The sharp-eyed Jon Lomberg writes with a correction to today’s story on Xena and its moon Gabrielle. Specifically, my statement that adaptive optics ‘bounces’ the light of a laser off the atmosphere to create an artificial star used in refining the telescope’s images. Lomberg rightly points out that what the laser actually does is to excite sodium atoms at a specific height. The glow from this excitation is then tracked and used to adjust for atmospheric distortion. The results, as we have seen, are nothing short of spectacular.
What’s ahead for adaptive optics? “A future improvement of the technique,” writes Lomberg, “would use different lasers to excite other elements at other altitudes, thus giving a more detailed profile of distortion in the atmosphere resulting in more precise adjustments.”