Alla vigilia del X STARPARTY del Centro Italia regaliamo ai visitatori del nostro sito una straordinaria e rarissima immagine di un red flash lunare. Esso si verifica con le stesse condizioni di fisica atmosferica del più famoso raggio verde.
La foto ci è stata pervenuta dal famoso astrofotografo #Miguel Claro (#TWAN) e lasciamo alle sue parole la descrizione:
“The image shows the full moonrise of last June 24, 2021, vividly orange in color above a hill made by rocky wastes from an extraction of marble, in Borba. In the foreground, blurred greenish hues belongs to a vineyard which is out of focus in the frame for being not faraway from my 600mm telephoto lens. Above the horizon, a sequence of shots shows the moon rising while seems to immerse into a layer of strong temperature inversion, where warm air is above colder air, creating the right conditions to show a rare phenomenon known as lunar “red flash”. On the second moon of the still photo sequence, is visible a red flash below the disc, appearing detach from the main body itself. Expert Les Cowley explains on his Atmospheric Optics website, “when crossing the layers, light rays bend so that they are reflected up and down. This phenomenon is the result of mirages and color separation. We usually see a green flash when the Sun or Moon dips down into the inversion.The near horizon moon has an upper green rim (green because much blue light is scattered away) and a lower red rim. A mirage is needed to magnify these into a green or red flash. The “Etruscan Vase” or “Omega mirage” is formed by refraction across the temperature/density gradients of warm air beneath cooler.”
Qui il video della formazione del red flash:
Moonrise Crossing an Inversion Layer Showing the Rare Lunar Red Flash
La rubrica #OPOD è redatta da Marco Meniero per conto del #GrAG
#moon #redflash #etruscanvase #omegamirage #luna
