View larger. | Eastern sky, about an hour after sunset, on October 29, 2017. Photo taken by Asthadi Setyawan at Selorejo River Dam, Malang, East Java, Indonesia.
It’s true that mountains sometimes cast shadows on clouds. See a mountain shadow and find an explanation from sky optics expert Les Cowley at his wonderful website Atmospheric Optics. But this photo – submitted to EarthSky by a photographer we’ve known for years, Asthadi Setyawan in East Java, Indonesia – is mysterious. We ran it past Les Cowley for an explanation, who wrote:
I’m unsure about this. I’ve had it in PhotoShop, and both the image and EXIF data ring genuine.
However, the lens setting was reasonably wide angle and a shadow so high from a westerly object cast onto clouds in the *eastern* sky is impossible 30 minutes after sunset. If the camera clock was accurate (?) then it was indeed 37 minutes after a tropical sunset, and the sky would be quite dark. Under those conditions the sun could not cast shadows even on stratospheric clouds.
??
In fact, Asthadi later commented, he has six different shots of this scene, all in the same direction and all with a shadow. He also confirmed:
…the sky was quite dark at that time.
There was a moon up that night, but it would have been high in the south-southeast at the time of the photo and so can’t be the shadow’s source. We also considered the town lights, but Les said that – given the fact that Asthadi was using a wide angle lens, placing the shadow edge fairly high in the sky – he couldn’t see see how surface lights could be the source. As Les commented:
A mystery!
A mystery to us, anyway. Maybe some of you have ideas. Beautiful photo, no matter what the explanation. Thank you, Asthadi and Les!
Bottom line: This photo looks like a mountain shadow on clouds, but we haven’t figured out the shadow’s source.
from EarthSky http://ift.tt/2lZBhjE
View larger. | Eastern sky, about an hour after sunset, on October 29, 2017. Photo taken by Asthadi Setyawan at Selorejo River Dam, Malang, East Java, Indonesia.
It’s true that mountains sometimes cast shadows on clouds. See a mountain shadow and find an explanation from sky optics expert Les Cowley at his wonderful website Atmospheric Optics. But this photo – submitted to EarthSky by a photographer we’ve known for years, Asthadi Setyawan in East Java, Indonesia – is mysterious. We ran it past Les Cowley for an explanation, who wrote:
I’m unsure about this. I’ve had it in PhotoShop, and both the image and EXIF data ring genuine.
However, the lens setting was reasonably wide angle and a shadow so high from a westerly object cast onto clouds in the *eastern* sky is impossible 30 minutes after sunset. If the camera clock was accurate (?) then it was indeed 37 minutes after a tropical sunset, and the sky would be quite dark. Under those conditions the sun could not cast shadows even on stratospheric clouds.
??
In fact, Asthadi later commented, he has six different shots of this scene, all in the same direction and all with a shadow. He also confirmed:
…the sky was quite dark at that time.
There was a moon up that night, but it would have been high in the south-southeast at the time of the photo and so can’t be the shadow’s source. We also considered the town lights, but Les said that – given the fact that Asthadi was using a wide angle lens, placing the shadow edge fairly high in the sky – he couldn’t see see how surface lights could be the source. As Les commented:
A mystery!
A mystery to us, anyway. Maybe some of you have ideas. Beautiful photo, no matter what the explanation. Thank you, Asthadi and Les!
Bottom line: This photo looks like a mountain shadow on clouds, but we haven’t figured out the shadow’s source.
from EarthSky http://ift.tt/2lZBhjE
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