Image: The adaptive optics lasers from Keck 2 (left) and Keck 1 (right) shining overhead. Photographer/credit: Andrew Cooper, W.M. Keck Observatory.
May 3, 2011 -- No, that's not a science fiction movie CGI space battle scene, it's actually the view that would have greeted you if you were standing between two telescopes atop Mauna Kea in Hawai'i last month. For the first time, both telescopes of the W. M. Keck Observatory fired their adaptive optics lasers into the night sky after Keck 1 had its state-of-the-art laser switched back on.
The Keck 1 laser was originally fitted and tested last year, but it required an upgrade so sufficient power could be transmitted from the laser to the telescope. Rather than using optical fiber to guide the laser light, a new system of tubes and mirrors (known as a 'free-space transmission system') have been installed. "As we demonstrated last month, it works, we can put full power in the sky," Andrew Cooper, electrical engineer at Keck Observatory, told Discovery News.
"There's still a fair amount of work remaining, some final testing and tweaking before the system is declared operational. We hope to have that done in the next couple months."
Adaptive optics lasers are used by some observatories on Earth to compensate for turbulence in the atmosphere. By firing a laser into the sky, the reflected laser light is received by hi-tech instrumentation that changes the shape of a deformable receiving mirror in real-time. This compensates for the optical aberrations that could render the most powerful ground-based telescopes useless. The result is a crisp image of stars, planets and galaxies that would otherwise have been left to space telescopes -- orbiting high above our troublesome atmosphere -- to capture.
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