View cloud cover over the UK in the latest satellite image from the Met Office

Astronomy for Beginners

Here’s where you’ll find observing guides, how-to articles and great astronomy hints and tips. Don’t forget to also check out our comprehensive astronomy dictionary.

Astronomy Dictionary
OIII filter

This is a special filter designed to let through a very specific wavelength of light emitted by oxygen in nebulae. It can help filter out light pollution and improves the view of objects such as planetary nebulae.

Spectral lines

A rainbow shows the small slice of the entire electromagnetic spectrum that humans can see. When astronomers use instruments to break down the light from a distant star or galaxy they also produce spectra. These contain signatures of the chemicals and molecules present in an object

Opposition

The position of a superior planet when it is opposite the Sun in the sky, as viewed from Earth.