X-rays get their name because when they were initially discovered, nobody knew what they were!

Did you know? You are probably most familiar with the use of X-rays in hospitals. When you get an `X-ray' done in a hospital, you are exposed for a very brief time to X-ray radiation. Your bones are quite good at absorbing X-rays, and so when the X-rays are measured on the other side of your body, there is a `shadow' where your skeleton is. Having an X-ray taken once in a while like most of us do is not bad for your body, but being exposed regularly can be a problem. This is why the person who takes your X-ray will hide out of the way while it is taken!

Are the Sun's X-rays not dangerous to us?

When a gas gets very hot, typically over one million degrees, it emits X-rays, that is why we can see the solar corona so well.

The X-rays from the Sun certainly are dangerous to us and we are lucky that we have an atmosphere around the Earth that prevents them reaching the ground. Atoms and molecules in the upper part of the atmosphere are very good at absorbing the X-ray radiation from the sun, keeping us protected.

Did you know? What about astronauts when they go for a space-walk? They are not protected by the Earth's atmosphere and so are exposed to X-rays. They do have some protection from their spacesuits, but this is not always enough. When a flare takes place on the Sun, the amount of X-ray radiation can be become very large and be very dangerous for the astronaut. Because of this, before a spacewalk is attempted, NASA finds out whether there is a possibility that a flare might take place. If there is, then the walk is postponed to a different time.