Zodiacal Light

space · astronomy · night sky

Cosmic dust scatter. The zodiacal light happens when sunlight bounces off tiny dust particles that orbit between the planets in our solar system. There are so many of these particles floating around that together they create a visible glow.

Best time to see it. You can only spot the zodiacal light in a really dark place away from city lights, on a clear night when the Moon isn't bright. It looks like a faint triangle of light rising from the Sun's direction along the path of the zodiac.

Spans whole sky. The zodiacal light actually covers the entire sky with a faint glow, but it's brightest near the Sun and dimmer everywhere else. This gentle light adds to the natural brightness of dark night skies when the Moon isn't shining.

The opposite glow. A related phenomenon called the gegenschein is sunlight bouncing back from dust on the opposite side of the Sun from where you're standing. It appears as a slightly brighter oval patch directly opposite the Sun in the night sky.