2004 August 25
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 in the left frame taken in
Namibia in May.
Rolling the
cursor
over the image will bring up labels.
Bright
zodiacal light can be seen nearly every clear moonless
morning over the next few months on images taken by the
Mauna Kea,
Hawaii fisheye
CONCAM 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.