Glossary : Ultraviolet Radiation
The energy range just beyond the violet end of the visible spectrum.
Although ultraviolet radiation makes up only about 5 percent of all energy from the sun, it is the major energy source for the
stratosphere and mesosphere, playing an important role in both en
balance and chemical composition.
Most ultraviolet radiation is blocked by Earth's atmosphere, but some
solar ultraviolet makes it through and aids in plant photosynthesis and helps
produce vitamin D in humans. Too much ultraviolet radiation can burn the
skin, cause skin cancer and cataracts, and damage vegetation.
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, as well as books
on science education!
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 a useful way to measure the distances in interplanetary space. It is the distance between the Earth and the Sun, which is about 93 million miles. For reference,...more
The solar wind is formed as the Sun's top layer blows off into space, carrying magnetic fields still attached to the Sun. Gusts form in the solar wind associated with violent events on the Sun. Particles...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
The aurora we are most familiar with is the polar aurora. This is what people are talking about when they say the northern or southern lights. But there are other less-known aurora, such as SAR arcs....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