|
REPLY TO THREAD
|
|
Subject
|
Look! Up in the sky! A Rare Photo of an Amazing Ice Halo Display!!
|
|
User Name
|
|
|
|
|
|
|
| Font color:
Font:
|
|
|
|
|
|
Original Message
|
Mind you, this picture is real.
[link to farm9.staticflickr.com]
David Hathaway – appropriately enough, a solar physicist at NASA’s Marshall Space Flight Center in Huntsville, Alabama – took it using a wide-angle lens to get the whole thing. It’s a High Dynamic Range shot, meaning he combined pictures with 3 different exposure times to see both faint and bright things simultaneously. He took the shot on October 30, 2012.
Everything you’re seeing here is pretty well understood: they all have a name and a specific set of circumstances under which you can see them.
The Sun is the bright blob near the horizon. It’s circled by the 22° halo, a fairly common optical effect in the winter; I see dozens every season. On either side of the Sun are parhelia, nicknamed sundogs. Those are the teardrop-shaped rainbows. Sometimes, as seen here, these stretch out into long streamers called parhelic circles. They are parallel to the horizon but in this wide-angle shot the shape is distorted, bending them up.
Directly above the Sun, dipping down to touch the halo (the math term for this is osculating, which means kissing) is a gull-wing curve called the tangent arc. Above it, connecting the "wings", is the Parry arc.
Above the tangent and Parry arcs is a faint rainbow (well, it’s not caused by raindrops, but it’s broken up into colors and has the familiar rainbow-shape) called the Parry supralateral.
There are two more to go and you can read the rest here:
[link to blogs.discovermagazine.com]
|
|
Pictures (click to insert)
|
 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | | | Next Page >> |
|
