Cosmic dust in the plane of Earth's orbit around the Sun
Cosmic dust in the plane of Earth's orbit around the Sun
The image shows the so-called zodiacal light – interplanetary dust lit up by the Sun's radiation. The name comes from the Latin name for the circle of animals – the Zodiac – that describes a 20 degree-wide zone in which the 12 constellations can be seen during the course of the year. It can only be seen as a triangular glow in a dark night sky with no light pollution or interfering moonlight. This photo was acquired in September 2009 at the European Southern Observatory's (ESO) La Silla Observatory in Chile, looking west just a few minutes after sunset. A sea of cloud covers the valley below La Silla, which is at an altitude of 2400 metres. The Cassini probe first investigated this type of planetary dust with the Cosmic Dust Analyzer (CDA) in 1997 to 2004 en route to Saturn, and then over 13 years in the Saturnian system.
