Short Version: went camping into a very dark, remote location with clear air, no moon. Was able to see everything from the Pleiades and Orion, to the Southern Cross and the Magellanic Clouds (I live in Chile).

Within the Milky Way arm belt, we saw a noticeable flash; very quick; very short. Nothing crazy bright, but enough to catch our eyes while laying down looking up star gazing.

I want to say it was a distant supernova, but everything I read says "no they are too rare, etc."

We have seen maybe 5-6 in the last few years. Saw a couple up in the Atacama Desert as well...

Are these indeed supernovas or something else? While looking up it just looks like a really bright star or Jupiter/Venus, then in a nanosecond it's gone.

Please help!

  • $\begingroup$ You may have seen a satellite move by, see astronomy.stackexchange.com/q/11634/31410 $\endgroup$
    – WarpPrime
    Commented Jan 31, 2022 at 18:20
  • 5
    $\begingroup$ Supernovae visibly explode over a much longer time period than a few seconds. $\endgroup$
    – user438383
    Commented Jan 31, 2022 at 18:22
  • 1
    $\begingroup$ Some additional info could help, if you have any. Where in the sky was it? What constellation? How close to the horizon? What time of night? How long was the flash? Did it move? How many times did it flash? How bright did it appear (compared to other bright stars)? $\endgroup$
    – zephyr
    Commented Jan 31, 2022 at 19:21
  • 2
    $\begingroup$ How many meteors did you see during the time you were looking at the sky? $\endgroup$
    – James K
    Commented Jan 31, 2022 at 22:56

1 Answer 1


Interesting! Could you provide a few more details: what date/time? roughly where in the sky (nearest constellation, as well as how near to the horizon/which cardinal direction would be helpful)? It would also be helpful to know roughly how high above sea level you were during this sighting.

The other answers are right in that supernovae are unlikely to appear so brief, you can see here what a supernova explosion's "light-curve" (a plot showing an object's brightness over time) typically looks like. They tend to stay quite bright for ~days/weeks rather than seconds. Some alternative hypothesis would include:

  1. a faint meteor could appear as a flash rather than a streak.
  2. satellites sometimes rotate in such a way that they briefly reflect sunlight directly towards an observer, making it suddenly brighten. This would be most likely if the observation was near the horizon or near to dusk/twilight
  3. high energy particles can sometimes strike the human retina, which the brain interprets as a flash of light. This is known to occur mostly during space flight (Cosmic ray visual phenomena). I don't know of any ground based studies of this phenomenon, since our atmosphere typically blocks such high energy radiation, however it is theoretically possible, particularly at high altitudes.

I hope this helps! Depending on the questions above I may be able to narrow down the likely causes further. This is certainly an interesting observation!


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