View Full Version : How cold would the Earth get?

Tom Mazanec
2013-Jan-05, 12:19 PM
Suppose the sun just disappeared. How cold would the Earth's surface get till geothermal heat would stabilize the temperature? Would the atmosphere freeze? How long would it take to level out?

Jeff Root
2013-Jan-05, 01:59 PM
I believe there was a thread on this same question just a
few months ago. My own offhand thoughts are that most
of the surface is pretty well insulated from the interior, so
it would cool off to nearly the temperature of Space. The
atmosphere would freeze, I suppose leaving helium still
gaseous. I think the atmospheric temperature would fall
to zero Celsius everywhere on the planet within a week,
certainly in two weeks. Nitrogen might start freezing out
in less than two months. The atmosphere would probably
be completely gone in under a year. The oceans would
freeze over by then but would not freeze solid, because
of the geothermal heat.

-- Jeff, in Minneapolis

2013-Jan-05, 04:55 PM
There is a short story, "A Pail of Air", by Fritz Leiber, that is a very good description of attempting to survive in such an environment.

2013-Jan-06, 03:14 AM
That classic is indeed a must-read. I read it once when I was a kid and never forgot it.

As for what it would be like "IRL", I don't think it would be quite as bad as the story. AFAIK, interstellar gas temps are well above the cosmic background temperature; I'm guessing it would get cold enough for the inert gases to condense and freeze, but too warm for hydrogen (let alone helium) to do the same. As others have stated, geothermal heat would keep the deep layers of the ocean and areas of the continents above bedrock warm enough for some life for a pretty long time, probably much longer than the current remaining time of the Sun's life.

2013-Jan-06, 03:39 AM
I heard it as a radio play as a child--but only about the last two minutes.

2013-Jan-06, 07:04 AM
I heard it as a radio play as a child--but only about the last two minutes.

You can listen to it again, (http://archive.org/details/xminusoneotr)from the beginning.

Nick Theodorakis
2013-Jan-06, 06:45 PM
"A Pail of Air" is online, btw:



2013-Jan-07, 03:22 AM
You can listen to it again, (http://archive.org/details/xminusoneotr)from the beginning.

Thanks, I have just down loaded it.