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Pluto: About

Pluto

What is Pluto?

Pluto, large, distant member of the solar system that formerly was regarded as the outermost and smallest planet. It also was considered the most recently discovered planet, having been found in 1930. In August 2006 the International Astronomical Union (IAU), the organization charged by the scientific community with classifying astronomical objects, voted to remove Pluto from the list of planets and give it the new classification of dwarf planet. The change reflects astronomers’ realization that Pluto is a large member of the Kuiper belt, a collection of debris of ice and rock left over from the formation of the solar system and now revolving around the Sun beyond Neptune’s orbit. (For the IAU’s distinction between planet and dwarf planet and further discussion of the change in Pluto’s classification, see planet.)

Pluto is not visible in the night sky to the unaided eye. Its largest moon, Charon, is close enough in size to Pluto that it has become common to refer to the two bodies as a double system. Pluto is designated by the symbol ♇.

Pluto is named for the god of the underworld in Roman mythology (the Greek equivalent is Hades). It is so distant that the Sun’s light, which travels about 300,000 km (186,000 miles) per second, takes more than five hours to reach it. An observer standing on Pluto’s surface would see the Sun as an extremely bright star in the dark sky, providing Pluto on average 1/1,600 of the amount of sunlight that reaches Earth. Pluto’s surface temperature therefore is so cold that common gases such as nitrogen and carbon monoxide exist there as ices.

Because of Pluto’s remoteness and small size, even the best telescopes on Earth and in Earth orbit could resolve little detail of its surface. Indeed, for decades, such basic information as its radius and mass had been difficult to determine. It was not until Pluto was visited by the U.S. spacecraft New Horizons, which flew by Pluto and its satellite Charon in July 2015, that many key questions about it and its environs were answered. Continue reading from Britannica

Watch Videos about Pluto

Books and Videos about our Solar System

Our solar system formed about 4.5 billion years ago from a dense cloud of interstellar gas and dust. The cloud collapsed, possibly due to the shockwave of a nearby exploding star, called a supernova. When this dust cloud collapsed, it formed a solar nebula—a spinning, swirling disk of material.

At the center, gravity pulled more and more material in. Eventually the pressure in the core was so great that hydrogen atoms began to combine and form helium, releasing a tremendous amount of energy. With that, our Sun was born, and it eventually amassed more than 99 percent of the available matter. Continue reading from NASA

Link to Sizing Up the Universe by Richard Gott in the Catalog
Link to Death by Black Hole by Neil DeGrasse Tyson in the Catalog
Link to The Outer Solar System by Britannica Learning in Hoopla
Link to How To Read The Solar System by Paul Abel in Hoopla
Link to the secret lives of planets by paul murdin
link to stars and planets by ian ridpath in the catalog
Link to Solar system by Marcus Chown in the catalog