Shop Windows to the Universe

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 - Evolution of the Solar System

This shows four images of Titan's surface taken from the Hubble Space Telescope.
Click on image for full size
NASA/Hubble Space Telescope

The cooler temperatures also influenced why the icy moons may be different at the different planets as the planets get further from the sun.

For example, Titan is the only icy moon to have an atmosphere that is big enough to be compared to a planets atmosphere. It is natural to ask how is this possible since Titan sits in the same position relative to Saturn that Ganymede sits relative to Jupiter? (Why doesn't Ganymede also have an atmosphere? Or Triton, a moon of Neptune?) The answer is that the nebula was colder in the vicinity of Saturn, than in the vicinity of the Galilean satellites. Evidently the nebula near Titan was cold enough to allow the nitrogen to condense to solid form.

The difference between Ganymede and Titan, is that Titan formed in a region cold enough for the condensation of nitrogen. The difference between Titan and Triton, is that Titan is presently in a region that is warm enough for the slow evaporation of nitrogen, causing Titan to be the only icy moon to have an atmosphere.

This is page 13 of 60

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!

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

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