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This morning at dawn on the beach of Gavà, in the Baix Llobregat, it was possible to see impressive anti-crepuscular rays with the full moon, smaller than usual, as we see in this snapshot in Las Fotos de los Lectores de La Vanguardia.
The anti-crepuscular rays came from the Garraf massif, which rises in the Catalan Coastal Range and occupies a triangular area between the Llobregat valley, the Penedès depression and the Mediterranean. All a spectacle worth seeing.
The Garraf massif forms a group of low mountains. Orographically it goes from sea level to 593 meters from the top of Morella.
Anticrepuscular rays are similar to crepuscular rays, but seen on the opposite side of the sky from the sun. The anticrepuscular rays are almost parallel, but appear to converge at the antisolar point, due to linear perspective. They are most frequently visible at sunrise or sunset.
Crepuscular rays are generally much brighter than anticrepuscular rays. This is because crepuscular rays, seen on the same side of the sky as the sun, are scattered by atmospheric light and made visible as small angles.
Although anticrepuscular rays appear to converge at a point opposite the sun, the convergence is actually an illusion. The rays are actually (almost) parallel, and the apparent convergence is to the vanishing point at infinity.
