What is this Dark Mysterious Line in the Sky

Magic77

New Member
A few months ago, I was recording this unusual event in the sky. I've never seen anything like it before. There were planes and jets flying above the cloud layer. It was that strange cloud layer that seems to accumulate like a canopy over the sky. It actually makes the clouds really shiny and bright. There was this line that seemed to trail across the sky. In the past, you would never see a shadow on the clouds above you. I though maybe it was a laser or something. In order to create such a distinct shadow in the sky, on the clouds, wouldn't there need to be a large amount of metals above us?

 

deirdre

Senior Member.
if you give the guys a location and date/timestamp they can probably tell you what plane exactly left that contrail. although looks super windy that day.
 

Trailblazer

Moderator
Staff member
A few months ago, I was recording this unusual event in the sky. I've never seen anything like it before. There were planes and jets flying above the cloud layer. It was that strange cloud layer that seems to accumulate like a canopy over the sky. It actually makes the clouds really shiny and bright. There was this line that seemed to trail across the sky. In the past, you would never see a shadow on the clouds above you. I though maybe it was a laser or something. In order to create such a distinct shadow in the sky, on the clouds, wouldn't there need to be a large amount of metals above us?


As others have said, it is a shadow of a contrail. The contrail itself is visible between the sun and the shadow, through the cloud layer.

You_Doodle_2017-01-04T01_18_03Z.jpg

I'm not sure why you think "metals" would be involved. A trail of metal dense enough to block out the sun seems rather unlikely, but clouds (which is what contrails are) can do that easily.

The cloud sheet looks like cirrocumulus, which is a high-level cloud (20,000-40,000 feet). Contrails are usually found between about 28,000 and 40,000 feet, but in this case the trail is clearly above the cloud deck. In fact in this case the narrow and sharply defined shadow suggests that the contrail is actually rather close to the cloud layer. Often contrail shadows are less sharp, suggesting a greater distance between the trail and the cloud: you can often see them on lower altostratus or altocumulus cloud decks.

During the course of the video, the contrail drifts from right to left with the wind, crossing the sun from your perspective, so by the end of the video the shadow is on the opposite side (left) of the contrail from where it started.

As suggested above, if you tell us where and when you saw it, we can probably identify the plane.
 
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Trailspotter

Senior Member.
In order to create such a distinct shadow in the sky, on the clouds, wouldn't there need to be a large amount of metals above us?
Any sufficiently opaque object would cast a distinct shadow, and contrails can be quite dense optically to do it.
Here, for example, the satellite image of southeast of the UK taken by the Terra satellite on December 2, 2016 and available from the EOSDIS Worldview:
image-download.jpeg
There are several contrails casting shadows on the cloud layer underneath and standing out on its background.
 
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