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Pluto

The prototype “dwarf planet,” Pluto orbits the Sun at an average distance of 39.5 times the distance between Earth and Sun. Pluto has a mass 0.002 times the mass of Earth and a radius 0.18 times the radius of Earth. It is a small body made of water ice, and temperatures there do not rise above minus-223 degrees Centigrade. Pluto has five known moons. Discovered in 1930, it originally was classified as a planet, but was demoted in 2006.

Resources

Pluto February 19, 2016

Remnants from the Beginning June 10, 2010

Radio Programs

Pluto at Opposition A little world gets pushed around July 15, 2021

Deep Ocean A deep and ancient ocean on Pluto July 14, 2021

Building a World Assembling a small planet July 13, 2021

Beyond Neptune Denizens of the deep solar system May 26, 2021

Changing Skies? Pluto may be losing its atmosphere February 3, 2021

Getting Moons Many ways to acquire moons September 23, 2020

Moon and Pluto Lining up with Pluto November 12, 2018

Plutonian Names New names for a distant world November 3, 2017

Kuiper Belt Discovering the Kuiper Belt August 30, 2017

Looking for Life Looking for life in a cold ocean March 28, 2017

Red Ice A “beanie cap” for Pluto’s big moon December 27, 2016

Icy Pluto Pluto’s icy “heart” December 26, 2016

One Year Later, II Creation from cosmic violence July 19, 2016

One Year Later One year after Pluto July 18, 2016

Plutonium A new element for a new world — after this. February 24, 2016

Featured Images

Building Worlds July 13, 2021
New Horizons view of haze in Pluto's atmosphere

Changing Skies? February 3, 2021
Enhanced-color image of Charon from New Horizons

Charonian Chapeau December 27, 2016
View of ice field on Pluto from New Horizons

Plutonian Lava Lamp July 18, 2016
Backlit view of Pluto landscape from New Horizons

Hazy Skies September 22, 2015
New Horizons view of young mountains on Pluto

Ice Mountains July 15, 2015
July 12 views of Charon and Pluto from New Horizons

Hours Away July 13, 2015
July 8 view of Charon, Pluto from New Horizons

Dynamic Duo July 10, 2015
Artist's concept of New Horizons passing by Pluto

First Encounter July 9, 2015
New Horizons view of Pluto and Charon, July 1, 2015

Best Shot July 7, 2015
Diagram shows the location of the Kuiper Belt

Icy Realm July 6, 2015
Three dwarf planets shown to scale with Earth and Moon

Dwarf Planets January 5, 2015