Temperature of interestellar planets

[masbtt]

I have read that the surface temperature of a rogue planet (planet without star) can be higher than 0º C if it has enough atmosferic presure. Is that true?<br />If so, they could be more suitable for life evolution as they dont have to face periodical extintions caused by the impact of meteors.

 

[vogon13]

No 'rogue planet' can have a temperature below 2.73 K anywhere in our universe, regardless of it's atmosphere.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[Aetius]

Not to be nitpicky, but you mean Kelvin scale, right?

 

[vogon13]

Thanx, morning Java Jolt hadn't kicked in yet.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[alokmohan]

Why we cant go below 0 degreek,thats all.

 

[mithridates]

Yep, here's a pdf on the topic:<br /><br />http://www.gps.caltech.edu/faculty/stevenson/pdfs/interstellar_planets.pdf<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p>We thus see that bodies with water oceans are possible in interstellar space. The<br />“just right†conditions are plausibly at an earth mass or slightly less, fortuitously similar to<br />the expected masses of ejected embryos during giant planet formation. For a 50/50 ice-rock<br />body, the ocean is very deep and may be underlain by high pressure phases of water ice<br />with a rock core at still greater depths, but bodies with earthlike water reservoirs may have<br />an ocean underlain with a rock core. Either way, these bodies are expected to have<br />volcanism in the rocky component and a dynamo-generated magnetic field leading to a<br />well-developed (very large) magnetosphere. Despite thermal radiation at microwave<br />frequencies that corresponds to the temperatures deep within their atmospheres (analogous<br />to Uranus10) and despite the possibility of non-thermal radio emission , they will be very<br />difficult to detect. If, as many have suggested12, life can develop and be sustained without<br />sunlight (but with other energy sources, plausibly volcanism or lightning in this instance)<br />then these bodies may provide a long-lived stable environment for that life (albeit one<br />where the temperatures slowly decline on a billion year timescale). It is even conceivable<br />that these are the most common sites of life in the Universe.<p><hr /></p></p></blockquote> <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[alokmohan]

Far fetched.

 

[mithridates]

Oh. <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[nexium]

A white dwarf star does not cool much in a billion years, but Earth land areas typically cool about one degree f per hour from sunset to sunrise. A very thick green house gas atmosphere would be necessary, plus 100 times the heat that comes from the interior of our Earth to maintain liquid water long term, in my opinion. Neil

 

[danhezee]

what if the planet was the size of Jupiter and had moons similar to jupiters? <div class="Discussion_UserSignature"> </div>

 

[kelvinzero]

The inside of the earth is still way hotter than the surface. Would this be different for Rogue planets? I was shown a graph just recently that suggested a mere 2km beneath mars's surface it was hot enough for liquid water also.<br /><br />Since there is no solar energy, the surface is no more useful for life than other locations. You still need something like volcanic energy to power the life though.<br /><br />Although life can be powered by volcanic vents, having the entire surface of a planet populated provides a much larger area for the continual experiments of evolution to get lucky and achieve the next breakthrough that overruns the planet with an improved version. A billion volcanic vent sites that cannot exchange genetic material are not equivalent to one biosphere a billion times the size.

 

[mithridates]

Yes, though I think the argument made in that paper (or maybe another one I saw elsewhere) is that without a star to blow the atmosphere away rogue planets would all have much thicker atmospheres on average and that that would make up for the lack of a star. <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[alokmohan]

What you conclude?

 

[kelvinzero]

Ah yes, that is what I got too. More chance of liquid water specifically on surface due to thick blanket of hydrogen.<br /><br />This might make up for the lack of a star in the sense of keeping oceans liquid, but heat isnt enough. For life you need energy that can be exploited to do work. That means you need sunlight or hot <i>next to</i> cold (volcanic vents)

 

[mithridates]

The page also suggested lightning along with volcanism as another source of energy. I can't think of any others myself. <div class="Discussion_UserSignature"> <p>----- </p><p>http://mithridates.blogspot.com</p> </div>

 

[heyscottie]

But isn't lightning more or less solar power? Lightning cannot be an actual power source; it is caused by energy input from elsewhere. It could be caused by volcanism as well, so it could exist on a hypothetical rogue planet, but it still isn't the source...

 

[CalliArcale]

Lightning is a static electrical discharge. It is not generated directly by solar power, but some of the processes that generate it derive their power ultimately from the sun -- namely, thunderstorms. However, it is also generated by other processes, such as volcanism. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[kelvinzero]

This aint an informed opinion but maybe a giant peizo electric effect? Could come from tidal forces squeezing quartz?<br />http://en.wikipedia.org/wiki/Piezoelectricity#Naturally_occurring_crystals<br /><br />What about all the storms on jupiter? what powers them?<br /><br />Perhaps also some interaction of the magnetospheres of planets could strip charge off upper atmosphere?<br /><br />In any case it all seems to come from draining the gravitational potential of the planet or orbiting planets... Ive always liked the idea of an orbiting moon sized 'fission sun' but that would come under the freak of nature category.

 

[alokmohan]

Title is interstellar planets.

 

[CalliArcale]

And that's why I pointed out that lightning doesn't have to be generated by a solar-powered process, so theoretically, it could occur on a rogue planet. <img src="/images/icons/wink.gif" /> But you're right -- we are at risk of going offtopic on lightning.<br /><br />To bring us back to the point, I don't think there's much chance of lightning on rogue planets. I would think most rogue planets would be "dead". On the other hand, that's what we all thought about Pluto/Charon too, and there's evidence they may actually be active. There's also the possibility of tidal forces keeping a system of rogue planets warm enough to be geologically active. That could be very cool indeed. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[tdamskov]

I'm wondering if an atmosphere is any use at all. The surface of an interstellar planet wouldn't be very interesting energy-wise.<br /><br />More plausible would be a Europa like layer of ice on a deep ocean. I'm not sure how the math would turn out and how thick the layer would have to be to effectively keep in the heat. But at least it opens up the possibility of life around volcanic vents, similar to Earth.<br /><br />Anyone wants to hazard a guess how long an interstellar Earth type planet would be able to retain heat with a deeper ocean covered in ice?