September 29, 2022

Wonder at the ‘false dawn’ of zodiacal light in early autumn

Wonder at the ‘false dawn’ of zodiacal light in early autumn
Wonder at the ‘false dawn’ of zodiacal light in early autumnWonder at the ‘false dawn’ of zodiacal light in early autumn

A band of eerie predawn light will put on a show for early risers over the next few weeks.

The phenomenon, known as zodiacal light, will be prominent along the eastern horizon before dawn between the autumnal equinox, which occurred on Thursday (Sept. 22), and the next full moon on Oct. 9.

Zodiacal light will be most visible in areas free from urban light pollution and will appear in the lower third of the sky next to the twin stars of Castor and Pollux in the constellation Gemini. If you’re in the Northern Hemisphere, look for zodiacal light during the early predawn hours from late August into early November. For the Southern Hemisphere, the phenomenon will be most visible in the evening hours around sunset, appearing in the west. 

Related: Night sky, September 2022: What you can see tonight [maps]

Zodiacal light, also known as “false dawn,” occurs when sunlight is scattered by interplanetary particles in the plane of the solar system, the same material that causes meteor showers. It will appear as a broad cone or wedge of faint light extending upwards from the eastern horizon into the ecliptic  — the path the sun appears to take in the sky. The zodiacal light will appear comparable in brightness to the Milky Way, and will even appear “milkier,” or lighter in appearance, according to EarthSky.org (opens in new tab)

Zodiacal light is most visible around the equinoxes because it follows the path of the sun through the sky. During the equinoxes, the sun is positioned directly above the equator. This means sunlight hits the horizon at its most extreme vertical angle during these times, brightly illuminating the interplanetary dust that creates the “false dawn” phenomenon.

A 360-degree panorama of the spring sky over the Badlands of Dinosaur Provincial Park, Alberta, on March 29, 2019, with the winter Milky Way and constellations setting at centre, and the spring constellations filling the sky at left and right. At centre is also the tapering pyramid-shaped glow of the Zodiacal Light, which continues to the left across the sky as the Zodiacal Band.

(Image credit: VW Pics/Getty Images)

If you want to take a photo of zodiacal light, try a long exposure to make sure your camera can capture the glow. For capturing the best pictures of the zodiacal light you can, check out our recommendations for the best cameras for astrophotography and best lenses for astrophotography

Editor’s Note: If you get a good photo of the zodiacal light and would like to share it with Space.com’s readers, send your photo(s), comments, and your name and location to spacephotos@space.com.  

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