Subj : Daily APOD Report To : All From : Alan Ianson Date : Mon Feb 01 2021 01:38:23 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. 2021 February 1 Lunar Halo over Snowy Trees Image Credit & Copyright: Göran Strand Explanation: Have you ever seen a halo around the Moon? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens. Because most of the crystals have a similar elongated hexagonal shape, light entering one crystal face and exiting through the opposing face refracts 22 degrees, which corresponds to the radius of the Moon Halo. A similar Sun Halo may be visible during the day. Exactly how ice-crystals form in clouds remains a topic of research. In the featured image taken last week from Östersund, Sweden, a complete lunar halo was captured over snowy trees and rabbit tracks. APOD is available via Instagram: in English, Indonesian, Persian, and Portuguese Tomorrow's picture: meteor streak and drift __________________________________________________________________ Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) NASA Official: Phillip Newman Specific rights apply. NASA Web Privacy Policy and Important Notices A service of: ASD at NASA / GSFC & Michigan Tech. U. --- SBBSecho 3.12-Linux * Origin: The Rusty MailBox - Penticton, BC Canada (1:153/757.2) .