Omega Sun Illusion

June 03, 2024


Photographer: Marco Meniero
Summary Author: Marco Meniero

The Omega Sun Illusion (or Etruscan vase) is an example of a lower mirage, which consists of seeing the solar image take the shape of the Greek letter Omega. It's made up of the real solar disk, joined in the lower part to its virtual image reflected by the sea and by a layer of warm air just above the horizon. Jules Verne describes it like this: “… the deformation of the disk, modified by refraction, made itself felt little by little; it widened to the detriment of its vertical diameter, and recalled the shape of an Etruscan vase, with swollen sides, whose foot plunged into the water."

The deformations of the solar disk vary with its elevation above the sea surface and by the number of contiguous air layers adopted by the different thermal and baric gradients that happen to be present at the time of observation. Photo taken just before sunset on March 7, 2024, from Civitavecchia, Rome, Italy.

Photo Details: Nikon Z9 camera; Nikon Z400/4.5, plus Nikon Z2X lens; 1/5000 seconds exposure; 100 ISO; crop 1.5 X by Photoshop.
Civitavecchia, Rome, Italy Coordinates: 42.0924, 11.7954