The Hydrogen Clouds of M33 . ... Lemmon SkyCenter , U. Arizona Explanation: Gorgeous spiral galaxy M33 seems to have more than its fair share of glowing hydrogen gas. ... To enhance this image, broadband data was used to produce a color view of the galaxy and combined with narrowband data recorded through a hydrogen-alpha filter, transmitting the light of the strongest hydrogen emission line . ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ...