What is Zodiacal Light?

Zodiacal light is a faint, glowing band of light that stretches across the night sky. It looks like a soft triangle of light rising up from the horizon. This glow appears along the path the Sun travels through the sky, called the ecliptic.

The light doesn’t come from stars. Instead, it comes from sunlight reflecting off tiny dust particles floating in space throughout our solar system. These particles are about the size of cigarette smoke and come from things like comets shedding material and collisions between asteroids.

Because this dust lies in the same flat plane as the planets, the glow follows the zodiac constellations. That’s why it’s called zodiacal light.

Sometimes people call it the “false dawn” or “false dusk” because it can look a bit like early morning or evening twilight.

To see it, you need very dark skies, no moonlight, and a clear view of the horizon.

When Does Zodiacal Light Occur?

Zodiacal light can appear at different times of the year, but it is easiest to see around the spring and fall equinoxes. For Denver skywatchers, the weeks around the spring equinox (March 20, 2026) are one of the best times of the year to spot zodiacal light. Around the equinoxes, the ecliptic tilts steeply upward from the horizon, which makes the glowing dust cloud stand out more clearly against the dark sky.

Look toward the western horizon after sunset on clear evenings in March and early April once twilight has fully faded.. You may see a faint, triangular glow rising upward along the ecliptic — path where the planets travel. The glow should appear smooth and diffuse, unlike the Milky Way which has a clumpy or mottled look from all the stars inside it.

Best Viewing Tips

To improve your chances:

• Wait until at least 90 minutes after sunset

• Make sure the Moon is not bright in the evening sky

• Let your eyes adjust to the dark for about 20 minutes

• Look for a soft pyramid-shaped glow rising from the western horizon

The best places to see it around Denver are dark sky sites away from city lights, like the Kline-Dodge Dark Sky Site. For a list of other dark sky sites, check out our post on Where to Explore the 2026 Denver Night Skies. These places provide the clear, dark skies perfect for spotting zodiacal light. Even experienced observers sometimes miss it, so patience helps!

A Hidden Extension — The Gegenschein

Advanced observers sometimes notice another faint glow called the Gegenschein, which appears on the opposite side of the sky from the Sun. It’s caused by the same cloud of interplanetary dust but is much dimmer and harder to detect.

While the zodiacal light is visible to the naked eye under dark skies, the Gegenschein usually requires very dark conditions and careful observation.

Keep Looking Up

Zodiacal light is one of the most subtle sights in the night sky, but once you see it, you’ll never forget it. It’s a reminder that our solar system isn’t empty—it’s filled with tiny particles left behind by comets, asteroids, and the processes that built the planets.

If you’re heading out to dark skies this spring, take a few minutes after twilight fades to look toward the western horizon. You might just catch the quiet glow of sunlight reflecting off the dust of our solar system.

Clear skies and happy light-gazing.