NGC 6888, also known as the Crescent Nebula, is a bright emission nebula located in the constellation Cygnus. It is approximately 5,000 light-years away from Earth and spans about 25 light-years across. The nebula is formed from the gas and dust ejected by a massive star, HD 192163, which is in the process of dying. The Crescent Nebula is notable for its distinct crescent shape, which is created by the interaction of stellar winds from the central star with the surrounding material. This nebula is a popular target for amateur astronomers and astrophotographers due to its striking appearance and vibrant colors.