and Space Administration, Moffett Field, California.
Marley, Mark S. Space Science and Astrobiology Division, Planetary Systems Branch, Ames Research Center, National Aeronautics and Space Administration, Moffett Field, California.
Last reviewed:February 2019
Show previous versions
- Magnetic field
- Origin and evolution
- Related Primary Literature
- Additional Reading
The eighth planet in order of distance from the Sun and the outermost of the four giant planets in our solar system. Most of what is known about Neptune is the result of the flyby of the planet by Voyager 2 in August 1989, after the space probe had visited Uranus in 1986. The spacecraft discovered that Neptune has a ring system and gathered detailed images of the planet and its moons, including Triton, the seventh largest moon in the solar system. Overall, the Voyager results confirmed that Neptune (Fig. 1) is a near twin of Uranus in size, mass, and composition. With atmospheres and interiors that are strongly enriched in heavy elements, yet less massive than the gas giants Jupiter and Saturn, Neptune and Uranus make up a separate type of planet commonly termed "ice giants." Many planets of similar masses have been found in exoplanetary systems. Neptune and Uranus enable important case studies that help in understanding this common class of world. See Table 1 for planetary and orbital characteristics of Neptune. See also: Exoplanet; Jupiter; Planet; Saturn; Solar system; Space probe; Uranus
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 10,000 highly qualified scientists and 46 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