Planets
By the current count of astronomers, our solar system includes 8 planets and 5 dwarf planets. The planets were formed during the process of solar system formation, when clumps began to form in the disk of gas and dusk rotating about our young Sun. Eventually, only the planets and other small bodies in the solar system remained. The four rocky planets at the center of the solar system Mercury, Venus, Earth, Mars, are known as the inner planets. Jupiter, Saturn, Uranus, and Neptune are all composed primarily of gas and are known as the outer planets. Find out more about the planets through the links below.
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Explore Planets
What is a Planet?
It may surprise you, but astronomers don't really have a good definition of a "planet". Because ...Read more
Mercury
Mercury, the planet nearest the Sun, is also the smallest planet in the Solar System. Only ...Read more
Venus
Fair but inhospitable Venus, a "Sister" planet to the Earth that is very different from our ...Read more
Mars
Mars, Earth's outer neighbor, is the fourth planet from the Sun. Mars' bright appearance and ...Read more
Jupiter
Jupiter is the largest planet in the solar system. When approached from afar, its fantastic ...Read more
Saturn
Saturn, the sixth planet from the Sun, has the most spectacular set of rings in the solar system. ...Read more
Uranus
Uranus, the seventh planet from the Sun, has its spin axis almost in the plane of its orbit ...Read more
Neptune
Neptune, the eighth and furthest planet from the Sun, is a very cold place. Its bluish color ...Read more
Dwarf Planets
In 2006 the International Astronomical Union (IAU) approved a new classification scheme for ...Read moreMore about Planets
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Did you know?
Did you know that Saturn has a strange hexagon shaped cloud structure at its north pole?Did you know that there is a strange hexagon in the atmosphere at the northern pole of Saturn?
Earth and Space Science Concept of the Day
Do you know what this word or phrase means?Pleistocene
xPleistocene : The time period between about 10,000 years before present and about 1,650,000 years before present.
Click on the word to find out!
Research Highlights
Oldest Earth Mantle Reservoir Discovered
Researchers have found a primitive Earth mantle reservoir on Baffin Island in the Canadian Arctic. Geologist Matthew Jackson and his colleagues from a multi-institution collaboration report the finding--the...Read more
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