Saturday, June 30, 2007

Nobody Can Explain The Mystery Of The Night-Shining Clouds

They street term is "night-shining" clouds. And it's far more poetic than the scientific term, "noctilucent", for one of the world's greatest, and most beautiful mysteries.

So far, there is no peer-reviewed, or even unanimous, explanation for why high-floating clouds are glowing spectacularly at night, usually coming from out of the Arctic.

There's a few theories - volcanic ash, ice crystals sandwiched between layers of atmosphere, space dust.

But when in doubt of an explanation that makes sense, you can always try this one : climate change.

From Live Science :

The clouds are on the move, brightening and creeping out of polar regions, and researchers don't know why.

"It is clear that these clouds are changing, a sign that a part of our atmosphere is changing and we do not understand how, why or what it means," said atmospheric scientists James Russell III of Hampton University in Hampton, Virginia.

"These observations suggest a connection with global change in the lower atmosphere and could represent an early warning that our Earth environment is being changed."

The clouds form 50 miles above the Earth’s surface, in an upper layer of the atmosphere called the mesosphere. The puffs of water vapor and crystals appear during summer months above the Northern Hemisphere's pole as well the Southern Hemisphere’s pole in summer.
The mysterious clouds aren't new. They were first recorded back in 1885, but weirdly, they are now on the move, spreading further across the planet, through the upper atmosphere, as the decades pass.

Night-shining clouds were observed, and photographed, from the International Space Station back in 2003. Astronauts described them vividly, as visions of immense beauty :
They hover on the edge of space. Thin, wispy clouds, glowing electric blue.

Some scientists think they're seeded by space dust. Others suspect they're a telltale sign of global warming.

A century ago the clouds were confined to latitudes above 50 degrees; you had to go to places like Scandinavia, Russia and Britain to see them. In recent years they have been sighted as far south as Utah and Colorado.

A view of the night-shining clouds from the International Space Station, back in 2003

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