Uranus is surrounded by methane gas. This presents a problem for those of us who are interested in looking at it, since all that gas makes it hard to see what's really going on. Voyager and Hubble have the same problem, but new long-wavelength observations from the Keck II telescope in Hawaii have looked past the gas to examine Uranus in unprecedented detail.
Methane is opaque at visible wavelengths, which is why we're used to seeing pictures of Uranus that make it look like a nearly featureless orb in a lovely shade of blue. But all that we're really seeing is just the uppermost methane cloud layer in Uranus' atmosphere, and it turns out there's a lot going on underneath. The images at the top of this article, taken in the infrared (in which methane is transparent), show a spectacular amount of detail that makes Uranus look more like Jupiter or Saturn. In fact, these are the most detailed images of Uranus ever obtained from Earth.
To get these pictures, the Keck II telescope pointed a near-infrared camera equipped with adaptive optics at Uranus and snapped several hundred pics in quick succession. The sharpest of the bunch were layered on top of each other (after compensations for planetary rotation and cloud movement) to create the final images. Of particular interest are the poles (near the top and bottom); the south pole especially has a structure that closely resemble's the south pole of Saturn, seen here:
Nobody's quite sure where these cloud bands on Uranus come from or what they imply about the dynamics of the planet, but being able to see them in detail this good is the first step towards figuring all that out.