Zodiacal Light

Zodiacal light is light that is reflected off of dust, planets and other matter that lie along the ecliptic plane. It is very difficult to see or photograph, and conditions must be near perfect to see it.

Facts about Zodiacal Light

  • It is light reflected off of material found along the ecliptic plane
  • It is best viewed at the fall and spring equinoxes
  • Seeing it requires minimal light pollution from natural and artificial sources

What is an Ecliptic Plane?

An ecliptic plane is the relatively flat plane in which most of the material and objects in a given solar system orbit the central star or stars.

How is an Ecliptic Plane formed?

When a solar system first begins to form, it is essentially a large cloud of dust and matter. As the dust cloud begins to organize, a star or stars are born, and planetesimals are formed as well. Eventually the cloud collapses into a flat plane. This collapse is believed to initialize the orbits of the materials around the star.

In our case, the star is the Sun. All of the planets and asteroids orbit the Sun on or near the ecliptic.

Ecliptic Plane and Zodiacal Light

Much of the material in the ecliptic reflects a certain amount of light that can be observed on Earth. However, the light reflected is much more diffuse than other objects we are used to seeing, such as the moon, stars and comets. This is because the light is being reflected off of dust particles rather than large objects.

Viewing Zodiacal Light

Because it is so diffuse, it is much more difficult to see! Observers should attempt to look for it around the spring and autumn equinoxes, when the ecliptic shows up high in the sky. In spring, try to see it in the western sky after dusk. In fall, the opposite is best. Try to find it then in the eastern sky before dawn.

Attempts at viewing this phenomenon should be done when there is a new moon if possible, and city and street lights should be minimal to none. Good luck and happy zodiacal light hunting!