Dotini
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According to NASA, the season for noctilucent clouds is now upon us.
These electric-blue clouds are hanging 85 km above Earth's surface, at the edge of space itself. Their origin is still largely a mystery; various theories associate them with space dust, rocket exhaust, global warming--or some mixture of the three. One thing is sure. They're baaack ... for the summer of 2012.
Observing tips: NLCs favor high latitudes, although they have been sighted as far south as Colorado and Virginia. Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.
http://spaceweather.com/ <--archive 6/14/12
http://science.nasa.gov/science-news/science-at-nasa/2003/19feb_nlc/ <-- science and history of noctilucent clouds
Respectfully submitted,
Steve
These electric-blue clouds are hanging 85 km above Earth's surface, at the edge of space itself. Their origin is still largely a mystery; various theories associate them with space dust, rocket exhaust, global warming--or some mixture of the three. One thing is sure. They're baaack ... for the summer of 2012.
Observing tips: NLCs favor high latitudes, although they have been sighted as far south as Colorado and Virginia. Look west 30 to 60 minutes after sunset when the Sun has dipped 6o to 16o below the horizon. If you see luminous blue-white tendrils spreading across the sky, you may have spotted a noctilucent cloud.
http://spaceweather.com/ <--archive 6/14/12
http://science.nasa.gov/science-news/science-at-nasa/2003/19feb_nlc/ <-- science and history of noctilucent clouds
Respectfully submitted,
Steve