Of all the wonderful things you can do with your camera at night (like light painting), photographing star trails is one of the coolest (see photo above).
Photographers can enter online by visiting www.nmm.ac.uk/astrophoto, where full competition rules and some top tips on photographing everything from star trails to deep space objects are also available.
Wide aperture settings allow for shorter exposure times and a better balance between the star trails and the night sky and other elements in the scene.
