Discover the cosmos!
Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2026 April 25
Explanation:
This seaside
sunset offered
a surreal experience, captured
in a sea and skyscape from the west coast of
Sardinia, Italy, planet Earth.
The Daliesque scene
is a composition
of sequential exposures made with a camera and long telephoto lens.
The Sun is
not
melting, though.
Its shifting and fluid appearance as it nears the
horizon is caused as refraction along the line of sight
changes and creates distorted images or
mirages of the
reddened solar disk.
The changes in atmospheric refraction correspond to
atmospheric layers
with sharply different temperatures and
densities.
Another famous but fleeting effect of atmospheric refraction produced
by a long sight-line to the setting (or rising) Sun is
often called the green flash.