Being a newcomer to astronomy, I tend to spend a lot of very cold nights in the back garden, pointing my Tasco 4.5inch reflector towards anything that looks remotely interesting. Most of the time, owing to the optics, or lack thereof, things resolve themselves into a small white dot, jumping around in the field of view.
I find that one thing the Tasco is very good at is observing the moon. I've upgraded two of the supplied eyepieces to Plossl 12.5mm and 7.5mm. which improve the resolution of Lunar observations tenfold.
As a result of this, on December the 27th, I was enjoying a quiet hour just wandering around the surface of the moon. I'm still at the 'Ooh! Ahh!' stage with this stuff and don't know the moon well enough to identify anything but the most prominent features. I found a rather large crater in darkness with the terminator just to the North/West (in the eyepiece) and a central peak, which showed up nicely. I centered it up in the F.O.V. and was quietly 'Oohing and Ahhing' to myself when I noticed a flash of light which seemed to come from the darkness at the bottom of the crater. I thought that I'd caught an aircraft beacon as it flew overhead (we're on the downwind leg to Glasgow Airport) and looked up to spot the offender. Nothing in sight, I looked back into the eyepiece and a few minutes later, spotted another flash from the same spot. This one lasted for around four seconds! Thoroughly confused now, I continued with eye glued to the Plossl and was rewarded with a two second flash from the same area around a minute later. The flashes looked like a small point of brightening, white light, which faded just as quickly as it came. It didn't appear to light up the area of the crater around it.
I've tried to find the crater on moon maps but the nearest I can locate it is somewhere in the Sinus Iridum area. What always confuses me as a neophyte, is the fact that the view in the eyepiece is reversed and it doesn't help that I don't have a really good map of the moon.
I did a bit of digging on the Web and found quite a few of these things have been seen over the years. They're known as L.T.P. or Lunar Transient Phenomena. Bright flashes of light, mists or even red glows seen in the darkness. There's even a group of astronomers who patrol the Lunar surface regularly trying to spot L.T.P. Theories vary as to what they are, from sheer quartz faces reflecting sunlight through to Top Secret Moonbases. (Ours or E.T. I can't say for sure.)
The most sensible, at least to my mind, explanation comes from Russell Cockman in reply to an e-mail I sent him, 'The moon is not a dead place and remains under constant bombardment by meteors. During the Leonid storms in 1999 and 2001 a number of flashes were recorded on the dark part of the moon attributed to meteor impacts.'
I'll be watching the dark, a bit more closely from now on.
Lessons learned from this encounter?
- Get a good moon map as soon as possible.
- Always take a notepad and record exact time and date of observation with an accompanying sketch.
- Get a good hat to keep my ears warm!!