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Exploratour - Life in the Solar System

This is an image of Comet Kohoutek.
Click on image for full size
NASA

Believe it or not, many scientists believe that life may have begun on these distant, solar system traveling objects. Out in their distant home, the Oort Cloud, comets are exposed to the kind of cosmic radiation which provides the energy needed to form long, complex molecules such as amino acids, proteins, and even polycyclic aromatic hydrocarbons (PAH's).

As we've said, because it is cold, it may take millions of years for these molecules to form. So the possiblity that life forms as sophisticated as bacteria could presently live in this environment is remote. Nevertheless, over the age of the solar system, and because comets periodically migrate to the inner solar system and swoop around the sun, spilling portions of their surfaces in their wakes, it is thought that comets may have brought some of life's beginnings to the inner solar system where they could thrive.

Read more about this possibility by reading our life section. Read more about different sort of unsophisticated life forms found on the primordial Earth by taking the Exporatour of Life on Earth.

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Our online store includes issues of NESTA's quarterly journal, The Earth Scientist, full of classroom activities on different topics in Earth and space science, ranging from seismology, rocks and minerals, oceanography, and Earth system science to astronomy!

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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 (not just people) radiate in the infrared. Warmer objects give off more infrared radiation. Very hot objects radiate other types of light in addition to infrared. Click on the picture...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

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