Glossary : Ultraviolet Radiation
The energy range just beyond the violet end of visible light.
Although ultraviolet radiation constitutes only a small portion of the
total energy emitted from the sun, it is the major energy source for the
stratosphere and mesosphere, playing an important role in both energy
balance and chemical composition.
Most ultraviolet radiation is blocked by Earth's atmosphere, but some
solar ultraviolet gets through and helps plants to make foods and people to make vitamin D. Too much ultraviolet radiation can burn the
skin, cause skin cancer and eye problems, and hurt vegetation.
Shop Windows to the Universe Science Store!
Our online store
includes fun classroom activities
for you and your students. Issues of NESTA's quarterly journal, The Earth Scientist
are also full of classroom activities on different topics in Earth and space science!
You might also be interested in:
As we move out in the solar system, the planets get colder, and higher temperatures begin to be found deeper into the interior of the planet where, the pressure of overlying material becomes immense. Jupiter's...more
AU stands for Astronomical Units. It is an easy way to measure large distances in space. It is the distance between the Earth and the Sun, which is about 93 million miles. For really big distances, we...more
The solar wind is formed as the Sun's top layer blows off into space. It carries magnetic fields still attached to the Sun. Streams appear to flow into space as if they are spiraling out from the Sun,...more
For a planet to be affected by a blob of material being ejected by the sun, the planet must be in the path of the blob, as shown in this picture. The Earth and its magnetosphere are shown in the bottom...more
If someone says they saw an aurora, you might picture something like this. There is another type of aurora that we can't see. These aurora are called SAR arcs. The SAR stands for Stable Auroral Red. That...more
This figure shows the effect of the aurora on the atmosphere. When FAC's enter the atmosphere and create the aurora, they heat the atmosphere suddenly and abruptly. This creates an impulse which travels...more
This picture shows the flowing of particles into and out of the auroral zone, as Field-Aligned currents (FAC's) take at short-cut through the atmosphere. Some of the particles entering the auroral zone...more