Thanks for your insights; Amplelight. I think the best argument that it is not an impact is just that there are no other reports of anyone capturing it. There were a huge number of cameras focused on the moon at the time, with far more power and sophistication. I see NASA has a lunar meteorite observation program, but they apparently only image 10-15 days out of the lunar cycle, during the large shadow phases; so maybe they weren’t running at the time, what would have otherwise been a full moon, which is definitely not the time to be looking! Might see what they have to say about this.

And in considering the other obvious possibilities, I did check www.heavensabove.com for satellites that may have been able to occult the moon at that time, and found none close. Of course, could have been unlisted; but with a five second exposure, it is almost impossible for a satellite to not have left a noticeable star trail. The same would be true of a plane (there are many that fly over from the west here), but a plane’s lights would have been obvious in that long of an exposure. And could have been an owl or bat, but they typically stay pretty close to the ground; and if they did catch some light to be seen, it would have most likely been from terrestrial illumination and not the orange-red of the atmosphere out on the eclipsed moon. Maybe it was a cosmic ray through the camera sensor; but it wasn’t saturated.

As far as an impact being far-fetched, to put some scale on things, consider that we are not talking about resolution or resolving power, but just “energy in the bucket” when it comes to the camera pixels. That is, each pixel represents about a 3 mile square of the surface of the moon. But it doesn’t take a 3-mile impact to affect that pixel’s value... If you divide the pixel into say a 10 x 10 grid, then an impact in just 1 of those 100 “sub-pixels”, at 100x times the brightness of the rest, will effectively double the brightness of the entire camera pixel. As I recall, the suspect pixels are about 2x as bright as those nearby.

Of course, this is an unrealistic simplification, as diffraction of the optical system would spread any such “sub-pixel” event before even reaching the camera pixel; most likely spreading it into adjacent pixels as well. In round numbers, the diffraction limit for this f/6.3 set-up at 0.5 um green wavelength would be 1.22*(.5 um)*(6.3) = 3.84 um, which is essentially the same as the 3.9 um size of the D5300 DX-sensor camera pixels (as you would expect a well-engineered Nikon optic to be, wide-open). And at 0.6 um in the red wavelengths of the eclipse, the limit would be 4.6 um, larger than the pixel size; so “spilling” into adjacent pixels would always occur, no matter how small the impact site on the moon.

And now you’ve got to consider the seeing, or atmospheric refraction over the 5 second exp

Posted by Kinley 2018-02-08 00:34:07

Can you save the image as a .tif or .png rather than .jpg? That way, you will avoid compression artifacts on the image and get a better idea of the nature of the bright spot. At present, the bright pixels are surrounded by dark ones, typical of .jpg compression at light/dark boundaries (although the inset pic in the third image doesnt show the dark halo so much).

I would imagine that if it were really a lunar impact, other observers/societies would have picked it up, so you could try asking other observers to closely check their images. I suspect its not lunar though, and certainly not a satellite, because in 5 seconds, a typical low Earth orbit satellite would move several times the Moons width (less than a second for ISS to cross the disk when its close to the observer). Posted by ozalba 2018-02-08 00:43:28

Hi Ozalba; I can certainly post a PNG or the huge RAW (NEF) file, but the magnified inset of the “impact” is the un-modified PNG data from the RAW (NEF). It has been JPG’d as part of the whole image, but shouldn’t be greatly affected by the JPG compression, as the original pixels are now groups of 16 pixels in the higher magnification crop image (and JPG quality was set to “12” (the max) in Photoshop). The background image is sharpened, so it begins to show flaws at the higher magnification, especially around the “impact”, which is over-sharpened to white saturation and some dark area around it. I will look at it some more tomorrow and post an unmodified PNG. Posted by Kinley 2018-02-08 02:32:26

@amplelight
There is no gravity on the moon what kind of nonsense is this? The moon is a giant sphere of rock, weighing some 7 x 10^22 kg. Plenty of gravity.
More simply put, how else did you think the astronauts hopped around on there? If it wasnt gravity pulling them down, then why after a single hop did they not fly off?
How do you think the moon stays together as a sphere?
Where do you think tides here on earth come from?
Of course the moon has gravity!!
You CAN see impacts on the moon, and you dont need a flipping house for it to happen. https://www.youtube.com/watch?v=C8fe58ROYG0
The main reason we dont see many impacts is because the moon is facing us. Any incoming stuff either hits the other side of the moon, facing away from us, or flies past the moon, and hits the Earth. Only rarely will stuff get swung around to our side of the moon.
It very well could be a meteorite, but it could also be a dead pixel showing up 1 frame.
Id go with meteorite. Posted by MaxMallon 2018-02-08 16:36:38

Be careful what you call nonsense, MaxMallon.

You said Any incoming stuff either hits the other side of the moon, facing away from us, or flies past the moon, and hits the Earth. Only rarely will stuff get swung around to our side of the moon. It very well could be a meteorite, but it could also be a dead pixel showing up 1 frame.
Id go with meteorite.

You seem to be suggesting that Earth is a big shield, preventing almost everything from impacting the lunar nearside. Think about it in terms of the apparent size of Earth from the Moon: being four times the Moons diameter, Earth will be about 2° across. The visible hemisphere of sky is 180° across, so ignoring spherical trigonometry that may come into play, Earth covers about (2^2)/(180^2) of the lunar sky, or about 0.01%; that leaves a lot of sky for impacts to arrive from.

Yes, if an asteroid is heading directly towards the Moon, from the behind Earth, then Earths gravity may deflect it away from the Moon, but equally, an asteroid on a near-miss path may be deflected into an impacting trajectory.

Also, dead pixels tend to remain dead. A random bright spot could possibly be a cosmic ray event, although I wouldnt expect theres many of them at ground level. Posted by ozalba 2018-02-08 23:48:58

Here are links to 1080x1080 cropped, un-processed, 16-bit/ch PNG files from original NEFs, before, during, and after the possible imapact:

www.FredKinley.comPNG20180131_053704_DSC_4172_crop_1080x1080.png
www.FredKinley.comPNG20180131_053923_DSC_4173_crop_1080x1080.png
www.FredKinley.comPNG20180131_053949_DSC_4174_crop_1080x1080.png

This NASA website explains their lunar meteorite monitoring criteria, which among other things relies upon independent sightings from distant observation sites to confirm impacts:

https://www.nasa.gov/centers/marshall/news/lunar/overview.html

What I was hoping for when posting this was that someone else may have seen or recorded it... no such luck it appears.

Posted by Kinley 2018-02-09 03:19:48

Links above need / slashes each side of PNG; I dont know to post links here! Posted by Kinley 2018-02-09 03:22:23

Try again:

www.FredKinley.com/PNG/20180131_053704_DSC_4172_crop_1080x1080.png
www.FredKinley.com/PNG/20180131_053923_DSC_4173_crop_1080x1080.png
www.FredKinley.com/PNG/20180131_053949_DSC_4174_crop_1080x1080.png

Posted by Kinley 2018-02-09 03:27:10

OK, got those images up now (the comment system here is a little annoying: it strips out some characters, such as apostrophes; maybe it strips out the slashes too).

I reckon its either an instrumental glitch or a cosmic ray event. Simply looking at the size of the star at lower left, and comparing it with the flash, unless the seeing improved at that instant, I doubt its an image of anything occurring on the Moon.

The mystery remains. Posted by ozalba 2018-02-11 21:17:29

Thanks Olzaba; thats an excellent point. I was thinking it was probably on the order of a 1-second event, not averaged over the seeing for 5 seconds like the rest of the image. But if an impact, it most likely would have been a several-second event at least. Still not seeing another other reports, so I think its case closed as being anything interesting. Posted by Kinley 2018-02-13 14:05:16

Thanks Olzaba; thats an excellent point. I was thinking it was probably on the order of a 1-second event, not averaged over the seeing for 5 seconds like the rest of the image... But if an impact, it most likely would have been a several-second event at least. Still not seeing other other reports, so I think its pretty-much case closed as being anything interesting. Posted by Kinley 2018-02-13 14:06:45