There seems to be confusion in some groups about "sending" the Hubble Space Telescope (HST) to Pluto or Neptune or whereever. Yes, HST is a spacecraft, but it does NOT travel away from Earth - it is always in orbit around the Earth. This is different from the Voyager or Galileo spacecraft, which do go to the planet they study. HST is a telescope that we will point at whichever planet or planets you choose to study.
HST has already looked at least once at each of the planets we are discussing. You REALLY should look at a picture of each of them, so that you know the kind of data you are going to get. New pictures of Neptune will look something like older HST pictures of Neptune, *not* like Voyager pictures of Neptune. New pictures of Pluto will look like older HST pictures of Pluto; the resolution (quality) will not be any better. It is important that you keep this in mind!
So why should we look at any of these planets again? Because all of them change! As a Neptune advocate, I've explained why I think it is a great target: it is far enough that you really need HST to study it properly, but it is big enough that you get good pictures. Its clouds change very quickly, and we don't understand how, when, or why. With Neptune, you are guaranteed to see something interesting, even in just one orbit.
But I think all the planets you are discussing are neat. The atmosphere and surface of Pluto may be changing as it moves further from the Sun. There may be new clouds on Uranus as its equator gets sunlight for the first time in many many years. And Jupiter is a target of intense interest right now, due to the Galileo Mission and the comet crash that happened last year. No matter which you choose, you will learn interesting things! Good luck during this final week of discussion.
Heidi Hammel, Planet Advocate
P. S. We are still working very hard on the new Neptune data we got - it turns out that it was the second orbit that was ruined by the loss of lock, not the third like I originally thought. I still don't know if there's a new Dark Spot or not, because we have been working very hard on the "navigation." This means figuring out exactly how to turn the positions of clouds in a picture into real latitudes and longitudes on Neptune. This process is complicated, it depends on the exact timing of the picture and where Earth is, where Neptune is, and where the Space Telescope is in its orbit around the Earth at that precise time. This part of the work is sometimes tedious and frustrating, but it is necessary to really understand what is in the images. Today and tomorrow we will be looking hard at the images of Neptune themselves. I'm looking forward to that!