Re: Laser beam obs

Bart De Pontieu (BDP@MPE.MPE-GARCHING.MPG.DE)
Mon, 27 Feb 1995 15:06:07 +0100 (CET)

Jonathan McDowell wrote in seesat/173 :

>They definitely don't have laser detectors or reflectors. So
>if someone was firing a laser at them, it must just have been
>to test a ranging device powerful enough that it doesn't require any 
>cooperation
>from the object. But on the whole I am inclined to the view
>expressed by Mike:
>> Maybe the moral to this story is that if someone says I saw something
>> in about that direction at about that time, there will always be at
>> least one of the 4000 pieces of debris in approximately the right
>> direction at the approximate time of observation.  Call me skeptical.

Though I agree with this conclusion, the fact remains that a laser beam
was seen moving quickly across the sky, with a brightening at the end of
it. The circumstances (position/time) may not have been reported with
sufficient accuracy, but the observation *was* made. Three possibilities
are left, I think :

1. The date/time/position were completely wrong. I think this is doubtful,
since the observer is an experienced amateur astronomer.

2. It was a ground-based laser, and it was directed at a satellite of which
the orbital elements are not in any of the publicly available files.

3. It was a ground-based laser and the brightening at the end was not a
satellite, but an 'artificial star' as they are formed in active optics
experiments.

It seems very unlikely we will ever find out what it was, unfortunately.
Thanks to all the people contributing to this thread!

Cheers,
   Bart