Zodiacal lights: what is this phenomenon visible in the sky and how to observe it?

No need for a telescope, or even binoculars, your simple eyes will suffice! In mid-March 2023, and for a few weeks, it will be possible to observe zodiacal lights in the sky.

“It’s a very nice phenomenon”, enthuses withnews.fr Gilles Dawidowicz, vice-president of the Astronomical Society of France (SAF). “These lights take the form of a delta, the bottom of the triangle of which is on the horizon and the point of which soars perpendicularly into the sky. »

dust from comets

The zodiacal lights are rather lights that can be distinguished. This luminous halo is produced by the light of the Sun which is reflected by interplanetary dust, which is infinitely small (less than one millimeter).

For a long time, these particles were thought to be asteroid dust. Now, the scientific community thinks they are associated with comets that leave tiny debris in their wake.

Far from light pollution

We see them in the spring, after sunset, “when the zodiac (zone in which the planets of the solar system make their apparent course around the Earth, editor’s note) is perpendicular to the horizon”, according to Gilles Dawidowicz. In this period of equinox, which will take place on Monday March 20, this phenomenon is even more visible.

To see it, there is one condition to respect: get as far away as possible from light pollution. “In town, it is impossible to see anything, underlines the vice-president of the SAF. If you are in the mountains or by the sea, you are more likely to enjoy it. The moon, the clouds or even the mist are not welcome. You need a completely clear sky.

Looking west

If so, point your gaze due west, towards the horizon, just after sunset. If after 15 minutes, the soft glow has not faded, it is because we are in the presence of the zodiacal light.

“You can even take a picture with your smartphone, insists Gilles Dawidowicz. Preferably with a wide angle and a pause of several seconds. And open your eyes wide.

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