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 drawing represents a comet bringing atmospheric molecules and possibly the building blocks of life to the Earth's surface.
Click on image for full size
JPL/NASA

Did Comets bring Life to Earth?

Believe it or not, a few scientists believe it is possible that life may have begun on comets. Out in their distant home, the Oort Cloud, comets are exposed to the kind of energy needed to form the beginnings of life..

Comets might have brought some of the building blocks of life with them and left them on planets like Earth where they could live better. Comets have even hit a planet's surface, such as the case when comet Shoemaker-Levy 9 hit the planet Jupiter in 1995.

Shop Windows to the Universe Science Store!

"Science, Evolution, and Creationism", by the National Academies, provides fascinating background on these topics for all, and is particularly useful for the Earth and space science classroom. Check our other books in our online store.

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

CONTOUR on its Way to Catch a Comet!

NASA’s Comet Nucleus Tour (called CONTOUR) launched July 3, 2002. The CONTOUR spacecraft will fly by at least two comets. It will take pictures and collect dust from the nucleus of each comet. Learning...more

Earth's Primordial Atmosphere

Scientists ask many questions. One of the questions they like to ask is "Where did the atmosphere come from?" As always, scientists chip in with many different, and sometimes conflicting answers. Some...more

Can there be Life in the Environment of Jupiter?

Jupiter's atmospheric environment is one of powerful winds, going 250 miles per hour, and temperatures from -270 degrees to +32 degrees (freezing temperature). These winds make it hard for life forms to...more

The possible discovery of Life on Mars

In July, 1996 a team of scientists said that they had discovered possible fossils of bacteria in a meteorite named ALH84001 that came from Mars. It was found in Antarctica in 1984 after having landed there...more

The Environment of Saturn

Saturn's atmospheric environment is one of powerful winds, going 250 miles per hour, and temperatures from -270 degrees to +80 degrees. With winds like these, it is hard to have peace and quiet. The region...more

Can there be Life in the Environment of Titan?

The air of Titan is a lot like the Earth's, except that it is very cold, from -330 degrees to -290 degrees! Like the Earth, there is a lot of Nitrogen and other complex molecules. There also may be an...more

Autotrophs

Organisms that are able to "make their own food" are called autotrophs, meaning "self-feeders". Some examples of autotrophs are plants and algae (shown in the picture). Both plants and algae use photosynthesis...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA