Comets

Animated GIF of comet approaching and receding.

Overview

Comets are frozen leftovers from the formation of the solar system composed of dust, rock, and ices. They range from a few miles to tens of miles wide, but as they orbit closer to the Sun, they heat up and spew gases and dust into a glowing head that can be larger than a planet. This material forms a tail that stretches millions of miles.

Comets are cosmic snowballs of frozen gases, rock, and dust that orbit the Sun. When frozen, they are the size of a small town. When a comet's orbit brings it close to the Sun, it heats up and spews dust and gases into a giant glowing head larger than most planets. The dust and gases form a tail that stretches away from the Sun for millions of miles. There are likely billions of comets orbiting our Sun in the Kuiper Belt and even more distant Oort Cloud.

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NASA/JPL-Caltech/VTAD

Featured Comets

Closeup view of a peanut-shaped comet with sunlight reflecting off it

Comet 103P/Hartley (Hartley 2)

Dark sky with streaks of light from the Perseid meteor shower.

109P/Swift-Tuttle

An image of comet Borrelly with sunlight reflecting off it.

Comet 19P/Borrelly

Image of Comet Halley

1P/Halley

Jet erupting from comet.

67P/Churyumov-Gerasimenko

bluish comet trailing dust and gas as it travels through space.

Comet 2I/Borisov

Image of comet 2P/Encke

2P/Encke

Two close up images of Comet Wild 2

81P/Wild (Wild 2)

Image of potato-shaped comet soon after NASA's Deep Impactor spacecraft hit the comet. Bright light is glowing from one end of the comet.

9P/Tempel 1

Image of comet Hale-Bopp

C/1995 O1 (Hale-Bopp)

Bright comet is seen above red Mars against a backdrop of stars

C/2013 A1 Siding Spring

Comet with bluish tinted tail

C/2012 S1 (ISON)

Artist's concept of cigar-shaped space rock.

'Oumuamua

Comet Shoemaker-Levy 9

Shoemaker-Levy 9

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