In the early hours of the morning of 8th September 2019 at 04:51:33 UTC a meteor streaked through the skies of southern England causing observers to wonder what was afoot. Indeed, following numerous reports to the local police, Plymouth police and coastguard helicopters were scrambled to go to the aid of … of what exactly ?
Well, a few hours later, as I was processing the overnight clips from the three meteor cameras here at Clanfield Observatory, I came across an unusual image which at first sight was just one of the many aircraft that criss cross the skies above the South Downs. It was across the entire field of view of the camera, dipping and slightly brightening as it left the lower right hand (south westerly) quadrant of the camera’s field of view. What made it unusual was the fact that there was no periodic brightening which typifies most aircraft tracks on an integrated jpg still.
Nothing for it, I’d just have to download the video to check it out .. darn. Whatever it was, the avi file is over 200MB so this was going to take a while! Eventually, and after a couple of runs of the video, I was convinced it was a meteor trail, with a shortish persistent trail for most of the time it was in frame. Processing it in UFO Analyser was a challenge. Since it was already twilight, there were virtually no stars visible and this made it impossible to link the reference star map to the scintillation frame. So I downloaded a second “normal” meteor from earlier in the night and was able to link to that and then process both meteor clips successfully.
According to UFO Analyser, it was a magnitude -3.7 Sporadic with a duration of 8.2 seconds. That duration was clearly a minimum as the meteor was faintly visible entering the field of view and it clearly still had business to attend to as it left the frame towards the south west.
So I decided to post it on the UKMON Dashboard and it was when I went to do this that I spotted the first alert from Richard Kacerek reporting the public observations and the following wide angle sky image from Richard Bassom.
Some time later, Richard Fleet posted the corresponding images from two of his cameras, together with their csv files. This meant I could combine the csv files for Wilcot and Clanfield in UFO Orbit to get the following visualisation of the ground path:
Around the same time Jim Rowe was posting similar results from the SCAMP/FRIPON stations confirming our results, but wi th a rather prettier graphic:
Clearly, those members of the public who swore blind that this meteor had landed close to where they were standing, were mistaken! A common misconception brought about by a total absence of scale. In fact the meteor was more than 60 kilometers above the ground and much further south! Interestingly, looking at the Unified Wilcot and Clanfield data, H1 was 58km. (pretty low) and H2 was 65km., not what I was expecting, at all ! And the ground trail is over the coast of northern France - quite some journey for those poor helicopter pilots !
But it was most unusual. Instead of the typical flight time of around a half of a second, Richards Bassom and Fleet confirmed that this guy hung around for more like 25 seconds, travelling at a very slow 10 kms per second. So was it even a meteor ? That velocity is below the normal minimum seen in the text books. Could it have been a piece of space junk ? I don’t know. If it was a meteor then it was very similar to other “earth grazers that we have seen previously”.
There were reports that it broke up (into two?) which might suggest that something did come to earth, albeit in the Atlantic Ocean.
Whatever the final outcome of the ongoing analysis, this event proves the need to look up and to engage with the public to explain these events when they occur. Otherwise they will continue to fear the worst!
Steve Bosley: Clanfield Observatory