National Aeronautics and Space Administration Logo
Follow this link to skip to the main content NASA Banner
Solar System Exploration
Comets: Kids
   Education   Events   Missions   News   FAQ 
   Overview   Read More   Science Targets   Gallery 
Comets - Icy Wanderers

See more kids' drawings...

Comets are big chunks of ice, rock and gas. They are dirty snowballs of leftovers from the beginning of our solar system. Comets get their name from the Greek word "kometes" (long hair) - a reference to their tails.

Comets are mysterious. Scientists think they might be able to tell us about the origins of our solar system.

Comets orbit the Sun like planets. Most comets orbit way out beyond the orbit of Pluto. It can take a comet hundreds or even millions of years to go once around the Sun. On Earth, it only takes 365 days. Most come from a super distant ring of debris around our solar system called the Oort Cloud.

A few comets close enough for us to see from Earth. They probably come from an area around Pluto called the Kuiper Belt. When Earth passes through the tail of a comet, we see a meteor shower.

Unless you could travel way out beyond Pluto, it would be hard to stand or land on a comet. When comets get close to the Sun, they begin spewing gas and dust. The debris form the head - or coma - and a tail. The tail always points away from the Sun. The only solid part is the nucleus in the middle.

If you did manage to land on a comet, you might end up getting blasted into space on a jet of gas and rock. Or, if your comet got too close to the Sun, it would break up completely. Gravity is so light you would feel like a feather.

Spacecraft that visit comets have to be tough. The rocks and debris in the tail can cause a lot of damage. In the next few years, scientists will use super tough spacecraft to catch pieces of a comet's tail and blast a football-field size hole in another comet to see what's inside the nucleus.

Want to learn more? Explore asteroids in depth at NASA's Solar System Exploration website.

Challenge Graphic
COMET CHALLENGE As a comet approaches the sun, does its head or tail lead the way? What about when it starts traveling away from the Sun? Hint: The answer is on this page.

Missions to Comets
Featured Mission: Stardust
Stardust will use a super light substance called Aerogel to capture pieces of the tail of a comet and return them to Earth.
More Missions to Comets
Past Missions
Present Missions
Go Figure!
Year Comet Wild 2 almost collided with Jupiter, bringing the comet into the inner solar system.
13,000 mph
Speed Stardust spacecraft will passed by Comet Wild 2 - six times faster than a bullet. About 21,000 kph.
Years it takes comets on the edge of our solar system to travel around the sun.
Years until Comet Hale-Bopp will again be visible from Earth. It was last visible in 1997.
Years it takes Comet Halley to orbit the sun. It was last visible in 1986.
Awards and Recognition   Solar System Exploration Roadmap   Contact Us   Site Map   Print This Page
NASA Official: Kristen Erickson
Advisory: Dr. James Green, Director of Planetary Science
Outreach Manager: Alice Wessen
Curator/Editor: Phil Davis
Science Writers: Courtney O'Connor and Bill Dunford
Producer: Greg Baerg
Webmaster: David Martin
> NASA Science Mission Directorate
> Budgets, Strategic Plans and Accountability Reports
> Equal Employment Opportunity Data
   Posted Pursuant to the No Fear Act
> Information-Dissemination Policies and Inventories
> Freedom of Information Act
> Privacy Policy & Important Notices
> Inspector General Hotline
> Office of the Inspector General
> NASA Communications Policy
> NASA Advisory Council
> Open Government at NASA
Last Updated: 20 Oct 2014