... Next huge filaments of dark interstellar dust run across the image and block the light from millions of more stars yet further across our Galaxy . The bright red region on the left is the Omega Nebula , an emission nebula of mostly hot hydrogen gas also known as M17 . A small bright grouping of stars near the image center is the open cluster M18 , while the long bright streak of stars just right of center is M24 . ... NASA Web Site Statements, Warnings, and Disclaimers . ...