Why only poor images of Pluto?

I was first disturbed by this Scientific American article
http://www.sciam.com/article.cfm?chanID=sa003&articleID=0004DCF0-8588-1F0C-97AE80A84189EEDF
and did some Googling
http://pluto.jhuapl.edu/plutocharon.htm
http://imgsrc.hubblesite.org/hu/db/1996/09/images/a/formats/print.jpg
Is the Hubble incapable of producing quality images of close objects? I’ve seen many a Hubble image of galaxies, in full color and crisp as can be, but here we have an object a billion times closer and it’s a dirty smudge.

My cynicism kicks in, of course, telling me there’s something truly interesting there that the government, which owns the Hubble, isn’t telling us. I don’t know of any other space telescopes, nor of any good images of the furthest planet. :slight_smile: Is Pluto just exceptionally faint and uninteresting?

It’s a billion times closer but also very faint and small. The Pluto-Kuiper mission, if it’s not killed, should get some much better images.

Try “exceptionally faint and not very luminous”.

Actually the crisp photos you’ve seen are enhanced. The actual Hubble photos are underwhelming to ordinary folks expecting vistas pulled from Star Trek. That said the Hubble still produces the best photos to be had of the Universe and is very useful to astronomers who know what they are looking at.

Pluto is very small (smaller than seven planetary moons including our own) and very distant from the sun. As such it reflects little light so the resolution isn’t going to be all that great.

Here is a fairly sharp, unenhanced photo of the the Pluto-Chiron system.

It may help to remember that galaxies are trillions of times bigger than Charon, lit from within by billions of stars. IIRC, recent “images” of the surface were made by measuring how the luminosity differed as it rotated, and re-constructing the surface from that.

I can’t remember what the Kuiper Express is gonna really do. First it was on, then off, then on… Nuts. It’s off.. Ok, but… there seems to be a replacement for it, launching 2006, arrival ~2015.

It would be nice to see Pluto up close. I hope it happens. :slight_smile:

The closest Earth gets to Pluto is 4.34 billion kilometers. Pluto is 2,301 kilometers in diameter. That’s about 1.9 millions times further then it is wide.

Let’s say we’re looking 12 billion light years away. That’s 252 quintillion kilometers. Using ratios we can see that looking at Pluto at its closest would be comparable to to looking at something 132 trillion kilometers across at the edge of the universe. That’s 0.000006 lightyears across. To compare our galaxy is about 100,000 lightyears across.

Then add in the fact that all those deep objects are streaming forth photons and Plutos just bouncing a few back from the sun make it incredibly hard to see.

You can join in the lobbying effort to preserve the New Horizons mission by visiting www.plutomission.com . Securing funding is a very close-run thing, and it won’t be this cheap and simple to visit Pluto-Charon in our lifetimes.

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