Hi all,
Sorry to hear that conditions weren't favourable for observing. I spoke with Rod on the phone and the phenomenon you guys experienced is known as "air glow". Where the sky is clear and conditions should be great, but it doesn't really get as dark as it should and the sky has a "glow" to it.
This can occur for several reasons but one of the more common is:-
Free molecules of Nitrogen (N2) and Oxygen (O2) are dissassociated from the parent atoms by solar activity in the upper atmosphere. These free molecules then re-combine to form Nitric Oxide (NO) and in the chemical reaction that takes place a photon is emitted. Air Glow only occurs under a special set and combination of atmospheric, chemical and solar phenomena. It is not all that uncommon.
We had excellent conditions at Wiruna (Ilford) seeing wasn't great but transparency was superb. Air glow certainly wasn't an issue. You know conditions have to be good when I pack the scope up because the sun is starting to reflect off the stainless steel bolts in the mirror cell
Andrew Murrell, our Texan friend Van Robinson and myself did an "allnighter", sharing the views in the 18" and 25" Obsessions. Gary Kopff from Wildcard crashed about 3 am. A memorable nights observing was had by all.
CS-John B
