This object was observed from inside the car whilst driving southwest on the A505 just outside Royston England. It was noticeably green in colour (like a ‘washed out’ green traffic light). Both the colour and the brightness seemed constant for the few seconds we were observing before it fell below the low local horizon. Given the limited view through the windscreen of a moving car I believe the object may have marked a long path across the sky, but that we saw only a fraction of the apparition. I did not remember to see if it left a trail – but that would have probably been too difficult to discern from inside the car anyway. Magnitude is very difficult to estimate – my best guess is about minus 10 – comparable to the integrated light of the first-quarter moon! Similarly the size is difficult to estimate, due to the glaring brightness, but the ball of light was about 10 to 20 arc minutes (slightly smaller than the moon).
I have noted down a few of the details which might possibly assist in linking this observation with any meteor-cam data others may have collected. I would be interested to learn if others had reported this object. My guess is that it was a part of space debris as the colour was very notable, pure and constant.
The following data was taken from measurements made the following morning from inside the car with an inclinometer and from Google Earth Street View ‘bearings’ from the known location.
Date/ time: 1st June at between 22:38.3 hours UT to 22:39.3 hours UT (times subsequently corrected from car clock to GPS clock to obviate error of car clock)
Location: 52deg 2 min 36 sec N, 0 deg. 4 min 16 sec West
Azimuth at start of observation approx. 188 degrees (from Google Earth)
azimuth at end of track (local horizon) 213 degrees.
Altitude approx. 28 degrees at start and 8 degrees (local horizon) at end.
Duration: 2 to 3 seconds (estm.)