Kuiper belt

The Kuiper belt ("KYE per") is an area of the solar system extending from within the orbit of Neptune (at 30 AU) to 50 AU from the Sun, at inclinations consistent with the ecliptic.

Related Topics:
Solar system - Orbit - Neptune - AU - 50 AU - Sun - Ecliptic

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Objects within the Kuiper Belt are referred to by the IAU as trans-Neptunian objects (a type of minor planet). They are sometimes also called asteroids.

Related Topics:
IAU - Trans-Neptunian object - Minor planet - Asteroid

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The outer boundary of the Kuiper belt is not defined arbitrarily; rather, there appears to be a real and fairly sharp dropoff in objects beyond a certain distance. This is sometimes called the "Kuiper gap" or "Kuiper cliff". The cause for this remains a mystery; one possible explanation would be a hypothetical Earth-sized or Mars-sized object sweeping away debris.

Related Topics:
Earth - Mars

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