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Science, Evolution, and Creationism, by the National Academies, focuses on teaching evolution in today's classrooms. Check out the other publications in our online store.

ExploraTour: A Peek into the Lives of the Stars


Burnt Out Stars

There are also some very peculiar objects out there.

White dwarfs are the hot cores of stars that have blown away their outer layers. They are about the same size as the Earth.

Neutron stars are the cores of stars that have been compressed to a very small size by gravity and are cooling off slowly. They are barely as large as a small town.

Black holes are the stangest object in space. They are the core of stars that gravity has compressed down so small that nothing can escape not even light. They are even smaller than neutron stars.

These former stars have densities ranging from a million to a trillion times the density of the sun and more. Just to give you some idea of how incredible this really is let's look at the difference in density between air and solid rock. Let's pick gold for example. Gold is 16 thousand times more dense than air. So the change in density between the sun and a white dwarf or neutron star is more than the difference between air and rock!

The Why of It

The burning question is why? Why are stars born in such a wide variety of sizes and colors? Are there limits on how large or how small a star can be? How do normal stars change into black holes and neutron stars? And how do we know what we know?

Shop Windows to the Universe Science Store!

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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Cool It! Game

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 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 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