A strange triangle will appear in the zodiac this month. How to see rare 'zodiacal light,' before it disappears.

The image captures a zodiacal light, a triangular glow seen in the night sky.

The zodiacal light from the European Southern Observatory's La Silla Observatory in Chile in September 2009. (Image credit: ESO/Y. Beletsky)

A strange triangle of light will glow in the sky during late twilight in the southwest this month —, but it will only be visible in inky black, moonless skies, and only during the second half of February.

Zodiacal light, often called "false dusk," is a phenomenon caused by sunlight scattering off interplanetary dust particles within the solar system. These dust particles, comprising remnants from the formation of planets and debris from comets, orbit the sun in the same plane as the planets.

Although it's long been thought that zodiacal light is caused by dust particles brought into the inner solar system by asteroids and comets, scientists using data from NASA's Jupiter-orbiting Juno spacecraft claimed in 2020 that some of that dust originates from Mars. The researchers suggested that Mars sheds dust into space, which is then influenced by Jupiter's gravity and dispersed throughout the inner solar system.

Seeing the faint column of light extending up from the horizon requires careful planning. With a bright moon gone from the twilight sky by Feb. 15, stargazers will have the best chance to spot the phenomenon if they find a remote dark-sky location far from urban areas. It's vital to have a dark sky towards the west and southwest, making coasts and islands a good choice.