50 Our Solar System

Astronomers believe the solar system is about 4.6 billion years old . We base that idea through the study of meteorites and “dating” of these objects and observations of our Sun, as well as similar stars.

The Solar System is made up of one central star, eight (or nine, or ten…) known planets, satellites orbiting the planets, and miscellaneous debris; minor bodies; asteroids, meteoroids, comets, and dust, and what is known as the Kuiper Belt Objects and the Oort cloud .

Sun

One Central Star—Sun

Image of the Sun with some sunspots visible. The two small spots in the middle have about the same diameter as our planet Earth.
Public Domain | Image courtesy of NASA / ESA.

Planets

Rocky Planet Earth– Eight (or nine, or ten…) known Planets

Image of a Rocky Planet Earth.
Public Domain | Image courtesy of NASA / ESA.

Satellites

Satellite Io (Jupiter): Orbits Planets
Image of Jupiter’s Satellite, Io.
Public Domain | Image courtesy of NASA / ESA.

Minor Bodies

Asteroid-951 Gaspra
Image of Asteroid-951 Gaspra shows multitudes of small craters and large flat areas.
Public Domain | Image courtesy of NASA / ESA.
Comet Hale-Bopp
Image of a very bright Hale-Bopp Comet in the night sky.
CC BY-SA 3.0 | Image courtesy of Wikimedia Authors: E. Kolmhofer, H. Raab; Johannes-Kepler-Observatory, Linz, Austria.

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Introduction to Astronomy Copyright © by Lumen Learning is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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