A Full Perigee Moon
rose as the Sun set last Sunday.
At its closest to Earth it was, by just a bit,
the year's brightest and largest Full Moon
also known as a Super Moon.
Seen from Punta Piedras, Argentina and the mouth of the Rio de La Plata,
near Buenos Aires,
the Super Moon's light created this magnificent
Still, the size of a lunar halo is determined by the geometry
of six sided water ice crystals in planet Earth's high, thin clouds.
deflect the rays
of moonlight more strongly through a minimum angle of 22 degrees.
So this halo has an inner radius of 22 degrees, just like the halos
of the less-than-super moons.
Even more common than a Super Moon, beautiful 22 degree
halos can be spotted at any time of year.