Shop Windows to the Universe

Become a nitrogen atom in the nitrogen cycle in our Traveling Nitrogen Classroom Activity Kit/Game. See all our games, activity kits and classroom activities.
This image shows a Small Comet streak (in yellow box). This image was captured by the IRO on January 20, 1999. The longer black streaks are star trails.
Click on image for full size
Courtesy of Dr. Louis A. Frank, The University of Iowa and NASA

Small Comets Bring Water to Earth
News story originally written on March 1, 2001

There are small snow comets that crash into the Earth's atmosphere. About 20 snow comets weighing 20 to 40 tons each crash into the Earth's atmosphere every minute!

Scientists have seen these small comets in spacecraft images. They have also seen the comets using the Iowa Robotic Observatory (IRO) in Arizona.

The comets are no danger to life on Earth because they fall apart in the atmosphere. In fact, some scientists think that the water in the Earth's oceans might have arrived by way of these small snow comets. And that would have been helpful to life on Earth!


Last modified February 28, 2001 by Jennifer Bergman.

Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

Windows to the Universe Community

News

Opportunities

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

1999--A Year in Review...

It was another exciting and frustrating year for the space science program. It seemed that every step forward led to one backwards. Either way, NASA led the way to a great century of discovery. Unfortunately,...more

STS-95 Launch: "Let the wings of Discovery lift us on to the future."

The Space Shuttle Discovery lifted off from Kennedy Space Center on October 29th at 2:19 p.m. EST. The sky was clear and the weather was great. This was the America's 123rd manned space mission. A huge...more

Moon Found Orbiting Asteroid

Scientists found a satellite orbiting the asteroid, Eugenia. This is the second one ever! A special telescope allows scientists to look through Earth's atmosphere. The first satellite found was Dactyl....more

U.S. is Fed Up with Russia

The United States wants Russia to put the service module in orbit! The module is part of the International Space Station. It was supposed to be in space over 2 years ago. Russia just sent supplies to the...more

More on Recent Coronal Mass Ejection

A coronal mass ejection (CME) happened on the Sun last month. The material that was thrown out from this explosion passed the ACE spacecraft. ACE measured some exciting things as the CME material passed...more

Mother Nature's Air Conditioning

Trees and plants are a very important part of this Earth. Trees and plants are nature's air conditioning because they help keep our Earth cool. On a summer day, walking bare-foot on the sidewalk burns,...more

Planetary Alignment 2002

There is something special happening in the night sky. Through mid-May, you will be able to see five planets at the same time! This doesn't happen very often, so you won't want to miss this. Use the links...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part by the National Science Foundation and NASA, our Founding Partners (the American Geophysical Union and American Geosciences Institute) as well as through Institutional, Contributing, and Affiliate Partners, individual memberships and generous donors. Thank you for your support! NASA AGU AGI NSF