... Wisps of the Veil Nebula . ... These wisps of gas are all that remain visible of a Milky Way star. Many thousands of years ago that star exploded in a supernova leaving the Veil Nebula, pictured above. ... Molecular Cloud Barnard 68 . ... Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. ... These gas clouds leave numerous absorption lines in a distant quasar's spectra, together called the Lyman-alpha forest. ...