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Arches National Park Geology Tour provides an extensive, visually rich description of the geology of Arches, by Deborah Ragland, Ph.D. See our DVD collection.

Exploratour - Life on Mars?

Conclusion

In spite of Mars' similarity to Earth in size and proximity to the sun, the environment of Mars seems unfriendly toward life as we know it on Earth.

Mars is small, so there is not much gravity. For this reason, much of the atmosphere of Mars has drifted away. Unlike Earth, Mars has always lacked the protection from ultraviolet light provided by oxygen. With little atmosphere, and no ozone layer, there is less protection from the ultraviolet radiation of the sun, which is very harmful to life.

With little atmosphere, there is a only a small buffer between the surface and space itself. This means that the temperature above the surface is cold. With little atmosphere, there is only a little pressure, which sophisticated life forms such as humans need to keep blood from boiling. (Remember what happened to the characters of the movie "Total Recall" when they encountered the surface of Mars)!

The Viking lander, which carried the first experiments designed to detect life on Mars, did not find evidence of even the simplest organic molecule. The Mars Pathfinder came up with negative results when looking for signs of life on Mars. We know, however, that there are life forms on Earth which can survive in very harsh environments. It's possible that if life ever existed on Mars or if it will ever exist on Mars, it will look very different from that which we know!

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Cool It! Game

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ExploraTour - Looking at the World in a Different Light

Even though the sleeping man is no longer on the bed, 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 radiate in the infrared. The warmer the object, the higher the frequency and intensity of the radiation. Very hot objects give off other types of radiation in addition to infrared. Click...more

ExploraTour - Looking at the World in a Different Light

Your eye is a wonderful detector of visible light. Different frequencies of light produce different sensations in the eye which we interpret as colors. Our eyes detect light by using light sensitive components...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

The awesome power of a giant black hole was revealed by looking at this galaxy in three different types of light. The picture that you see is of Centaurus A, a very peculiar galaxy. A galaxy is just a...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