Strange phenomenon in the Tahitian sky

Sister Anne, don't you see anything coming?

But what happened in the sky over Tahiti on Wednesday, February 28th at sunset? Where could this strange blue beam that seemed to be sent to us by the sun have come from? Was it a divine sign, a message from the little blue men, yet another hole in the ozone layer, or perhaps Goldorak playing with his new laser?

Rays often observed in Polynesia 

None of this, I assure you, and ultimately, the explanation is quite simple. When the sun is at or just below the horizon, the presence of convective clouds, Cumulus or Cumulonimbus, prevent sunlight from illuminating the sky normally. Shadows will then form, often blue, which seem to converge towards the illuminating star. Seen from very high up, for example from the International Space Station, these rays are all parallel. But seen from the ground, with the parallax effect, they seem to form a fan whose origin is the sun or the antisolar point which is diametrically opposite it. We then speak of crepuscular rays or anticrepuscular rays. The particularity of Wednesday's phenomenon was that the shadow was attributable to a single Cumulus, a typical cauliflower-shaped cloud. We therefore only had one crepuscular ray in the sky..

Same old story this Thursday morning

They say that the early bird catches the worm. This adage was proven true again this Thursday morning, as around 5:50 a.m., rays, this time anti-twilight, stormed the sky, painting a fresco worthy of the greatest artists. The spectacle lasted only a few minutes. As the sun quickly gained altitude, its light naturally managed to pass over the clouds responsible for this brief and futile apparition. 

Fantastic celestial vault

Nature, and the sky in particular, often offers us fabulous spectacles that we rarely pay attention to. It's such a shame. So get into the habit of looking up and contemplating. These strange celestial phenomena are well worth a look. And maybe even a little stiff neck...

I thank Christophe SERPE and Alice CHAMPES for the photos.