At middle latitudes or high altitudes in autumn conditions arise in which we can observe ribbons ice formations. In late October and early November 2011 immediately above the ground around the stems of some plants appeared icy ribbons.

Fig. 1. Ice ribbons

Often we can see an iridescent crown (ring or halo) around the Moon. From time immemorial, this phenomenon is related to the culture of many nations, a harbinger of cold, rain or snow. But often the beauty of nature is short and portends bad weather.

Fig.1. Iridescent crown around the Moon (06 Nov 2011).

"Ever gazed upon the green flash, Master Gibbs?"
"I reckon I've seen my fair share. Happens on rare occasion; the last glimpse of sunset, a green flash shoots up into the sky. Some go their whole lives without ever seeing it. Some claim to have seen it who ain't. And some say... "
"It signals when a soul comes back to this world, from the dead!"

― Hector Barbossa, Joshamee Gibbs and Pintеl to Will Turner. Pirates of the Caribbean – At World’s End

The concept of an internationally standardized system of units (astronomical units or astronomical constants) is one of the most fundamental in experimental science. Here you can found some basic parameters and information of the Sun. This information is in accordance by XVIth General Assembly, Grenoble, France, 1976 (pdf) of International Astronomical Union.