After sunset from February 10th to the 15th, you might be lucky enough to see a cone of light in the western sky. This eerie glow is called Zodiacal Light.
The shape resembles a tilted cone, wedge or slanted pyramid. From the base of the cone, the light may extend some 20 to 30 degrees along the horizon (a fist on your outstretched arm covers about 10 degrees of sky).
At its best, the display can equal the Milky Way in brightness. However, sometimes, it is so faint that a small amount of atmospheric haze can obscure it.
On exceptionally clear nights, the tapering cone might be seen to stretch more than halfway to the zenith, an imaginary point in the sky directly above you.
The Zodiacal Light is thought to be sunlight reflected from interplanetary dust grains lying mostly in the plane of the zodiac, or ecliptic. These dust grains are part of an enormous cloud of cosmic dust extending outward from the Sun and past the orbit of the Earth.
The reason for the name "zodiacal" light, is because the cone of light is usually seen projected against the zodiacal constellations – the pathway of the wandering planets.
This diffuse, night-sky luminosity can usually be seen on moonless nights at this time of year.
Katharine Auslander is a freelance journalist and a resident of Meaford who is very interested in astronomy and environmental issues. She has a Masters degree in Environmental Studies from York University.
