Saw this on NASAs New Horizons web site -

"What would a human see on Pluto?

An astronaut (Plutonaut?) stepping from their spaceship onto Pluto's surface would quickly notice many unusual qualities of this alien environment ... thousands of stars are visible, even in daytime." (Ref: http://pluto.jhuapl.edu/overview/faqs.php)

Is it just me, or is that, at least, incredibly misleading?

According to http://ask.metafilter.com/23197/Dark...e-edge-of-town, "direct sunlight on Pluto is still a bit brighter than twilight on earth", which surely rules out seeing "thousands" of stars (unless, of course, you take precautions to hide the reflected light from the terrain (plutain?) entering your eyes). Pluto has the advantage of not having any atmosphere to speak of, but the adaptation of the eyes to the ambient light level must surely rule out seeing "thousands" of stars.

The other problem I see with that web site is their insistence on calling Pluto a planet -

"Pluto is the only planet in our solar system, unexplored by space probes".
"Pluto's gravity is weak so that it takes a large amount of fuel to go into orbit around the planet".
" ... making daytime on the distant planet much darker than a cloudy, stormy day here at home".
"Depending on which part of the planet the astronaut landed".
etc.

This is in spite of the fact that the site has evidently been updated since the redefinition of "planet".

I would tend to agree with you. The bright foreground, as well as the bright sun in the daytime sky would not allow your eyes to dark-adapt enough to see thousands of stars.

Maybe this was written before Pluto's demotion. But Nasa media gets things wrong sometimes. I was watching Nasa Educational Files on television and they said something like "This 98 kilogram backpack would only weigh 17 kilograms on the Moon."

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I think Alan Stern is behind the persistent use of the term "planet". He's kind of been in a perpetual hissy fit about it since the IAU ruling, even though the ruling is very much in line with a paper he co-authored on the definition of planets a few years ago.

Just my opinion. He made some really unhinged comments after the ruling and insisted that he would defy the ruling and continue to use the term 'planet' in regards to Pluto.

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"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

Yeah, I was involved in one of the arguments with him on one of the mailing lists we're both on . It is odd, especially give that (as you note) what we ended up with isn't actually all that different to what he suggested previously.

Well to be fair, everyone and his brother's guilty of hyporcrisy on this. Even Mike Brown wavered a bit after discovering Eris. After all, would you want history to record you as the guy who discovered planet ten, or the guy who got Pluto demoted? Still, he came round to the IAU's decision in the end.

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I think fish is nice, but then I think that rain is wet, so who am I to judge?

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

What did he suggest?

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Fiction has to be plausible. Reality is under no such constraint.

Yes, and I was critical of Mike Brown in this forum for that. To his credit, he did come back around to his original opinion.

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"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

That the 8 classical planets are qualitatively different than Pluto and the other large bodies in the Solar System, precisely because they dominate their orbits. The conclusion of the paper was that it was sensible to have only 8 planets.

This was a few years before New Horizons, I think, so I guess his opinion changed.

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"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

Alan Stern may be acting petulent and hypocritical, but he did wager $700 million of taxpayers' money on a mission to the ninth planet. He has to keep the public on side somehow. Saying Pluto is just a KBO ain't gonna do that.

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I think fish is nice, but then I think that rain is wet, so who am I to judge?

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

There's no "wager" involved here - the probe's going to find interesting stuff regardless of whether Pluto is a proper planet or not. In fact it's already worth the money paid IMO just for the Jupiter flyby stuff (which as usual returned more info about Jupiter than Galileo ever did).

Don't take baric's opinion for thatWe had this discussion before, baric, and you didn't defend your position at the time. I think you're probably wrong.

PS:OK, I missed this comment. Do you have some more info on that?

There is if the probe breaks down. It's a lot easier to justify losing $700 million on a quest to the ninth planet than on a cruise to take snaps at a hunk of rock. If New Horizons doesn't make it, I doubt there will be another attempt.

Here:

http://www.boulder.swri.edu/~hal/PDF/planet_def.pdf

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I think fish is nice, but then I think that rain is wet, so who am I to judge?

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

I meant, in support of the contention by baric

Didn't defend? I was involved heavily in that discussion for some time. After a while, you get tired of people arguing semantics and find something more constructive to do.

I have a tremendous respect for Alan Stern and what he has done for astronomy & planetary science. I am not going to rehash an old discussion about something I thought he was being inconsistent about at the time.

Everyone is free to read the paper he co-authored in 2000 and determine for themselves if Stern is making an case for 8 dominant planets in our system:
http://www.boulder.swri.edu/~hal/PDF/planet_def.pdf

To imply that I somehow couldn't defend my statement because I didn't reply for the umpteenth time to a post at the end of yet another long discussion thread is unwarranted, imo. Stern's words in 2000 speak for themselves.

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"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

ex-squeeze me?

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I think fish is nice, but then I think that rain is wet, so who am I to judge?

It's gotten to the point where careful investigation is needed just to tell parody from reality. I think that means reality is broken.- Noclevername.

I do want to comment on this one aspect.. that I agree completely. If calling Pluto a 'planet' is the best way to continue public support & funding of space exploration, I am for it 100%. Stern's tireless efforts to make New Horizons a reality greatly overshadow, imo, his reactions to the IAU ruling.

However, the Ceres/Vesta mission is counter-evidence that a planetary body does not need to be officially designated a 'planet' in order to be explored.

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"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan

IMO, it is warranted.They seem to speak for themselves, but are you guys reading them?From that paper that you guys are linking to:
Table 2. of the paper, near the last page, is "A Roster of Known Planets in Our Solar System By Type" and Pluto is included in the table, as is Jupiter and "Numerous KBOs".

I don't think you can use that paper to accuse Stern of hypocrisy. In fact, if that's all you got, I think you owe him an apology.

Like most people, you continue to confuse labeling with classification. Stern proposes calling any gravitationally rounded object a 'planet', including moons, Ceres and large KBOs, and then refines that proposition by detailing a "Dynamical Classification Scheme". In that section, he makes it very clear that the 8 classical planets ("uber-planets") are qualitatively different then other planetary bodies in the Solar System ("unter-planets") based upon their ability to clear their orbits of other large bodies. He and Harold Levison describe what is fundamentally the underlying premise of the IAU decision that he now rejects. The only difference is cosmetic -- the particular labels applied to each category.

This discussion is fundamentally not about what is labeled a 'planet'. It is about whether Pluto and other large KBOs should be placed in the same category as the 8 classical planets. And yes, Stern SPECIFICALLY refers to Pluto as a KBO in that paper and I cannot believe I am still having to expound yet again upon this very elementary concept.

And get this... Stern refines his classfication even further, labeling Pluto and other similarly-sized bodies as "Subdwarf Planets"! In a sense, he "demotes" Pluto even more than the IAU!

As I said, I encourage anyone interested to read the Stern and Levison paper and decide for themselves.

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"Barbarism is the natural state of mankind. Civilization is unnatural. It is a whim of circumstance. And barbarism must always ultimately triumph" -- Conan