The Omega Nebula, also known as the Swan Nebula, or M17, was discovered in 1745 by Swiss astronomer Jean-Philippe Loys de Chéseaux. This nebula is 5500 light-years away from Earth in the constellation Sagittarius. It's one of the largest star-forming regions in the Milky Way. It appears in the northern sky and can best be seen through binoculars during the winter months.