Trifid Nebula, 1874. Also known as M20 and NGC 6514, it consists of an emission nebula, a reflection nebula, and a dark nebula (Barnard 85) which forms the three prominent dust lanes. The H II region emission nebula consists of interstellar hydrogen that is being ionized by radiation from hot young stars. This nebulae is around 5400 light years from Earth in the constellation of Sagittarius. Observed from Harvard College Observatory, Cambridge, Massachusetts, USA, by US astronomer Joseph Winlock.