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above x2: Photos by David Finlay, from here.

The BBC news article Rare 'sprites' photographed beside Southern Lights shows photographs by the Australian photographer David Finlay. They are remarkably clear and distinct, and set against a clear night sky filled with stars. (The two fuzzy blue blobs are the large and small Magellanic Clouds - dwarf galaxies in the local group.)

I had thought that sprites were challenging to photograph not only because they are dim and rare requiring a special low-light cooled-CCD camera and luck, but that one had to be almost directly above a thunderstorm. This is a view of an almost completely clear sky, from the ground with a normal camera.

Are the clouds and light in the distance at the bottom of the first image the source of these sprites? There is really that much difference in altitude between the sprite and the associated thunderstorm?

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According to this Wikipedia entry Sprites occur at altitudes between 50 and 90km while the thunderstorms that create them generally top out below 16km so there is a minimum of more than 30km of height difference between a storm and any sprites it may spawn. So yes, at the right angle, you should be able to get a photograph of a storm's sprites from the ground. Whether the storm we can see in the photo is in fact the source of those sprites I don't know, given the angles I think the part of the storm that created them is actually below the horizon.

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  • $\begingroup$ Oh! I see, so one can be several hundred kilometers away in dark clear skies and look in the direction of a thunderstorm well over the horizon and invisible and yet have a good clear shot at any sprite activity associated with it; all you'd need is a good up-to-date weather map that included lightning strike frequency? Cool! $\endgroup$
    – uhoh
    Nov 18 at 3:35
  • $\begingroup$ "All you'd need"... well, you make it sound a little easier than it is. Honestly, of all the weather photographers\storm chasers I know with such passion for all things weather (quite a few people drove doubledigit hours each way last week hoping to see an aurora in the Northern Plains for example), I'm not sure I know a single one that has managed to get\see a sprite. They're in the ultra rare category, at least to be visible to the eyes\camera, unless I've misunderstood. $\endgroup$ Nov 18 at 12:56
  • $\begingroup$ And rare to the point that I'm not sure most atmospheric scientists can even give much input on whether such a photo as this one is legitimate. As Ash mentioned, some of the numbers line up... but beyond that, not sure many people exist that can give a real idea of whether it matches experientially. In terms of being able to judge pictures, it's not all that different in trying to judge as less-concretely-verified phenomena like the green flash or ball lightning or such. Seems just tough to pin down whether any particular picture is truly real or some kind of artifact... $\endgroup$ Nov 18 at 13:02
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    $\begingroup$ I'm wondering about exposure time though, In my latter source they say that sprites last up to "many tens of milliseconds". Let's say 0.1s. I'm not into photography, but is an exposure time of 0.1 seconds "a large amount of time" for this kind of low light photography? And even if it is not, it must have been insane luck to capture this. Regarding "How is this possible" - I'm rather wondering about the chances of capturing this than the clear sky. Sorry for making this chatty. I'd also very much like to see a profound answer to this. $\endgroup$
    – J. Fregin
    Nov 18 at 15:28
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    $\begingroup$ @J.Fregin that's a great question, so much so that I recommend you post it as a new question. You could do it here but the folks in Photography SE and add the Astrophotography tag may find it interesting and dig in as well. $\endgroup$
    – uhoh
    Nov 27 at 11:39

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