The Lagoon Nebula in Three Colors . ... UNLP ), CTIO , NOAO , NSF Explanation: The bright Lagoon Nebula is home to a diverse array of astronomical objects. Particularly interesting sources include a bright open cluster of stars and several energetic star-forming regions . When viewed by eye, cluster light is dominated by an overall red glow that is caused by luminous hydrogen gas, while the dark filaments are caused by absorption by dense lanes of dust . ... NASA Official: Jay Norris. ...