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Warnings: The True Story of How Science Tamed the Weather by Mike Smith tells the story of our storm warning system. See our online store book collection.

The Planets and Space Exploration

The four inner planets at the center of the solar system Mercury, Venus, Earth, Mars, are known as the terrestrial planets because they are solid, rocky bodies. Jupiter, Saturn, Uranus, and Neptune are all composed primarily of gas and are known as the Jovian planets or Gas Giants (Uranus and Neptune are sometimes called Ice Giants).

The space beyond Neptune contains thousands of icy worldlets that are not quite large enough to be full-fledged planets. Three dwarf planets - Pluto, Haumea, and Makemake - orbit in a region called the Kuiper Belt. Another dwarf, Eris, is also found beyond Neptune but in a more elliptical orbit.

The asteroid belt, between Mars and Jupiter, is made of thousands of chunks of rock which orbit the Sun. The dwarf planet Ceres orbits within the asteroid belt. Comets are small icy bodies that travel past the Sun and give off gas and dust each time they pass by.

Unmanned spacecraft have traveled to all the full-sized planets in the solar system and taken pictures of the planets and many of their moons. They have also taken measurements that tell us about the particle, electromagnetic, and gravitational environment near the planets. This information can be used to tell us about the planets interior, surface, atmosphere, and magnetosphere.

Big, Bigger, Biggest

A Solar System Model Builders Guide

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The Winter 2010 issue of The Earth Scientist, which includes articles on meteor cratering, classroom glaciers, podcasts in the classroom, and pyro-cumulonimbus clouds, is available in our online store.

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The Solar System

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF