One technique to correct for the effects of the atmosphere is
to use
an adaptive optics system. This makes real-time corrections to the
distorted incoming wavefront using a deformable mirror. A number of
such systems are now in regular use. However, these are not yet useable
to observe large planets such as Mars and Venus, because adaptive
optics depends on the availability of a nearby guide star. A planet is
too large to be used as a guide star itself, and too bright to allow a
nearby star to be used. (However, adaptive optics works well for small
solar system objects - we have used it successfully to observe Titan
for example).
Left - Data taken with MUSIC on the ANU 40-inch (1m) telescope at Siding Spring during November 2005. At the top is the long exposure image of the star Zeta Ori. This image is about 2.7 arc seconds in diameter. The middle image shows the results of shifting and adding the individual frames. It shows a sharp core, but with an extended halo around it. The bottom image is the results of selecting the best frames only and combining these. The halo is much reduced and a sharp core with diffraction rings can be seen. (Observers Jeremy Bailey and Andrew Smith).
MUSIC 2
A new version of the MUSIC system is now under development. This will use an electron multiplying CCD (EMCCD) camera, providing fast readout with essentially zero noise.
Right - Image of the lunar crater Clavius, also taken with the ANU 40-inch telescope after (top) and before (bottom) processing to select and align frames. (Observers Jeremy Bailey and Andrew Smith).
