Zodiacal Light and the False Dawn
Explanation:
An unusual triangle of light will be particularly
bright near the eastern horizon before sunrise
during the next two months for observers in Earth's northern
hemisphere.
Once considered a false dawn, this triangle of light is actually
Zodiacal Light, light reflected from
interplanetary dust particles.
The triangle is clearly visible on the left of the
above frame taken from
Mauna Kea in
Hawaii on September 8 by one of the developing
global network of fisheye nighttime web cameras,
called
CONCAMs, of the
Night Sky Live Project.
Zodiacal dust
orbits the
Sun
predominantly in the same plane as the planets: the
ecliptic.
Zodiacal light is so bright this time of year because the
dust band is oriented
nearly vertical at sunrise,
so that the thick air near the horizon does not
block
out relatively bright
reflecting dust.
Zodiacal light is also bright for
people in Earth's northern hemisphere
in March and April just after sunset.
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.
