Description:
A laser beam is fired towards the center of the Milky Way.
Why fire a powerful laser towards the center of the Milky Way? Fortunately, this is not a sign of interstellar war. This is astronomers at the Very Large Telescope (VLT) site in Chile trying to measure the Earth’s changing atmosphere. By continuously observing atoms excited by the laser at high altitudes, which appear like an artificial star, astronomers can immediately determine the blurring effects of the atmosphere. This measurement information is fed back to the VLT mirrors, causing them to deform slightly to cancel out the blurring effect. In this case, the VLT is observing the Galactic Center, and measuring the atmospheric blurring in this direction is necessary. As for interstellar wars, from the perspective of the Galactic Center, nothing would be seen. In fact, this intense laser beam would combine with sunlight and, from the Galactic Center, would appear only as bright as a faint distant star.
NASA Website:
http://antwrp.gsfc.nasa.gov/apod/astropix.html
http://antwrp.gsfc.nasa.gov/apod/ap090816.html
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