When we look into the night sky, we sometimes see unexpected objects as well as planets and stars.
We can see even more in the night sky with a telescope. Telescopes collect more light than our
eyes and can magnify the images they collect. This means they can see further into space and get
more detailed images. Telescopes can be placed either on the ground or on satellites. The images
collected by ground-based telescopes tend to be quite fuzzy because the Earth's atmosphere scatters
the light. It is however very expensive to put telescopes on satellites in space.
Telescopes can be designed to detect any type of electromagnetic wave. This advance in technology
has allowed astronmers to generate images of objects in space from the infra-red, radiowaves, X-rays
and any other electromagnetic waves they emit. Astronomers have learnt a great deal about the
Universe from these images.However, not all electromagnetic waves can penetrate the Earth's
atmosphere. This means telescopes that detect certain electromagnetic waves must be placed in space.