On average, people in the U.S.A. are exposed to about 3.6 milliSieverts of radiation each year.
Click on image for full size
Windows to the Universe original artwork using data from the National Council on Radiation Protection and Measurements.
Radiation comes in two basic types: electromagnetic
by photons, and particle
radiation consisting of
electrons, protons, alpha particles, and so forth.
transmitted as photons,
includes everything from relatively benign radio
dangerous and powerful X-rays and gamma
Energy levels across the electromagnetic
inversely with wavelength.
Particle radiation involves
fast-moving sub-atomic particles, such as electrons, protons,
and nuclei (ions) of Helium and heavier elements.
Exposure to too much
radiation of various types can be harmful to humans and other living
things. Radiation can also fry the electronics in spacecraft, disabling them.
Shop Windows to the Universe Science Store!
Learn about Earth and space science, and have fun while doing it! The games
section of our online store
includes a climate change card game
and the Traveling Nitrogen game
You might also be interested in:
Electromagnetic radiation is the result of oscillating electric and magnetic fields. The wave of energy generated by such vibrations moves through space at the speed of light. And well it should... for...more
One main type of radiation, particle radiation, is the result of subatomic particles hurtling at tremendous speeds. Protons, cosmic rays, and alpha and beta particles are some of the most common types...more
Light is very strange. Sometimes it is best to think of light as a series of waves. At other times, it is useful to think of light as a swarm of particles. When we think of light as particles, we call...more
Radio waves are a type of electromagnetic radiation. A radio wave has a much longer wavelength than does visible light. We use radio waves extensively for communications. Radio waves have wavelengths as...more
Whether or not a cell can repair itself after being damaged by radiation depends on the type of damage to the cell's DNA. Type of Damage Prospects for DNA Repair Single strand break in the DNA Can usually...more
Radiation can damage electronic circuits and it can cause electronics to malfunction. Radiation can degrade the semiconductor materials used in electronics, reducing the useful lifetime of the electronics....more
Some materials are radioactive. They emit radiation. When an atom of a radioactive substance emits radiation, it is transformed to a new type of atom. This process is called radioactive decay. There are...more