BBC 'Laser star' enhances cosmic view

The world's largest optical telescope facility can now use an
"artificial star" to improve its vision.
The star is created with a laser, which is fired 90km into the sky to
make sodium atoms in the thermosphere glow.

This spot of light is then used as a reference to process and correct
the blurring effects of our turbulent atmosphere on astronomical
images.

More at http://news.bbc.co.uk/1/hi/sci/tech/4756346.stm

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