Астронет: Астрономическая картинка дня Новогодние северные сияния http://variable-stars.ru/db/msg/1949059/eng |
Credit & Copyright: Alessandra Masi
Explanation:
It was a new year, and the sky was doubly red.
The new year meant that the
Earth
had returned to its usual place in its orbit on January 1,
a place a few days before its
closest approach to the
Sun.
The first of the two red skyglows, on the left, was a red
aurora,
complete with vertical rays, caused by a
blast from the Sun
pushing charged particles into
Earth's atmosphere.
The second red glow, most prominent on the far right,
was possibly a
SAR
arc caused by a river of charged
particles flowing across
Earth's
atmosphere.
Although both appear red, the
slight color difference is likely due to the aurora being emitted by both oxygen
and nitrogen, whereas the higher
SAR arc was possibly emitted
more purely by atmospheric oxygen.
The
featured image was taken on January 1 from near
Pieve di Cadore in
Italy.
Portal Universe:
Random APOD Generator
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.