Comets

Comets are remnants from the early days of the solar system, billions of years ago. Primarily made of ice and dust, these "dirty snowballs" orbit the sun and in habit the Oort cloud, an area in the outskirts of the solar system beyond Pluto. As comets approach the inner solar system, solar wind from the sun can sweep dust back into a long tail. When these comets are close enough to Earth, they can appear as dazzling objects in the night sky. Space probes from Earth have visited several comets to learn more about their composition. Learn more about comets, icy wanderers in the solar system.

Related Topics: Asteroids, Meteors, Shooting Stars and Fireballs, Rosetta Spacecraft, Stargazer Photos 

Latest Updates

This series of images of Comet 67P/Churyumov-Gerasimenko was captured by the Rosetta spacecraft's OSIRIS narrow-angle camera on Aug. 12, 2015, a few hours before the comet reached perihelion, or the closest point to the sun along its 6.5-year orbit.

Rosetta's 'rubber ducky' comet has ultraviolet auroras

By Hanneke Weitering published

Planets aren't the only things in the solar system with auroras. Comets can have them too, data from the European Space Agency's Rosetta mission has revealed.

An artist's depiction of the first identified interstellar object, 'Oumuamua.

Interstellar visitor 'Oumuamua could actually be a cosmic dust bunny

By Chelsea Gohd published

A new theory has emerged that the cigar-shaped space rock 'Oumuamua might actually be a dust bunny.

The Hubble Space Telescope captured this image of Comet NEOWISE on Aug. 8, 2020, after the object's close approach to the sun.

Hubble telescope catches stunning view of Comet NEOWISE after its spectacular summer sky show

By Elizabeth Howell published

The Hubble Space Telescope turned its powerful eyes to a celestial visitor to our skies — Comet NEOWISE, which put on a stunning show in the United States earlier this summer.

Astrophysicist Gianluca Masi of the Virtual Telescope Project captured this view of Comet C/2020 F3 (NEOWISE) on July 18, 2020.

Comet NEOWISE is making its closest approach to Earth. Here's how to see it live online.

By Hanneke Weitering last updated

Comet NEOWISE, as photographed by Joy Ng, a multimedia producer at NASA's Goddard Space Flight Center.

Comet NEOWISE: 10 big questions (and answers) about the icy wanderer

By Chelsea Gohd last updated

Comet NEOWISE has returned to the skies and is delighting skywatchers. So what makes this comet so special?

After dusk during July, comet C/2020 F3 (NEOWISE) will be visible low in the northwestern sky as it travels northwest in the sky below the constellation of Ursa Major. Mobile apps can help you find it. This chart shows the comet's path through the sky until mid-August, at 11 p.m. local time. Each night the comet will diminish in brightness — so look for it as soon as possible.

How to spot the bright Comet NEOWISE using mobile apps

By Chris Vaughan last updated

Skywatchers the world over are buzzing about Comet NEOWISE, the first easily-visible comet to appear in years. Your favorite mobile astronomy app can tell you when, where and how to look for it.

Comet NEOWISE shines above a SpaceX Falcon 9 rocket on the pad at Cape Canaveral Air Force Station in Florida. SpaceX posted this photo on Twitter on July 20, 2020.

Comet NEOWISE shines over SpaceX Falcon 9 rocket (photo)

By Mike Wall published

The gorgeous image shows Comet NEOWISE blazing above a Falcon 9 rocket that's poised to launch South Korea's first military satellite today (July 20).

Comet NEOWISE is seen by NASA’s Parker Solar Probe, which captured the comet's twin tail on July 5, 2020. The lower, broader tail is the comet’s dust tail, while the thinner, upper tail is the comet’s ion tail.

Replay: See Comet NEOWISE online tonight in a Slooh webcast

By Tariq Malik last updated

You can see Comet NEOWISE online tonight (July 18) in a lvie webcast from Slooh.

These false-color images of Comet NEOWISE show the concentration of sodium atoms in the comet's dusty ion tail. Astronomers created the images using the Planetary Science Institute's Input/Output facility near Tucson, Arizona. The image on the left shows light reflected off of cometary dust, while the image on the right shows light emitted by sodium atoms.

Comet NEOWISE has a sodium tail. Here's what it looks like.

By Elizabeth Howell last updated

Images of bright comet C/2020 F3 (NEOWISE) show signs of a sodium tail, giving scientists fresh insight on what's happening on the surface.

How to see Comet NEOWISE in the evening sky now. It won't be back for 6,800 years.

By Tariq Malik last updated

Comet NEOWISE is now visible in the evening sky for stargazers. It won't be back for 6,800 years.

Astrophotographer Bill Dunford, a NASA social media specialist at the Jet Propulsion Laboratory in Pasadena, California, captured this view of Comet NEOWISE when it was visible in the predawn sky in early July 2020.

How to photograph Comet NEOWISE: NASA tips for stargazers

By Chelsea Gohd published

Are you excited to spot Comet NEOWISE as it pops into view in the night sky? Do you want to try your hand at photographing the cosmic snowball?

Processed data from the WISPR instrument on NASA’s Parker Solar Probe shows great detail in the twin tails of Comet NEOWISE, as seen on July 5, 2020. The lower, broader tail is the comet’s dust tail, while the thinner, upper tail is the comet’s ion tail.

Dazzling Comet NEOWISE could be an astronomical bonanza

By Mike Wall published

Astronomers are buzzing about Comet NEOWISE, which observers under clear, dark skies in the Northern Hemisphere can currently see with the naked eye.

This image of comet NEOWISE was captured by NASA’s Solar and Terrestrial Relations Observatory, or STEREO, on June 24, 2020, as the comet approached the sun.

Comet NEOWISE spotted by more NASA spacecraft (video, photos)

By Mike Wall published

NASA's Parker Solar Probe isn't the only spacecraft doing some comet watching these days.

An unprocessed image from the WISPR instrument on NASA’s Parker Solar Probe shows Comet NEOWISE on July 5, 2020, shortly after its closest approach to the sun. The sun is out of frame to the left. The small black structure near the lower left of the image is caused by a grain of dust resting on the imager’s lens.

Amazing photos of Comet NEOWISE from the Earth and space

By Space.com Staff published

See photos of Comet C/2020 F3 NEOWISE, which is bright enough to spot with the naked eye, seen from Earth and space.

An unprocessed image from the WISPR instrument on NASA’s Parker Solar Probe shows Comet NEOWISE on July 5, 2020, shortly after its closest approach to the sun. The sun is out of frame to the left. The small black structure near the lower left of the image is caused by a grain of dust resting on the imager’s lens.

Dazzling Comet NEOWISE spotted by NASA sun-studying probe (photo)

By Mike Wall published

NASA's record-breaking Parker Solar Probe has given us a great new look at the gorgeous comet that's been gracing our predawn skies.

Astrophotographer Chris Schur captured this view of Comet NEOWISE F3 from Payson, Arizona before dawn on July 5, 2020.

Comet NEOWISE could give skywatchers a dazzling show this month. Here's what to know.

By Joe Rao last updated

Comet NEOWISE could become a tantalizing object for skywatchers in the July 2020 night sky.

Comet NEOWISE as seen from the International Space Station in a photograph shared by Russian cosmonaut Ivan Vagner on July 4, 2020.

Comet NEOWISE is 'an awesome sight' from space, astronaut says (video)

By Mike Wall published

Comet NEOWISE is starting to put on a show for skywatchers, and not just those of us restricted to Earth's surface.

Comet NEOWISE as seen from the International Space Station in a photograph shared by Russian cosmonaut Ivan Vagner on July 4, 2020.

Comet NEOWISE shines in stunning photos from the International Space Station

By Meghan Bartels published

Astronauts caught a stunning natural light show this weekend from a comet that has been dazzling skywatchers on Earth as well.

An animation of data taken by the SOHO spacecraft shows two newly discovered sungrazing comets, including the 4,000th such object discovered by the solar spacecraft.

4,000 comets! Sun-watching spacecraft's discoveries keep piling up

By Meghan Bartels published

A spacecraft that launched a quarter century ago to study the sun has discovered its 4,000th new comet in a spree of serendipitous science.

STEREO-A's view of the inner solar system between May 25 and June 1, 2020. Comet ATLAS streaks down across the screen as the planet Mercury enters at the left of the frame; meanwhile, the solar wind blows out from the sun on the left.

NASA sun observatory spies Comet Atlas in the solar wind. (Mercury, too!)

By Meghan Bartels published

You'll need a minute to take it all in, there's a lot going on in this stunning view of the inner solar system, including a comet, Mercury and some solar weather.