Glossary term: Asteroid
Description: An asteroid is a small body that orbits around the Sun. Historically, the name asteroid was given to any astronomical body that orbits the Sun that was too small to resolve with a telescope and did not display the features of a comet, like a coma or tail. Now the term asteroid is only used for small bodies in the inner Solar System. Asteroids are solid bodies consisting of metals, rock, and ice. Most are piles of rubble bound together by gravity. Most asteroids have bumpy, uneven shapes although a small number of larger asteroids are spherical. Some asteroids have moons – other small asteroids which orbit them.Related Terms:
- Asteroid Belt
- Asteroid Family
- Cometary Coma
- Cometary Tail
- Near Earth Objects
- Solar System
- Small Solar System Body
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Term and definition status: This term and its definition is still awaiting approval
The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".
Ida and DactylCaption: This picture of the asteroid Ida with its satellite Dactyl was taken by the Galileo space probe in August 1993 from a range of 10,870 kilometers (6,755 miles). Ida is a heavily cratered, irregularly shaped asteroid in the main asteroid belt between Mars and Jupiter. This image is proof that asteroids like the 56 km large Ida can possess their own moons.
Credit: NASA/JPL credit link
License: PD Public Domain icons