Transient Lunar Phenomena (maybe) and a shot of the Moon

[Thefatkitty]

Hey everyone,hope things are well with you and yours

Last night I was going to do some observing, as it was clear. But there's a problem with that. The only time it gets clear here in the winter is when it's cold, and last night was no exception, with a temperature of -20C (-5F).

Well, I'm not getting any younger, and I find sitting out for an extended period of time at that temperature to be rather uncomfortable now. The Moon is 6 days past new, so maybe I'll take out my C80-HD, Canon 550D and take some shots. That's only 5 minutes.

I put the scope out at about 8PM to let it cool off. I know, fracs supposedly don't need cool down time like a reflector, but I have to think going from room temps to a difference of 75F or 40C lower might cause some tube currents. I put it in the shed on a milk crate and take the two caps off. This, to me, lets the warm air escape out the back and bring the whole scope and outside temps to the same.

I went out at 8:30 and set it up with the camera and my CG4 mount. I got the Moon in focus, and had a look through the viewfinder of the camera.

I'm not sure where to start with what I saw. I believe it was on the edge of Fracastorious crater (@Makuser Marshall , you would know! ). I saw what looked like a very large intermittently blinking light.

The view with the camera's viewfinder I would equate as similar to looking through this scope with a 25-30mm lens. My mount is manual, and I watched as the Moon drifted through the viewfinder with the light being really intense, vanishing, a slight glow again, then really intense again... There was one time where it was blinking for a brief period like an aircraft light. As I said, the duration of each event changed over the course of watching it. I looked at this for almost two minutes; I had to adjust the RA knob a couple of times to keep this view in focus.

Then it just stopped! That was it, no more light show for Mark...

Of course, after the fact, I kicked myself for not taking a video of it. Still, I'm happy I saw it!

What I think is this (and I could be so wrong): I caught a rare moment when the Moon was at a position relative to where I am and the Sun to reflect light off the edge of a crater at the terminator. When the Moon is waxing (new to full) you often see craters emerging on the terminator over the course of time. What I don't get is, what is so reflective on the Moon to cause this?

I looked it up on the net; thinking maybe I had seen a Transient Lunar Phenomena event. It seems probable; I'm not too sure, but it's the closest explanation I have.


After that amazement, I took some shots and went back inside with everything. I processed 15 shots at ISO 800 and 1/200th sec exp. I stacked the best 75% in PIPP, AS3, with a bit of tweaking in ImPPG and Adobe Photoshop CS6. Yes, CS6.
I'm running Linux Mint 20.2 and that what works. Here's a screenshot of my desktop:

A few programs are Linux (Stellarium, Gimp, RAWTherapee), but the others are Windows programs; PIPP, AS3, etc. I run those under WINE using a front end for it called PlayOnLinux. One day I might make a post about how to get all this to work if anyone is interested


This is the stacked image of the Moon last night, Jan. 7th, 2022.

And this is the exact spot I saw the "flashing light". It's still bright...

According to Stellarium, the Moon was at 32.6% illumination. However, I feel that unless the Moon is at the exact same RA/Dec coordinates as well as many other coordinates I don't even understand, this was probably a rare event for me.

Well, I've had a busy day learning new things on here, making my family put up with me and the like Probably time for bed soon.

Have a great and hopefully clear night all!!

[Lady Fraktor]

Interesting observation Mark.
It could well be light reflecting through valleys/ mountain tops.
Possibly you had a glint off of one of the many orbiters?

[Makuser]

Hi Mark. It looks like were able to have some observing fun even with the cold weather. Sorry to get this to you late but this has been a busy day until now. Below is the area that your are referring to in your image.

The large crater with central peaks below your arrow is Piccolomini and running above it is the Altai Scarp which is part of the outer Nectaris Basin. The Altai Scarp is a dramatic 3.5 to 4 km high cliff. And as it continues it becomes a weaker and more broken scarp. A low angle sun could produce the bright effects that you saw through a reflection from a tall scarp peak. Thanks for your nice read report Mark and I hope this helps.

[WilliamPaolini]

Very cool that possibly saw those elusive TLPs!! I've always wanted to catch one. Was there any color to the light? Also, did it remain stationary relative to the backdrop of the lunar surface the entire time? Were the blinking intervals consistent or did they vary?

[Thefatkitty]

Interesting observation Mark.
It could well be light reflecting through valleys/ mountain tops.
Possibly you had a glint off of one of the many orbiters?

Hi Gabrielle, yeah, I was thinking an orbiter as well, but the flashes were really quite large in relation to the Moon. But, I can't say for sure, could the LRO for example glint that much? I don't know enough to say...
It was really cool though!

Hi Mark. It looks like were able to have some observing fun even with the cold weather. Sorry to get this to you late but this has been a busy day until now. Below is the area that your are referring to in your image.
The large crater with central peaks below your arrow is Piccolomini and running above it is the Altai Scarp which is part of the outer Nectaris Basin. The Altai Scarp is a dramatic 3.5 to 4 km high cliff. And as it continues it becomes a weaker and more broken scarp. A low angle sun could produce the bright effects that you saw through a reflection from a tall scarp peak. Thanks for your nice read report Mark and I hope this helps.

Marshall, you are the man! Your knowledge of our nearest celestial neighbour always amazes me!
Thanks so much for the info; I'm wondering if it was indeed sunlight bouncing off the cliffs, especially if they vary in height. It did vary in intensity and brightness.
Thanks again, and what book is that you have, if I may ask?

Very cool that possibly saw those elusive TLPs!! I've always wanted to catch one. Was there any color to the light? Also, did it remain stationary relative to the backdrop of the lunar surface the entire time? Were the blinking intervals consistent or did they vary?

Thanks Bill, and well, I'm not too sure if it was a TLP, but it was definitely something I've never seen on the Moon before!

There was no colour, just white. It really looked like sunlight being reflected off a mirror. As well, when I first spotted it, it was bright, then dimmed, disappeared for a bit, winked on and off a few times, surged in brightness, then back to dim again...

No repetition to the pattern; it was all very random. There were a few seconds where it looked like a literal beacon on the Moon, it was so prominent.

As for it being stationary in relation to the Moon, yes it indeed was.

Again, kicking myself for not turning on the camera...

[Bigzmey]

Fun observation Mark! It pays to look up, never know what you will see.

-20C? Hah, you would not catch me coming out at 0 C.

[jrkirkham]

Thanks for the great report, Mark. I love the mystery and excitement it generated. I always wanted to see a TLP of some sort.

[Greenman]

Nice report Mark, yep I agree with Marshall on this - great to observe it. Perseverance pays even at -20.

[WilliamPaolini]

Here's where your arrow is pointing. Lat/Lon -19.36105 18.122289.
https://quickmap.lroc.asu.edu/?extent=- ... AXwF1SizSg

You can zoom in much closer with the wheel on your mouse. Put those Lat/Lon numbers in the search box on the top left to anchor a cross hair on the target zone.

The Altai Scarp ridge which is lit up in your image looks to have a max altitude of about 3600 meters. Some of the highlands in the dark region from the illuminated ridge towards your arrowhead are however higher at about 4400 meters at approx -18.95672 19.28293. So maybe some glints off those it not a TLP (FYI there is a line tool in that app that lets you examine the terrain heights).

[Thefatkitty]

Fun observation Mark! It pays to look up, never know what you will see.

-20C? Hah, you would not catch me coming out at 0 C.

Thanks Andrey, it was certainly a never-before-seen-by-me event!

Yeah, it was cold... how low do the temps get where you are? I understand the desert can be cold at night; just curious

Thanks for the great report, Mark. I love the mystery and excitement it generated. I always wanted to see a TLP of some sort.

Hi Rob and thanks! Still not sure if it was a TLP, but I couldn't (and still can't) get over how bright it was! I'll literally be keeping an eye out for this again!

Nice report Mark, yep I agree with Marshall on this - great to observe it. Perseverance pays even at -20.

Thanks Tony -20C, at least it wasn't windy. Yup, best observation in a long time!
Hope all is well with you and yours; great images on the weekend as well!

Here's where your arrow is pointing. Lat/Lon -19.36105 18.122289.
https://quickmap.lroc.asu.edu/?extent=- ... AXwF1SizSg

You can zoom in much closer with the wheel on your mouse. Put those Lat/Lon numbers in the search box on the top left to anchor a cross hair on the target zone.

The Altai Scarp ridge which is lit up in your image looks to have a max altitude of about 3600 meters. Some of the highlands in the dark region from the illuminated ridge towards your arrowhead are however higher at about 4400 meters at approx -18.95672 19.28293. So maybe some glints off those it not a TLP (FYI there is a line tool in that app that lets you examine the terrain heights).

Wow, thanks for the info and time spent, Bill! What a great site; I never knew.
In looking at it I can see that the varying height would explain the random surges in brightness and dimness; if it was indeed a reflection from a ridge. I really think it was. I still can't get over the intensity of it at times.

I appreciate the info; that was a big help to me
All the best to you and yours!

[notFritzArgelander]

An interesting observation! During one of the recent eclipses of the Moon I "thought" I saw a bright flash and dismissed it. Later I read that many had seen a meteor strike on the Moon. Here's to keeping looking up!

[Makuser]

Hi Mark. Book? It is really books and this all didn't happen overnight. I got back into astronomy for the second time in 1974 with a 60mm achro refractor on cheap mount. But I was amazed at what could be seen on the moon with this rig. I know, the moon is big, bright, and close. I used to take visual moon walks almost every clear night. Selene has been an ever lasting compassion with me ever since and including my third and current astronomy return in 2009. The scan that I posted was from the latest book, 21st Century Atlas of the Moon.

You can see that I wore out the oldest lunar map years ago and that Chuck Wood has been my lunar guru and also contributing editor to Sky & Telescope magazine.
https://www.psi.edu/about/staffpage/cwood
And I want to thank WilliamPaolini (Bill) for his most helpful lunar identification link.
Finally, I wanted to mention all of the talented folks on here. I was thinking about astroavani for his excellent lunar images and detailed information and last night he posted a beautiful lunar image of this very region taken with his Celestron 14" Edge HD telescope and also provided a great commentary of information. I want to include the link here for any who missed his post.
viewtopic.php?f=67&t=22686
As a lunartic, I am really enjoying this thread and sometimes it is all about the "play of light" and/or our mind's conception of what we think we see.