Lonely ‘homeless’ planet found for the first time
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Even when the scientific payoff is limited, the payoff to the imagination is immense.
[1] A series of short stories by a Roger Williams, tagged localroger on kuro5hin, wrote back in the day. I gathered the parts together into an ePub suitable for iBooks. I'm checking with the author now to see if I can make it available. You can always read it on the kuro5hin site, linked from http://localroger.com/ (The Metamorphosis of Prime Intellect is something else entirely.)
That's to get to the stable point. It takes a while for the earth to cool down. Assuming 100m depth, ... I tried, but I couldn't figure out the physics. The frost depth in some parts of the world is over 2 meters, so a basement wouldn't be all that useful. Compare the temperature of -50C for winter in Siberia to -270C for the many years of the story. You'll also have liquid air leaking through any cracks and pooling in the bottom - the parts at least which don't drain to cover the frozen sea.
But how deep do you need to go to be ahead of the chill? I found a table in the "permafrost" page on Wikipedia, which linked to http://www.dtic.mil/cgi-bin/GetTRDoc?Location=U2&doc=Get... . That looks like it has enough details to figure out how long it would take for a surface temperature near absolute zero to penetrate 100m into the ground, causing an initial subsurface temperature of 12C to drop to 0C. Can you figure it out?
In any case, perhaps others might have survived in deep caves, using geothermal heat. It's doesn't mean that the people in this story couldn't have survived using some other means.
http://journals.ametsoc.org/doi/pdf/10.1175/1520-0442(1997)0... says that the the Antarctic Circle gets about 120W/sq. meter averaged over the entire year. That's about what I expected since sin(23.5 degrees)snow albedo of 0.63 months/12 months * 1000 W / sq. meter solar power -> 60 W/sq. meter. While not a lot, it's still appreciable.
Assuming everything is radiated out to space, Stefan-Boltzman says that (5.670373e-08)T*4 = 120 W/sq m. => T = 214K, which means Antarctica would have a overall average temperature of about -60C, if only due to solar heating.
Interestingly, "Other scientists have estimated that temperatures on any possible permanently lit spot [on the Moon] would be comparatively balmy, though still a frigid minus 58 Fahrenheit (-50 Celsius), give or take a little." This is in concurrence with my calculation.
Which means that solar heat alone is enough to explain why the temperature does not get to the -180C needed to liquify oxygen.
Not exactly sure what "temperature" refers to there, but Wikipedia tells me that Jupiter itself has a surface temperature of less than -100 degrees C. So even without a star, it's rather substantially warm. However, at Jupiter's distance, the solar radiation received from the sun is rather minimal anyway.
By the way, it looks like the entire book is available online; this[1] is a link to the section of ch. 24 that talks about these star-less planets and the possibility that they contain life.
First, he points out the "extremophiles" that exist on earth -- for example, organisms that live on the sea floor, where the heat from the sun is fully nullified. Despite the great atmospheric pressure and the lack of light and heat, life still thrives in these environments. One of the factors that facilitate life at these extremes are the geothermal processes (vents in the sea floor) which are purely disconnected from the events of the sun, and completely powered by our magma core.
As we know, many planets are suspected to have molten cores, which are the result of their formation and which will continue to remain such for billions of years (we will probably be wiped out by our Sol turning into a red giant before our the Earth's core will lose it's energy). As such, though it'd be near-impossible for life to survive on the surface of a planet that is not a part of any solar system, under the surface life could be bountiful.
1. http://books.google.com/books?id=o6OmdAFDTVQC&lpg=PA233&...
That's page 244, and from there until the end of the chapter (p.250) is all relevant to your comment.
Before the discovery of radioactivity invalidated the calculation, the fact that the Earth's interior is still hot was used by Lord Kelvin to set an upper limit of 40 million years for the Earth's age.
Once you scale up to gas giants these factors become even more important. Those planets retain a crap ton of heat from their initial formation and are comparatively inefficient at radiating it away into space. More so, they continue to generate heat through ongoing settling (raining of Helium down to lower levels of the atmosphere, for example).
I am barely qualified to call myself even an amateur astronomer, so sorry if I've misinterpreted anything.
edit: re-reading the passage, it sounds like it's a combination of both (bottom of p.245, 246).
Different kinds of radiation differ by how deep they penetrate matter. Simplifying a bit you can imagine that for every atom the radiation passes, there's a probability that it interacts / gets absorbed.
Radiation that passes thousands of kilometres of rock without interaction will have a rather low probability of interacting with a mere metre (or so) of human.
Larry Niven's Known Space books deal with this. They put a civilization of herbivorous creatures called Puppeteers on a group of sunless planets accelerating away from a catastrophe in the galactic center. One enjoyable aspect comes from the creatures' herd-like, risk-averse nature, a hold over from their distant past as prey animals. They dream of fleeing forever, enjoying a nomadic existence in the voids between galaxies.
It's been awhile since I've read the series, the Ringworld novels bored me.
Wish I remembered the author or title, and I wish even more that the author would expand it into a full-length novel.
Doesn't the very definition of planet imply rotation around a star or other celestial object?
The BBC article is a little better: http://www.bbc.co.uk/news/science-environment-20309762 And it links to the actual paper: http://arxiv.org/abs/1210.0305
In any case, if the official position is that a "dwarf planet" is not a planet then it's not hard to see that a "free floating planet" need not be a "planet."
The planet is in fact called CFBDSIR2149 and appears to be part of a group of very young stars known as the AB Doradus Moving Group. “This group is unique in that it is made up of around thirty stars that all have the same age, have the same composition and that move together through space. It’s the link between the planet and AB Doradus that enabled us to deduce its age and classify it as a planet,” researcher Lison Malo explained.
I find it fascinating that we have identified a group of stars that are (i'm assuming) moving in synchronous towards a general direction. I can only theorize that it was caused by perhaps a giant supernova that flung all of these stars/planets outwards but it does make you wonder what caused it exactly.
It says that the planet has a temperature of approx 400 degrees Celsius. That is hot. I would have expected it to be deadly cold, esp since it never managed to initiate nuclear reactions in its center. Why is that?
http://upload.wikimedia.org/wikipedia/commons/f/fc/Ceres_opt...
UPDATE: Here's its wikipedia page. 100 light years way from earth, so there is no way it's a photo. Also, wikipedia calls it a brown dwarf, which would explain the temperature: http://en.wikipedia.org/wiki/CFBDSIR2149-0403
By that time, our species should either be long extinct or have evolved into vaguely godlike space-beings.