dwarf planet

[ dwawrf plan-it ]

noun

, Astronomy.

1. a spherical celestial body revolving about the sun, similar to a planet but not large enough to gravitationally clear its orbital region of most or all other celestial bodies. In 2006, the planet Pluto was reclassified as a dwarf planet.

dwarf planet

noun

1. any celestial body within the solar system that is larger than a satellite but smaller than a planet, and that orbits the sun

dwarf planet

1. A celestial body that orbits the Sun and is massive enough to assume a nearly spherical shape, but that does not clear other bodies from the neighborhood around its orbit and is not a satellite of a planet. Dwarf planets include Ceres, Pluto, and Eris. This category was created by the International Astronomical Union in 2006.

Word History and Origins

Origin of dwarf planet¹

First recorded in 1990–95

Example Sentences

By now, there are at least 150 of these dwarf planets, and most people have no clue, he says.

From Science News

Consider Ceres, the first of what are now known as dwarf planets to be discovered.

From Science News

The largest asteroid and smallest dwarf planet in the solar system could be home to liquid water, sitting deep underground.

From MIT Technology Review

There’s no shortage of new proposals for future missions to study the dwarf planet, including ones that would even attempt a sample return mission.

From MIT Technology Review

Ceres, a dwarf planet that sits between Mars and Jupiter, was studied by NASA’s Dawn probe from orbit from 2015 to 2018.

From MIT Technology Review