Scientists don't take kindly to the notion that luck plays a large role in achieving good results. It is well-thought-out experiments and plain hard work, not unpredictable luck that produce the best repeatable science. But even scientists might admit that with a new technique for taking high-resolution pictures of the sky, luck is the whole ballgame. Dubbed Lucky Imaging,1 this method could revolutionize the capability of ground-based telescopes.
An earlier Connections article discussed the value of having telescopes operating in space, free from atmospheric distortions.2 But, with the slow demise of the Hubble Space Telescope, astronomers will no longer be able to take pictures at visual wavelengths from space. The follow-on James Webb Space Telescope, scheduled to be launched in 2013, will work best at longer wavelengths. In anticipation, telescope builders have been working on a technique called adaptive optics to overcome this atmospheric problem for ground-based telescopes, but success has been limited. Enter Lucky Imaging!
The idea behind Lucky Imaging is not new. David Fried proposed the technique in 19783 and Robert Tubbs fully implemented and described it in 2003.4 A telescope in space is able to form a sharply defined image of an object where its resolution is limited only by the diameter of the telescope and the wavelength of the light. However, if the telescope is on the ground, density fluctuations in the atmosphere cause distortions in the image so that it becomes fuzzy.
Since these fluctuations typically occur at a rate of about a hundredth of a second, it is possible, with a faster shutter speed, to snap a picture and essentially freeze the image. After capturing a series of such images, by luck, some of them will have much smaller distortions than others. Selecting those "lucky" images and averaging them together yields a final result with much higher resolution than would have been obtained using all the images.
The results of Lucky Imaging are stunning. A team of astronomers from Caltech and the University of Cambridge used the technique combined with adaptive optics on the 200-inch Palomar Telescope to obtain images of the Cat's Eye Nebula (NGC 6543). They achieved greater detail than even the Hubble Space Telescope.5
Astronomers have been able to use this technique only now because recent improvements in the performance of CCD (charge-coupled device) detectors have achieved near perfection in efficiency and quality. These detectors are also available in off-the-shelf cameras so that amateur astronomers can do Lucky Imaging with equally stunning results.6
RTB scholars celebrate and eagerly await the results of the new technology. With any luck, more-detailed images of our own galaxy as well as external galaxies will display increasing evidence for supernatural design.