According to astronomer Dana Thompson, an elusive lunar sunrise effect can be seen for a brief period forming an illuminated "X" by several intersecting crater walls. Below are some email excerpts from Mr. Thompson:
As the terminator slowly moves over the crater Werner, light of the lunar sunrise begins to illuminates some of the highest lunar topography in the region which stands between the craters La Caille, Purbach, and Blanchinus. The "X" feature is fully formed in about two hours and stands out in obvious contrast to the dark side of the terminator. This
unique lunar event lasts for about another two hours before being total surrounded by light from the lunar sunrise. At this time the lower topography of the area is illuminated as well and the "X" on the moon begins its transition back into hiding on the surface of the fully illuminated lunar landscape.
The following times are best guess estimates to start observing so you don’t miss it:
March 25/26, 2007
March 26, 2007 @ 02:23 UT, co-long = 357, Werner sun alt = .9
May 23/24, 2007
May 24, 2007 @ 04:34 UT, co-long = 357, Werner sun alt = .4
July 21/22, 2007
July 22, 2007 @ 02:32 UT, co-long = 357, Werner sun alt = .7
September 18/19, 2007
September 18, 2007 @ 23:27 UT, co-long = 356, Werner sun alt = .5
Nov 16/17, 2007
November 17, 2007 @ 01:44 UT, co-long = 356, Werner sun alt = 1.0
Sounds like a good challenge that doesn't require dark skies.
Tom
As the terminator slowly moves over the crater Werner, light of the lunar sunrise begins to illuminates some of the highest lunar topography in the region which stands between the craters La Caille, Purbach, and Blanchinus. The "X" feature is fully formed in about two hours and stands out in obvious contrast to the dark side of the terminator. This
unique lunar event lasts for about another two hours before being total surrounded by light from the lunar sunrise. At this time the lower topography of the area is illuminated as well and the "X" on the moon begins its transition back into hiding on the surface of the fully illuminated lunar landscape.
The following times are best guess estimates to start observing so you don’t miss it:
March 25/26, 2007
March 26, 2007 @ 02:23 UT, co-long = 357, Werner sun alt = .9
May 23/24, 2007
May 24, 2007 @ 04:34 UT, co-long = 357, Werner sun alt = .4
July 21/22, 2007
July 22, 2007 @ 02:32 UT, co-long = 357, Werner sun alt = .7
September 18/19, 2007
September 18, 2007 @ 23:27 UT, co-long = 356, Werner sun alt = .5
Nov 16/17, 2007
November 17, 2007 @ 01:44 UT, co-long = 356, Werner sun alt = 1.0
Sounds like a good challenge that doesn't require dark skies.
Tom
Attached Image:
