There's a new "star" in the sky, and it's taking the twinkle out of all the others. With a little help from the Lawrence Livermore National Laboratory in California, the Keck Observatory in Mauna Kea, Hawaii, has a brand-new laser that projects a yellow spot on the sky 100 kilometers above Earth. The spot from the 18-watt laser is too dim to be seen with the naked eye, but bright enough to help the Keck II telescope focus clearly through atmospheric turbulence, which makes stars twinkle and blurs astronomical images.
The meter-wide blotch, visible because the laser hits debris from micrometeorites, "looks slightly fatter than a star," says Livermore's Claire Max, the principal investigator for the laser project. While focusing on the virtual star, telescope technicians can adjust Keck II's deformable mirror, which continually flexes to compensate for atmospheric turbulence. No word on whether it does any good to wish upon the artificial star; Jiminy Cricket could not be reached for comment.