Shop Windows to the Universe

Our Glaciers: Then and Now activity kit helps you see the changes taking place in glaciers around the world. See all our activity kits and classroom activities.

Exploratour: NASA's Exploration for Life

Some forms of bacteria are known as Archaea
Click on image for full size
JPL/NASA

To date, the oldest known life forms are certain types of bacteria that have been found in Australian rocks that date back 3.5 billion years ago. At this time, oxygen was not present in the Earth's atmosphere, thus these bacteria must have been able to live without breathing oxygen.

These bacteria have been found within rock itself, miles underneath the surface.

Bacteria such as this give off ammonia as a waste product. Thus one way to detect increased activity by such creatures is to measure levels of nitrogen in the atmosphere.

This is page 5 of 20

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!

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

ExploraTour - Looking at the World in a Different Light

Look at the bed below the body of the sleeping man. You can still see where he was lying down. The heat from his body warmed up the bed sheets which are now radiating infrared light toward your eyes....more

ExploraTour - Looking at the World in a Different Light

All warm objects (not just people) release infrared light. Warmer objects give off more infrared light. Very hot objects radiate other types of light as well. Click on the picture to see the infrared...more

ExploraTour - Looking at the World in a Different Light

What kinds of light can people see? Our eyes can see visible light. When it passes into our eyes different types of visible light create different sensations that we see as colors. ...more

ExploraTour - Looking at the World in a Different Light

Imagine you found a pair of special glasses that not only gave you telescopic vision but gave you the ability to see all forms of radiant energy. The universe in visible light contains all the familiar...more

ExploraTour - Looking at the World in a Different Light

This is a volcano on the island of Miyake in Japan. It has erupted, sending hot lava and ash into the air, a total of ten times. The time after one eruption until the next occurred was about twenty years...more

ExploraTour - Looking at the World in a Different Light

This is a picture of a galaxy in visible light. A galaxy is a large number of stars, some like our sun, some bigger, some smaller and all moving together through space. This galaxy is called Centaurus...more

ExploraTour - Looking at the World in a Different Light

This is a plant in Gary, Indiana where power is made. We use power to run things like television sets, radios, lights, and microwave ovens. The picture looks very strange because it was taken in infrared....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