A schematic view of the Cherenkov effect.
Windows to the Universe original image
If you are sitting in the dentist's chair and they decide to X-ray your teeth, they put a big shield over you for protection. Why? Because they need to shield you from 'radiation'.
Radiation comes in many forms. Radiation is another term for light, as in "ultraviolet radiation". Visible light, infrared, and X-rays are all other names for radiation at specific wavelengths. Radiation is also generated by charged particles, especially when they are moving very fast.
One place in nature where electrons (one of the charged particles that make up an atom
) can move very fast is inside a planet's magnetosphere. Earth
, and even the little moon Ganymede
, all are surrounded by belts of radiation called 'radiation belts', which are high above the surface, but still bound to the planet by the force of gravity.
Radiation can kill you. Radiation can also have a pretty serious impact
on hardware that gets exposed. The main reason radiation is harmful is that it causes little defects in material, from human skin to metals, and causes matter to break down. Radiation can also do good things, though, such as helping doctors to image your body and determine what if something is wrong. Radiation can even cause new molecules
to form on the surface of Europa.
A special kind of radiation, called Cherenkov radiation
is illustrated in this drawing.
The US Nuclear Regulatory Agency defines the maximum permissible annual dose for an adult member of the public as 0.1 REM. About 600 REM = certain death. For comparison, a spacecraft in Jupiter's extreme radiation environment is exposed to 45,000 REM's per hour.
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:
The Earth's radiation belts are one component of the larger and more complex system called the magnetosphere. The radiation belts of the Earth are made up of energetic, electrically charged particles or...more
Jupiter's magnetosphere is a unique object in the solar system. It is the biggest object in the entire solar system. Not only is it big enough to contain all of Jupiter's moons, but the sun itself could...more
When the Galileo spacecraft flew by Ganymede, to everyone's surprise, it measured a very strong magnetic field for the first time near any moon. To generate a magnetic field, there must be conducting material...more
The picture to the left shows examples of the many amazing different surface features of Europa. Many exciting discoveries were made about Europa during the Galileo mission. The surface of Europa is unusual,...more
A satellite which has an atmosphere, such as Jupiter's moon Io, and which also is inside a magnetosphere (unlike the Earth's moon), will leave a cloud of particles behind as it orbits the planet. This...more
Jupiter's magnetosphere is very pointed and bullet-shaped, as shown in this picture, because of the nature of how it is created. The magnetosphere has many parts, such as the bow shock, magnetospheath,...more
Jupiter's magnetosphere is practically all plasmasphere. Jupiter's magnetosphere is filled with plasma. Most of the plasma comes from the donut-shaped cloud (torus) of material from Io. Besides ions and...more