Астронет: Астрономическая картинка дня Четырехкратное лунное гало над зимней дорогой http://variable-stars.ru/db/msg/1798582/eng |
Credit & Copyright: Dani Caxete
Explanation:
Sometimes falling ice crystals make the atmosphere into a
giant lens causing arcs and halos to appear around the Sun or Moon.
One Saturday night in 2012 was just such a time near
Madrid,
Spain,
where a winter sky displayed not only a bright
Moon but four rare lunar halos.
The brightest object, near the top of the featured image, is the Moon.
Light from the Moon
refracts
through tumbling hexagonal ice crystals into a somewhat rare
22-degree halo
seen surrounding the Moon.
Elongating the 22-degree arc horizontally is a more rare
circumscribed halo caused by
column ice crystals.
Even more rare, some moonlight refracts through more distant
tumbling ice crystals to form a (third)
rainbow-like arc 46 degrees from the Moon and appearing here
just above a picturesque winter landscape.
Furthermore, part of a whole
46-degree circular halo
is also visible, so that an extremely rare -- especially for the Moon --
quadruple halo
was captured.
Far in the background is a famous winter skyscape that includes
Sirius, the
belt of Orion, and
Betelgeuse -- visible between the inner and outer arcs.
Halos and arcs typically last for minutes to hours,
so if you do see one there should be time to invite family,
friends or neighbors to
share your
unusual lensed vista of the sky.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.