Rare Devil Sunrise appears in multiple countries across earth

[u/Dexter_Naman]

[u/NuclearThane]

Surprised I had to go this far down to find someone asking. Yeah you nailed it that's exactly what causes it. Unclear whether the same phenomenon can happen with a sunset, but my assumption is that it would be the reverse effect-- i.e. the sun would start to look more like an arch with the points touching the horizon.

[u/jacob_ewing → u/NuclearThane]

I (not an expert in any related field) imagine it could go either way as the moon's position isn't tied to the sun's.

[u/IsraelZulu → u/jacob_ewing]

But the moon is always traveling in the same direction, and the earth always rotates in one direction. So, certain alignments and relative movements will be impossible.

[u/KuduBuck → u/IsraelZulu]

Yeah but the moon starts traveling in front of the sun and then passes the sun so depending on the timing it could be an upside down devil horns or a right side up

[u/IsraelZulu → u/KuduBuck]

Whether it's horns or an arch depends on timing. However, due to the consistency of the relative motions in play, horns on a sunrise will always get thicker as the moon moves past the sun. On the other side then, during sunset, an arch would similarly be getting thicker while the sun goes down and the moon moves past it.

What you can't have, for one example, is horns that get thinner during sunrise.

[u/IsraelZulu → u/[deleted]]

ORLY? Video here makes it look the other way around.

[u/pattyofurniture400 → u/IsraelZulu]

I think it looks thicker as it rises because the sun is getting brighter and therefore more overexposed. During an eclipse, the moon takes about 5 hours to traverse the full diameter of the sun. During a sunrise, the sun takes about 5 minutes to go from partially visible to fully above the horizon. So any actual change in thickness is negligible.