The Moon almost ruined this photograph. During late March and early April 1997, Comet Hale-Bopp [ http://www.jpl.nasa…] passed nearly in front of the Andromeda Galaxy [ http://antwrp.gsfc.…]. Here the Great Comet of 1997 [ http://cometography…] and the Great Galaxy in Andromeda [ http://www.seds.org…] were photographed together [ http://antwrp.gsfc.…] on 1997 March 24th. The problem was the brightness of the Moon [ http://antwrp.gsfc.…]. The Moon [ http://www.seds.org…] was full that night and so bright that long exposures meant to capture the tails of Hale-Bopp [ http://antwrp.gsfc.…] and the disk of M31 [ http://antwrp.gsfc.…] would capture instead only moonlight reflected off the Earth's atmosphere. By the time the Moon would set, this opportunity would be gone. That's why this picture was taken during a total lunar eclipse [ http://antwrp.gsfc.…].
Explanation
The Moon almost ruined this photograph. During late March and early April 1997, Comet Hale-Bopp [ http://www.jpl.nasa…] passed nearly in front of the Andromeda Galaxy [ http://antwrp.gsfc.…]. Here the Great Comet of 1997 [ http://cometography…] and the Great Galaxy in Andromeda [ http://www.seds.org…] were photographed together [ http://antwrp.gsfc.…] on 1997 March 24th. The problem was the brightness of the Moon [ http://antwrp.gsfc.…]. The Moon [ http://www.seds.org…] was full that night and so bright that long exposures meant to capture the tails of Hale-Bopp [ http://antwrp.gsfc.…] and the disk of M31 [ http://antwrp.gsfc.…] would capture instead only moonlight reflected off the Earth's atmosphere. By the time the Moon would set, this opportunity would be gone. That's why this picture was taken during a total lunar eclipse [ http://antwrp.gsfc.…].
