The Orion Nebula, also known as the Great Nebula, is probably the most famous of all nebulas. It is over 1,000 light-years away, with a diameter of 30 light-years. It is shining because of the hot young stars at its Earth-turned edge. There are four main stars in the group, nicknamed the Trapezium because of the way in which the four are arranged. It is fascinating to observe, and predictably, it is a favourite target for astronomical photographers.