Snake in the Dark . ... Credit Copyright: Gary Stevens Explanation: Dark nebulae snake across a gorgeous expanse of stars in this wide-field view toward the pronounceable constellation Ophiucus and the center of our Milky Way Galaxy. ... Unlike bright emission nebulae and star clusters, Barnard's nebulae are interstellar dark clouds of obscuring gas and dust. ... Many of Barnard's dark nebulae are themselves likely sites of future star formation. ... NASA Official: Jay Norris. ...