Couldn't find element LayerAd

Error finding content

Unmanned Space Exploration of Planets, Dwarf Planets, Asteroid Belt - Windows to the Universe

Shop Windows to the Universe

Arches National Park Geology Tour provides an extensive, visually rich description of the geology of Arches, by Deborah Ragland, Ph.D. See our DVD collection.

The Planets and Space Exploration

The four planets at the center of the solar system are solid, rocky bodies like the Earth. They include Mercury, Venus, and Mars. Jupiter, Saturn, Uranus, and Neptune are all made mostly of gas and are called giant planets because they are so large compared to Earth.

Their are several dwarf planets that are much smaller than Earth. Pluto, Haumea, Eris, Makemake, and the asteroid Ceres are all dwarf planets.

Unmanned spacecraft have traveled to all the planets in the solar system and taken pictures of the planets and many of their moons. They have also taken measurements that tell us what the planets are like inside.

Big, Bigger, Biggest

A Solar System Model Builders Guide

Shop Windows to the Universe Science Store!

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.

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Dwarf Planets

In 2006 the International Astronomical Union (IAU) approved a new classification scheme for planets and smaller objects in our Solar System. Their scheme includes three classes of objects: "small solar...more

Pluto

Pluto is a frigid ball of ice and rock that orbits far from the Sun on the frozen fringes of our Solar System. Considered a planet, though a rather odd one, from its discovery in 1930 until 2006, it was...more

Eris - a dwarf planet

Eris is a dwarf planet in our Solar System. Eris is a lot like Pluto, which is also a dwarf planet. Eris and Pluto are both very far from the Sun. They are both very, very cold. Eris was discovered in...more

Makemake: a Dwarf Planet

Makemake is a dwarf planet in our Solar System. Makemake was discovered in March 2005 by a team of astronomers led by Mike Brown. Makemake officially became a dwarf planet in July 2008. There were three...more

The Solar System

The solar system is made up of the Sun, the // Call the planets count function defined in the document head print_planet_count('planets'); planets and // Call the planets count function defined in the...more

The Beginning of the Solar System

Scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the expl osion of a nearby star (called a supernova). This explosion made waves in space...more

What is a planet?

Do you know what a planet is? Guess what... astronomers are not quite sure what a planet is! Mercury, Venus, Earth, and Mars are the planets closest to the Sun. They are definitely all planets. They are...more

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