Atlas Image mosaic, covering 14.8Â´ Ã— 20.0Â´ on the sky, of the Trifid Nebula, aka Messier 20 and NGC 6514. The Trifid is only about 1.5 degrees northwest on the sky of the larger Lagoon Nebula (Messier 8) in the constellation Sagittarius, and is at a distance from us of 1.68 kpc (or 5477 light years), near the plane of our Milky Way Galaxy. It gets its name from its optical appearance, from three dark dust lanes that divide it. Like the Lagoon, much of the optical emission is dominated by the red light from hydrogen, forming an "H II region" of ionized gas around the bright small cluster of hot stars just to the southeast of the image center; the rest of the emission is reflected blue light from these hot stars, primarily from the brightest one, HD 164492A. In the near-infrared we can see through much of the obscuring dust in the Trifid, including the name-giving dust lanes, but still see much of the bluish light reflected by the dust. In the 2MASS image, much of the dark dust is still seen, but also many more stars than are seen optically. The Trifid is less than 1 million years old, and young, massive still-forming stellar objects can be seen as well. Visit the Trifid and other Messier objects in the 2MASSier Object Gallery. Image mosaic by E. Kopan (IPAC).