Astronomy Picture of the Day

Explanation: What's that strange light down the road? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System appears prominently just after sunset -- or just before sunrise -- and is called zodiacal light. Although the origin of this dust is still being researched, a leading hypothesis holds that zodiacal dust originates mostly from faint Jupiter-family comets and slowly spirals into the Sun. Recent analysis of dust emitted by Comet 67P, visited by ESA's robotic Rosetta spacecraft, bolster this hypothesis. Pictured when climbing a road up to Teide National Park in the Canary Islands of Spain, a bright triangle of zodiacal light appeared in the distance soon after sunset. Captured on June 21, the scene includes bright Regulus, alpha star of Leo, standing above centre toward the left. The Beehive Star Cluster (M44) can be spotted below centre, closer to the horizon and also immersed in the zodiacal glow.