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Pluto and Beyond

name with simble Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Pluto and beyond
Mercury Venus Our Earth Mars Jupiter Saturn Uranus Neptune Pluto and beyond

© Adolf Schaller and Donna Tracy, OmniCosm Studios
Painting by Adolf Schaller, OmniCosm Studios

The Distant Frontier

The outer solar system is an unexplored wilderness of frozen worlds. Pluto and its largest companion, Charon, orbit there.

Frontier Worlds

Frigid Pluto lies in the solar system’s outer reaches. It orbits far from the Sun along with its companion Charon. The surfaces of these two worlds are frozen ice deserts.

Exploring the Kuiper Belt

© NASA/NSSDC Image Catalog
Pluto and Charon were once thought to be the most distant outposts of the solar system. We now know they are among the nearest and largest members of a vast population of icy worlds called the Kuiper Belt. It extends out from Neptune’s orbit and contains materials that date back to the formation of the Sun and planets.

Unexplored Pluto

We can observe Pluto from Earth. At the end of the twentieth century, spacecraft had explored many worlds, but not tiny Pluto.

What We Know About Pluto

Pluto's frigid surface is frosted with methane ice and scarred by dark markings. Charon is covered with water ice. Distance blurs our view of these worlds, but future missions will reveal more details about them.

How Big Are They?

Viewed from Earth, Pluto and Charon are dim specks of light. If they were in orbit around our planet both worlds would be dwarfed by the Moon.

Discoveries at the Frontier

© Los Angeles Times
Los Angeles Times, March 14, 1930
© Los Angeles Times
Los Angeles Times,
March 16, 2004

Astronomer Clyde Tombaugh found Pluto on the frontier of the solar system in 1930. Today astronomers regularly discover other worlds in the Kuiper Belt wilderness beyond Neptune and Pluto. Icy objects like Sedna (below) challenge Pluto’s standing as a planet, as well as our own perception of what a planet is. These bodies may be the purest leftovers from the solar system’s birth cloud.

Discovering Sedna

© NASA/Caltech