... Credit Copyright: Steve Mazlin , Jim Misti Explanation: These three bright nebulae are often featured in telescopic tours of the constellation Sagittarius and the crowded starfields of the central Milky Way . In fact, 18th century cosmic tourist Charles Messier cataloged two of them; M8, the nebula below and right of center, and colorful M20 at the upper right. The third, NGC 6559 , is left of M8, separated from the the larger nebula by a dark dust lane. ... NASA Official: Jay Norris. ...