User login


Earth's atmosphere from the
International Space Station (ISS)
Credit: NASA

Some planets and moons are covered in a thin layer of gases, called an Atmosphere, which is held in place by the gravity of the body. This means that small planets and moons, which have small gravitational pulls, tend not to have them.

The higher you get from the surface of the planet the thinner the atmosphere becomes, which is why it becomes harder to breathe when you're on top of a mountain. It's also why we put telescopes on mountains, as the atmosphere can blur our images by an effect we call astronomical seeing.

On Earth our atmosphere protects us from harmful radiation from the Sun. It also provides us with air to breathe, but not all atmospheres are the same. In fact, the Earth's atmosphere, which is mostly nitrogen and oxygen, is the only one we have found that we can breathe. On other planets, with different atmospheres, perhaps life has evolved to 'breathe' other gases.


Please note that over the weekend of the 26-28th May 2017 we will be switching over to our brand new website - during this time there may be periods where the site is difficult to access, and users will be unable to request observations from the telescope. Please bear with us during this time. All should be back up and running by the 29th May 2017.