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Planetary Science

Solar System

Definition

The gravitationally bound system of the Sun and everything orbiting it: eight planets, dwarf planets, moons, asteroids, comets, and small bodies. Formed 4.6 billion years ago from a molecular cloud collapse. Extends to the Oort Cloud at roughly 100,000 AU.

Related Terms

Orbit

The curved path of a celestial object around a star, planet, or moon under gravity's influence. Orbits can be circular, ...

Asteroid Belt

A region of the solar system between the orbits of Mars and Jupiter where most asteroids are found. Despite popular depi...

Kuiper Belt

A circumstellar disc in the outer solar system from Neptune's orbit (30 AU) to about 50 AU. Home to Pluto and many icy b...

Explore Related Topics

Dive deeper into solar system and related concepts on Cosmos Observatory.

Solar System Explorer

Explore planets, moons, and orbital data.

Mars Rover Photos

Surface imagery from Curiosity and Perseverance.

Asteroid Tracker

Monitor near-Earth objects in real time.

Full Glossary

Browse all 66+ space and astronomy terms.

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