May 2, 2018
Light takes eight minutes to travel from the Sun to the Earth. It took the universe 13.8 billion years to make you.
Moon Halo over Stone Circle
Birthday · May 2, 2018
A little universe, just for you
Your date.
Ready to give.
Free PNG · 1080 × 1350 · No account needed
Image rights and credit requirements apply when sharing or reusing imagery.
Date & occasion only
Change the year
APOD published May 2, 2018. Credit: Alyn Wallace Photography. A publication-date match, not a photo taken on your date. Independent of NASA.
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 under investigation. In the featured image, the ice circle in the sky is mirrored by a stone circle on the ground. Taken just over a month ago in Pontypridd Common, Wales, UK, the central Rocking Stone survives from the last ice age, while the surrounding stones in the circles were placed much more recently -- during the 1800s. Follow APOD on: Facebook, Google Plus, Instagram, or Twitter
Image credit: Alyn Wallace Photography