"Ground-based astronomy could be impossible in 40 years because of pollution from
aircraft exhaust trails and climate change, an expert says.

Aircraft condensation trails - known as contrails - can dissipate, becoming
indistinguishable from other clouds."

More at http://news.bbc.co.uk/1/hi/sci/tech/4755996.stm
--
Nick in Northallerton
Also @ www.whelan.me.uk
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