Астронет: Астрономическая картинка дня Схождение противосумеречных лучей http://variable-stars.ru/db/msg/1477463/eng |
Credit & Copyright: Juraj Patekar
Explanation:
Is there ever anything interesting to see in the direction opposite the
Sun?
Sometimes there is.
Notable items include
your own shadow,
a shadow of the Moon during a total solar eclipse,
a full moon --
in eclipse if the alignment's good enough,
a full earth,
planets
at
opposition,
glints from
planets,
the gegenschein from interplanetary dust,
the center of a rainbow,
hall-of-mountain fogbows,
an airplane glory,
and something
yet again different if your timing, clouds and Sun position are
just right.
This different effect starts with clouds near the
Sun
that are causing common
crepuscular rays to stream though.
In the featured rare image taken from an airplane in mid-April,
these beams were caught converging
180 degrees around,
on the opposite side of the sky from the Sun, where they are called
anticrepuscular rays.
Therefore, it may look like
something
bright is shining at the
antisolar point
near the image center, but actually it is
reverse-shining because, from your direction, light is streaming in, not out.
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.