Glossary term: Near Earth Objects

Also known as NEO, NEA, Near-Earth Asteroid, NEC, Near-Earth Comet, PHA or Potentially Hazardous Asteroid

Description: In addition to the Sun and planets, our Solar System contains numerous smaller bodies, notably asteroids and comets. An asteroid or comet colliding with Earth can have disastrous consequences. None of the objects we know is on a collision course with Earth, but there are a number it makes sense to keep an eye on, nonetheless. Any asteroid or comet that, on its orbit, comes closer to the Sun than 1.3 times the Earth–Sun distance is called a Near-Earth Object (NEO). Most NEOs are Near-Earth Asteroids (NEAs), although some are Near-Earth Comets (NECs; only comets with periods less than 200 years are counted). Larger objects that come closer to Earth's orbit than 5% of the Earth–Sun distance are called Potentially Hazardous Objects (PHOs); most are Potentially Hazardous Asteroids (PHAs).

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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".