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Ready, Set, SCIENCE!, by the National Research Council, focuses on K-8 science classsrooms. Check out the other publications in our online store, as well as classroom materials.

ExploraTour - How to Build a Star


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The sun's atmosphere acts as a thick filter through which the high energy gamma rays, generated in the solar core, must pass. These gamma rays are dangerous to humans. As they move through the sun's atmosphere they are converted into photons of harmless visible light. How very fortunate for us!

Here's how it works....

The gamma rays emitted during the proton-proton chain, collide with the electrons in the dense solar core, producing slightly lower energy photons at each encounter. Initially the gamma rays cannot move more than a fraction of a centimeter before colliding with electrons in the core.

Because they spend so much time bumping into electrons and changing the direction in which they are moving, it takes about 170 thousand years for photons to get from the sun's core to the solar surface. This is about the length of time that has elapsed between the appearance of cavemen on the Earth and now.

Once outside the sun, they zip through space to arrive at the Earth only 8 minutes later.


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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

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