Some facts about the telescope:
Each mirror segment is kept stable by a system of active optics that adjusts its position, relative to adjacent segments, to an accuracy of four nanometers. This twice-per-second adjustment corrects any distortions due to gravity.
Both telescopes are also equipped with adaptive optics, which compensates for the blurring caused by turbulence in the atmosphere. This, combined with the light collecting power of two sizeable mirrors, and some pretty sophisticated instrumentation, means that the twin Keck telescopes can produce some incredibly detailed images of distant objects in the Solar System, that are almost on a par with images from space telescopes. The following are two good examples of what Keck can do:
Saturn's largest moon - Titan
Images showing the two sides of Uranus