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Credit & Copyright: Julien Looten
Explanation:
Are lasers from giant telescopes being used to defend the Earth?
No.
Lasers shot
from telescopes are now commonly used to help increase the accuracy of astronomical observations.
In some directions, Earth atmosphere-induced
fluctuations in starlight can indicate how the
air mass over a
telescope is changing, but in other directions, no bright star exists.
In these directions, astronomers can create an
artificial star with a
laser.
Subsequent observations of the artificial
laser guide star can reveal information so detailed
about the changing blurring effects of the
Earth's atmosphere that much of it
can be removed by rapidly flexing a telescope's mirror.
Such adaptive optics techniques allow high-resolution ground-based observations of
real stars,
planets, and
nebulas.
Pictured here, telescopes at
Paranal
Observatory in
Chile
study a colorful sky filled with green
airglow and the
Magellanic Clouds on the left, red
airglow on the right,
and the majestic central band of our
Milky Way Galaxy
arching across the center.
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NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.
Based on Astronomy Picture
Of the Day