QUESTION:
What new aspects have you discovered of Uranus that you did not observe before
the Hubble Telescope?

ANSWER from Sanjay Limaye on March 15, 1996:
I am assuming that the question is referring specifically to what we have
learnt about Uranus from HST images that we did not know before (such as
from Voyager 2).

HST has not made very many observations of Uranus itself yet, although they
are scheduled for future.  The observations to date have focussed on moons
and rings of Uranus, which also provided some images of the planet itself.
These images did show some new cloud forms that were not seen from Voyager.
Thus, at least we can guess that the atmosphere of Uranus produces clouds
that change over time.  Future observations, taken more often, and at a
variety of wavelengths, hopefully will tell us more about Uranus.  Also, the
illumination of Uranus by the Sun is now different from when Voyager saw it
nearly ten years ago due to the orbital motion of Uranus, so perhaps we may
see more differences in the clouds.  One main puzzle is why does this
atmosphere show so few discrete clouds?  All other gaseous planets show far
more isolated cloud forms than Uranus, which is mostly covered with more or
less uniform cloud/haze structure, with some differences in the methane
abundance (or, cloud structure) latitudinally.