Nacreous Clouds
From my astronomy club, from the Australian Antartic Division, here is an article talking about these rare and colorful clouds found only in the most extreme cold cold environments:
These so-called nacreous clouds were situated high in the stratosphere, some 20km above the ground, and reveal very cold temperatures in the rarefied atmosphere.
Photographs taken by Renae Baker, a meteorological officer with the Australian Bureau of Meteorology at Mawson, on July 25 show delicate colours produced when the fading light at sunset passed through tiny water-ice crystals blown along on a strong jet of stratospheric air.
"Spectacular is an understatement. The clouds were such a special and welcoming sight now that the sun has just started to return near the end of winter. I am keeping my eyes towards the celestial dome and camera at the ready in the hope of some more."
"Our weather balloon measured temperatures down to -87ºC in the vicinity of the cloud layer. That's about as cold as the lowest temperatures ever recorded on the surface of the Earth. Amazingly, the winds at this height were blowing at nearly 230 kilometres per hour," Ms Baker said.
Clouds this spectacular are seldom seen.
You can find an entire photo gallery here:
