New Horizons at Pluto

Dinwar said:
Titan is better--if there is life, it'll be at the surface of those organic solvent ponds.
Click to expand...
Problem is, Europa seems to have water oceans, and we know that such an environment is hospitable to life. Titan has lakes of methane and ethane: no liquid water - the rocks are frozen water. No life we are familiar with could endure such conditions.

It is far from certain that anything describable as life could evolve or survive on a body like that.
 
Craig B said:
Problem is, Europa seems to have water oceans, and we know that such an environment is hospitable to life. Titan has lakes of methane and ethane: no liquid water - the rocks are frozen water. No life we are familiar with could endure such conditions.

It is far from certain that anything describable as life could evolve or survive on a body like that.
Click to expand...

True, but we already have some evidence of metabolic processes on Titan.
 
Belz... said:
By the way: how can a body as small as Titan, way smaller than Mars, be able to hold such a thick atmosphere ?
Click to expand...

Probably because Saturn's magnetic field shields it from solar winds, which are also weaker at Saturn's orbit than at Mars's orbit.
 
Dinwar said:
I find the non-biological arguments to be somewhat lacking; not necessarily wrong, but I believe a scientific hypothesis needs to be more than "It might be something weird we don't know about yet".
Click to expand...

The flip side is that since alien life is the explanation we want to be true, we need to be extra cautious about not jumping to that conclusion.
 
Dinwar said:
http://www.nasa.gov/topics/solarsystem/features/titan20100603.html

There you go. It's a popular-press article, but you can find the peer-reviewed stuff pretty easily from there. I find the non-biological arguments to be somewhat lacking; not necessarily wrong, but I believe a scientific hypothesis needs to be more than "It might be something weird we don't know about yet".
Click to expand...
I take your point, but I also agree with the principle enunciated in the NASA article.

"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed."

ETA Ziggurat, I see you got there first.
 
Last edited:
Ziggurat said:
The flip side is that since alien life is the explanation we want to be true, we need to be extra cautious about not jumping to that conclusion.
Click to expand...

Agreed--I said "evidence", not "proof". It's curious, something worth looking into. I'm willing to accept that we've found stromatolites on Mars (if nothing else, being proven wrong would result in facinating science), but here I'm not willing to go that far. I'm just saying that no alternative I've yet seen offered rises to the level of a testable scientific hypothesis, and since it's the only place we've found any evidence of life outside th Earth we should go back to look for more evidence.

Craig B said:
I take your point, but I also agree with the principle enunciated in the NASA article.

"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed."
Click to expand...
I disagree. We shouldn't jump to such a conclusion, but "all non-biological explanations" is far too open-ended, and allows us to perpetually ignore evidence. I believe we should treat this hypothesis the same as any other.
 
To be clear, where possible I prefer to use Strong Inferrence--with multiple working hypotheses and tests that exclude all but one (a quick google will show you the paper). When I say "treat it as any other hypothesis" I mean let's figure out what possible options there are, a way to test those options, and put them to the test.
 
Just watched the excellent Sky at Night programme on New Horizons. One theory as to why the surfaces of both Pluto and Charon seem so young that I hadn't heard before is that the collision that formed Charon occurred relatively recently.
 
Pixel42 said:
Just watched the excellent Sky at Night programme on New Horizons. One theory as to why the surfaces of both Pluto and Charon seem so young that I hadn't heard before is that the collision that formed Charon occurred relatively recently.
Click to expand...

I proposed that a while back. :D It wouls explain much of what we see, I think.
 
Dinwar said:
Why not?
Click to expand...

Guy didn't say (he was quoted in an article... not sure I can find it again) but he said he'd rather rethink the science of how planetary surfacing works than consider a late formation.


(Googling "Charon recent formation")


Ah, there it is (top search result! Thanks, Google.) :

http://www.planetary.org/blogs/emily-lakdawalla/2015/07151720-first-look-at-new-horizons-pluto-charon.html

Here's the relevant part:

With both Charon and Pluto appearing so youthful, my first question about this was: is it time to consider the idea that the Charon-forming impact happened a lot more recently than we thought? I asked the question at the press briefing, but as it was my second question they didn't answer it. I've been polling scientists since, and while geologists like the idea, dynamicists say that the odds of such an impact happening late are "infinitesimal" (that's a quote from Bill McKinnon). I asked him whether a late impact is less likely than retaining primordial heat to the present day, and he -- a geophysicist -- seems to prefer rethinking his geophysics work to considering a late impact.
Click to expand...
 
Last edited:
So, no real reason given. I'm not at all convinced by one scientist's aversion to considering an idea--I'm too familiar with the Alvarez Hypothesis and the tectonics debates. Until someone gives me a solid reason, I'm going to continue to accept it as a viable explanation.

After all, we KNOW things hit each other, even back 100 ma. WE got hit 65 ma.
 
Yeah but not with anything near that size, however. Personally I don't think a recent collision is unrealistic, but then this was an opinion, not a science paper.
 
You must log in or register to reply here.

Back
Top Bottom