I read with interest this report of a superheated ribbon of gas photographed in the upper atmosphere.
What is the SD on this phenomenon? What is the gas and what process creates this?
I don’t know, but I was even more surprised to read that these ribbons of superheated gas, so dramatically visible in the photograph, are “very common,” but “we’ve never noticed them before.”
Maybe they’ve only recently become “very common”.
Dramatically visible in a long exposure photo. It wouldn’t look like that to the naked eye and would most likely be considered part of the aurora.
An interesting article about the difference between what the eye sees and what the camera can pick up when used correctly. Note the comparison about halfway down the page. These Steves probably don’t look like much.
A camera will pick up more of an aurora than the naked eye will. But the biggest difference between the pictures and what you’re likely to actually see is that the pictures all come from the absolute most spectacular auroras, and the one you see probably won’t be that spectacular. If, however, you’re lucky enough to actually see one of those really good ones in person, it really will look almost as good as the pictures.
I don’t know anything about Steves, though. I’ve never seen a Steve (at least, not to my knowledge).
Is that really a long exposure photo? The article doesn’t say (as far as I can see), but aurora typically move around pretty fast, so I would think a long exposure would show blurring. The stars are pointlike, so it couldn’t be a very long exposure unless the camera is on a clock drive, in which case I would expect the Steve to be blurred.
Here’s the original photo on Facebook. The exposure and lens information was a focal length of 11.5mm, f-stop of 2.8, and an exposure time of 30 seconds on ISO 2000 film. (Or the digital equivalent, I guess.)
I’m not a photography expert, but IIRC, ISO 2000 indicates a fairly high degree of light sensitivity. A 30-second exposure with this degree of light sensitivity is long enough to show things your eye would be unable to pick up; but it’s not long enough to cause significant star trails (the earth rotates 1/8° in that amount of time.)
That said, the photographer also implies on his sale page that the display was visible by eye. So who knows?
Well, sure it was visible to the naked eye. But it didn’t look the same.
Whoa, there are people still using film?
(Visualizes something like the Earthrise photo, with wisps of smoke or steam rising from the planet…)
Thanks all. Wikipedia doesn’t provide anything more than the BBC article and nor does this article but at least it shows a video that might give a better idea about Steve’s brightness. Introducing Steve - a Newly Discovered Astronomical Phenomenon : ScienceAlert
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Can these figures be correct? They seem awfully high.
Maybe they’ve mistaken a degree mark Perhaps the temperature is for a zero?
Maybe the comma is actually a decimal point, not a thousands separator? This is the convention in Canadian French.
Perhaps the temperature is 3.00°C warmer, instead of 3000C.
The shuttle heated up to 3,000 F during re-entry.
I don’t doubt the numbers. Just because a parcel of gas is at a high temperature, doesn’t mean it contains a lot of heat. It’s probably very diffuse, to the point that the heat is almost negligible. For comparison, the corona of the Sun is millions of degrees, but if you were stranded in the corona and somehow shielded from the direct light of the photosphere, you’d freeze to death.
I suspect that this was just the digital equivalent of ISO, which is apparently a thing. See here, for example.
The Nikon D300 cited in the linked post is a digital camera so the 2000 ISO is digital equivalent. My Canon 7D (digital) has ISO settings from 100 to 64000 (yes, that’s three zeroes). When I shot film the highest ISO film commonly available at the consumer level was 1600, so 2000 is pretty high.
For a camera to calculate exposure using the traditional f-stop and shutter speed settings, it must also consider a sensitivity setting for which the ISO number continues to be used. If you halve the f-stop number or double either of the other two, then you are increasing the exposure by one stop.