DISCOVERY NEWS: EARTH’S HIGHEST BLUE ICE OVER IRAQ AND UZBEKISTAN
Last June 13 the crew of the International Space Station spotted these shiny, icy wisps above western Iraq and Uzbekistan in the mesosphere, an area of Earth’s atmosphere above the stratosphere but below the thermosphere.
The clouds are described as noctilucent, or night-shining clouds and are more commonly seen in the northern hemisphere during late spring and early summer. We can see them at night long after sunset as bright strands, waves or webs shining against the night sky.
The clouds are also called polar mesospheric clouds that form about 47 to 53 miles overhead in the coldest parts of the atmosphere. Their ice crystals usually appear blue because Earth’s ozone layer absorbs their red wavelengths of light.
Source: Discovery News June 26, 2012