The higher energy waves above UV radiation include x-rays and gamma rays. The sun does emit these rays, but thankfully our atmosphere doesn’t let any of them through to the earth! You are probably familiar with x-rays; almost everyone has had them done at the doctor’s or dentist’s office. X-rays can go through your body, but are absorbed by your bones and teeth, so they are used to take pictures of your bones. A lead shield is used to protect other areas of your body, as x-rays don’t go through lead. X-ray telescopes are used in space exploration as well.
Gamma rays are the highest energy radiation. They can go through lead and concrete, and will kill living cells. They are dangerous, and when people speak of “radiation”, they are usually speaking of these rays. Gamma rays are emitted in nuclear explosions, and nuclear power plants take great precautions to contain them. They are put to use, however, in medicine. When people get radiation treatment for cancer, they are exposed to gamma rays, which kill the cancerous cells. `
Gamma-ray bursts (GRBs) are powerful flashes of energetic gamma-rays lasting from less than a second to several minutes. They release a tremendous amount of energy in this short time making them the most powerful events in the Universe. They are thought to be mostly associated with the explosion of stars that collapse into black holes. In the explosion, two jets of very fast-moving material are ejected, as depicted in this artist’s illustration. If a jet happens to be aimed at Earth, we see a brief but powerful gamma-ray burst.
