originally posted by: ArbitrageurSaying it was observed in only one frame, and also saying it was static is a
contradiction.
The crater, assuming it is one, could be completely seen in only one frame. That's the frame I have provided in the OP. In this single frame, the
visibility of the whole crater was rather striking (pun not intended). In the frames after and prior to the one I provided, only parts of the crater
were visible. Those other frames made me confident about the fact the structure was static, but only parts of the structure were visible at a time.
Since then I have been monitoring the area more closely, using the same weather imagery. Same source I have provided earlier. I took the liberty of
saving screenshots of the views. When skies are clear, and the temperature is low enough for the artificial IR assigned colours to highlight ground
structures, some of the crater structure would become visible again.
The western part of the crater became visible again on the 28th Jan imagery data, after the picture I took on the 15th. I did something different from
the 15th though. This time, for that day, I took two subsequent pictures several hours apart. This is to allow you to evaluate the moving (clouds) and
the static (ground) structures, for yourselves. I shall post the pictures below, for your convenience:
Unlike the spectacular 15th Jan picture, the 28th Jan was not as cold, and less of the crater was highlighted in the imagery. Hopefully the 15th Jan
conditions will eventually repeat so we can get another clear and complete view of the thing.
So while I can see some ground features in the gray scales, I don't see them in the other colors in the temperature scale, which makes sense
since they are too cold to be ground surface temperatures.
You are correct. The colour is indicative of the temperature. The scale of the temperature is given in Celsius, and it approximate. The colour of an
object, in this imagery data, is independent of wether the observed object is a cloud, or the ground. Wether the object is a cloud or the ground can
be, as you correctly figured out, inferred from wether it is moving or static.
Cloud tops are usually extremely cold. Judging by the colour in the imagery, we are speaking of -30 C to -60 C range. This is purely approximate,
weather is not my area of expertise. Those temperatures are assigned artificial, vivid colours that help weather experts to differentiate clouds
(usually coloured) from the ground (usually warmer and so are usually gray).
In winter, though, it can get really cold up here in Quebec. And so, in this weather imagery source, the ground may take artificial colours such as
blue, especially in January and February, which is typically our very cold season. True enough, for the last week's we've been experiencing
temperatures around the -30 C during our nights.
This is why the crater suddenly became visible, in vivid artificial colours as opposed to shades of gray. With those vivid colours, the temperature
gradient between higher and lower grounds was highlighted, and the crater became much more visible.
When it gets warmer, the whole ground gets flooded with grays that are poorly differentiated, and ground structures are much less visible; this
highlights colourful (and much colder) clouds, which is of course the point of this artificial colours IR weather imagery.
I have been looking for a real-time, purely visible light imagery of the surface of the Earth, to bypass all that colour-code complication. We need
real-time imagery, as the Sun and its moving terminator line will highlight ground structures and be of tremendous help. However so far I have been
unsuccessful.
Also as others have already pointed out, the circular feature in your OP is not a match for the Mistassini-Otish Impact structure, though it's
in the same general vicinity. The size and location are not a match
You must keep in mind that Serge Genest never actually observed any craters associated with his theorized Mistassini-Otish impact event. All the
evidences he had presented came from ground analysis, not from visual satellite observations. So when he speaks of the size of the hypothetical
crater, he can only give a
very rough
approximation.
What we do "know" ("strongly suspect" would be the more adequate wording here, of course) is that the crater must at least reach the Mistassini Lake,
giving the lake its curved shape. Genest also had provided a rough estimate of the general epicenter of the impact.
The Swanne Crater shares a similar epicenter, of which the exact coordinates is a challenge to obtain given the absurdly large size of the structure,
parts of which are smoothened out. Also, the Swanne Crater does at least reach the Mistassini Lake. I initially measured it to be 370 km large, as
opposed to Genest's guesstimate of 500 km; however my own guesstimate was made in five minutes on Google maps. The most recent pictures I saved have
better resolution. I might therefore be able to compare the apparent crater with actual IR features on the ground, and get a better idea of its actual
size on a distance-measuring tool.
Given these considerations, there are two possible scenarios.
A) Either the Swanne Crater is the visible structure of the Mistassini-Otish impact event (provided both are confirmed, of course);
B) The Mistassini-Otish impact and the Swanne Crater are unrelated; they happen to have been caused by two different asteroids, both with the same
approximate record-breaking size, both striking at nearly the same spot, and both striking within a time frame prior to the Manicouagan Crater (which
is not deformed and therefore has occurred after).
While scenario B is not impossible, it would normally be considered extremely unlikely, at least much less likely than scenario A.