Just two nights ago, my brother and I noticed a weird flashing light in the night sky out in the countryside. We regularly observe by naked eye aircraft flying by, as well as satellites, and this was not like anything we'd seen before.

It was only white light (no red, no green) , with the following sequence:

 *            _______          _______

Flash <-1sec-> strong light <-1sec-> dim light

The lines above the second and third lights attempt to show the fact that they faded gradually, while the first flash was like a camera flash, sudden and strong.

Every 3 seconds the cycle repeated. The source of the lights seemed to be the same, i.e the same strobe light. Besides, the aircraft was pretty far away or small: with binoculars, it wasn't possible to discern any other strobe lights or a structure of any kind.

We first noticed the light above Ursa Major, it moved towards Cassiopeia and gradually faded away either because it moved away from us or because of the strong moonlight of that night.

  • 3
    $\begingroup$ Related: Do lights on aircraft flash in a specific pattern? $\endgroup$
    – fooot
    Aug 11, 2017 at 1:29
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    $\begingroup$ Any kind of balloon or drone with a survival strobe attached to it could do this. $\endgroup$
    – Methark
    Aug 11, 2017 at 6:12
  • $\begingroup$ Thank you for your answers. No, @mins, it was around midnight, but again, this was periodic and it lasted for about 10 min. No satellite that I've seen produced anything like it. I was curious if maybe military aircrafts have different lights than civilian airplanes and this could be something like that. Or maybe it was indeed what methark suggested, a meteo balloon perhaps? Even though, if that is the case, I would expect to have noticed the light before, some night during all the years that we have been observing the night sky. $\endgroup$
    – Lefteris
    Aug 11, 2017 at 7:36
  • $\begingroup$ Hey. Well. All may apply. It's easier nowadays to spot non-registered scientific experiments with all open technology we have like italic_RapberryPi (even children can build something that goes high in the sky)_italic. But, no one can really answer for sure. :) About two years ago I saw a movie on YouTube of a 10 years old girl making a hydrogen powered balloon that took a homemade box with cameras, barometer and other stuff) went to the end of the stratosphere (the balloon pop out at the end) - all was recorded just in time. $\endgroup$
    – Methark
    Aug 11, 2017 at 12:09

1 Answer 1


Twenty cycles per minute means it wasn't an FAA-approved aircraft, so it probably wasn't manned, or even a weather balloon.

Satellites need no anticollision lights.

The bright strobe combined with the longer fading lights suggests something homebuilt. The light may have been adapted from consumer bicycle lights, which have quite a variety of patterns. Professional lights such as Whelen's models prefer flickering to fading, for both efficiency and visibility.


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