APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Moon Corona, Halo, and Arcs over Manitoba
Explanation: Yes, but could you get to work on time if the Moon looked like this? As the photographer was preparing to drive to work, refraction , reflection , and even diffraction of moonlight from millions of falling ice crystals turned the familiar icon of our Moon into a menagerie of other-worldly halos and arcs . The featured scene was captured with three combined exposures two weeks ago on a cold winter morning in Manitoba , Canada . The colorful rings are a corona caused by quantum diffraction by small drops of water or ice near the direction of the Moon . Outside of that, a 22-degree halo was created by moonlight refracting through six-sided cylindrical ice crystals . To the sides are moon dogs , caused by light refracting through thin, flat, six-sided ice platelets as they flittered toward the ground. Visible at the top and bottom of the 22-degree halo are upper and lower tangent arcs , created by moonlight refracting through nearly horizontal hexagon al ice cylinders. A few minutes later, from a field just off the road to work, the halo and arcs had disappeared, the sky had returned to normal -- with the exception of a single faint moon dog .
| Date | February 24, 2020 |
|---|---|
| Credit | Image Credit & Copyright: Brent Mckean |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



