Anyone tried to capture meteor impacts on the moon during a New Moon?
What would it require?
Simpliest setup I can think of would be a tracking telescope with a HD motion sensing security camera.
A small bright flash should trigger a capture photo. What are the odds of capturing something in six hours?
You found the NASA links already, but this topic has been a conversation on CN a few times already-with some other good links and info.(more in the Lunar section)...
As to certain naysayer objections,
I delay in deconstructing them point-by-point for now,
although it makes me sad how often many posters pile-on on a subject they haven't acknowledge they've looked into themselves.
Mental experiments without information often end up with false conclusions because the info they form the premises with are lacking....
Of course as stated before (not to repeat again, but to give credit), the point is valid that the New Moon is due to orbital mechanics always near the Sun, so there are not a lot of night+New Moon over-the-horizon opportunities ..
But that is a minor point since one can adjust target recording days....
As to motion-sensing,
you are correct in principle that a set-up with auto-detect would make storage space and detection efforts easily.
However, there is some difficulty in the matter.
No consumer camera features (such as motion-detect) would offer reliable triggering.
Spatial resolution: The first challenging is to record realtime video >30fps with a camera pixel size-to optical focal length (while being bound by atmospheric seeing limits) so that your spatial resolution would capture an event that is more than a pixel in size....Of course, more major events (like the recent TLE capture) will need less than the smaller events.....Often this is in tandem with camera output resolution as the even needs to be represented by more than one pixel.
Pixel detection: so the running software needs to receive an input of video frames and compare pixels between frames. Ironically this is a common real-time process in video since compressed video is created with processors that (depending on compression scheme) look for similarities/differences between frames and for efficiency sake encode pixel changes and with math simplify any static parts (no need to be redundant).
what happens when the tracking isn't perfect and the Moon drifts a few pixels over a bit of frames. A false positive happens.
what happens with video noise as pixel values changes from frame to frame....A false positive happens...
There are a few packages that offer pre-roll (constantly recording to a buffer) and will capture the data to storage when triggered...
These apps are designed to detect meteors and other rare events:
Some of the top video editing software packages have auto-detect scene-change algorithms that (post record) analyze through clips and mark timecode. The value in the sophisticated ones is that the pixel change sensitivity can be customized. One can simply set the analyzer to take a few passes with different sensitivities and find candidates that can be manually watched.
As to recording and analyzing in post, it seems a better method as analysis can be performed at various levels to find a candidate that might have been a false-negative trigger with auto mode.
As to software resources nowadays, one can easily take advantage of macros and macro-recorders/task schedulers, etc. to set up their computer to analyze through recorded content without much effort.
Exposure-so unfortunately the events are rare so it would be futile to wait for events to use to calibrate your gear, but the challenge is capturing enough dynamic range in the darkened part of the Lunar surface so as to capture an event with a flash that is __ amount brighter. I imagine there would be a sweet-spot.
A trick I often use with auto-detect of events through a long video clip: post-process the footage in such a way that it makes the content easy for the detection analysis to work.
I can't explain at length since I rely on many years of video processing experience,
but realize that one is not limited by the constraints of the state of the raw video footage....
Add contrast, adjust the lift so regular noise is diminished, sharpen, etc......All easily done in a video editor and then can be rendered for analysis by the apps above, etc.....
As to "two witnesses" ie having two cameras/OTA to document that same event to rule-out a hardware issue (cosmic ray, random noise flash),
one may consider having two different quality set-ups. the redundant one only need to capture the event above the noise floor as a verification, and not need to be ultra-sensitive to trigger an auto-record trigger or be triggered with post analysis. Syncing time code (as simple as using a clapboard or audio time report) is all that is needed,
as once a likely candidate is found after manual viewing it (from software analysis results),
one can jump to the full recorded secondary setup and see if any noticeable event was captured.
Note there are some phenomenon that will produce some false positive flashes in two cameras: glint off a geostationary satellite transiting in front of the Moon (perspective-wise), also weather-balloon with flashing beacon, even a rare-head-on meteor (or smaller than resolution of capture gear) event entering our atmosphere), etc....
Having recording the Moon and Sun over many hours of time to capture other interesting things (like transits of balloons/birds/planes, etc), it isn't too much of a feat over the long run.
you just need to discipline yourself to regularly do it and don't expect first success...
As to frequency of occurrence, yes is important to realize that depending on set-up you might not capture often,
but having regularly filmed realtime video of telescopic meteors,
even with a narrow FOV, one can capture rare things some times.
It is often debated that one can capture more meteors with a wide lens, and yes for the bright and larger ones,
but I regularly experience capturing lots more total (including smaller/fainter) meteors with larger focal lengths with lenses that have large apertures and my sensitive a7s.
Not everything about capturing rare phenomenon and statistics is intuitive.....
As to the "leave it up to professionals," one need only look up the story of Lovejoy and his home set-up that has discovered a few comets.
One obvious flawed assumption ignores that often in astronomy funding for professional projects is hard to come by,
but any ol' amateur with some initiative can invest time and energy and resources that is probably lacking with pro efforts.
Best isn't best if it doesn't exist. And good enough is good enough to do it.....
Edited by t_image, 17 February 2019 - 04:50 PM.