Could life survive if earth was knocked out of orbit

Assume earth was knocked out of orbit and we were flying through space aimlessly. Could life still survive? i think it could because we can use artificial lights to grow crops, so food wouldn’t be a problem.

Energy would be a minor problem as wind & solar power wouldn’t exist anymore but we’d still have oil, gas, water, nuclear and everything else. Then again, maybe we wouldn’t have water because i assume all the wind would go away so maybe rivers wouldn’t flow anymore, im not sure.

Radiation would be a problem, but im sure it could be adjusted for.

Cold too. Cold would be a major problem but im sure we could accomidate for it. We may have to restart society 100 ft underground but we’d still survive as far as i can tell.

So im assuming that unless we get hit by a meteor we would still survive.

No doubt the energy demands of living on Earth would be so high that most people would die before equipment could be made to made warm tracts of land to grow food. The remaining elite few who survive would be so few that they and their decendents could probably go pretty far on the remaining energy reserves. Especially if fusion is available.

The problem then might be that there would be few people around to make the tech advances needed to leave Earth or find more fuel. Likely, once the fuel runs out, that’s it. Or even more likely, the equipment to gather the fuel (oil rigs, hydrogen extractors, whatever) would break down and the people will fail to repair it.


See the earth is spinning. And being in this orbit it holds an atmosphere. That atmosphere contains the one thing it is absolutely positively impossible to live without. Oxygen.

The spin is a balance produced by the Sun, the weight of the plant, the moon, and the rest of the solar system.

Push it out of orbit. . .bye bye atmosphere. . .

Pretty much bye bye everything.

No…that is not correct at all. The atmosphere is held in place by Earths gravity and that’s it. The Sun and moon do little more than tug at it creating some slight tidal fluctuations and that’s about it.
If the Earth gets knocked out of the narrow orbital range where it can support life, the atmosphere will either get too cold or too hot and everything will die.

Maybe a handfull of people could postpone the enevitable for a few months by living in caves or sealed climate controlled bunkers or whatever but that’s about it.

Fritz Leiber, in his delightful short story, “A Pail of Air,” explored this question. He suggested that people nearby large nuclear reactors might survive…but he also described a small family of urban survivors, who turned their basement into an airlock. Each day, the kids would go outside and scoop up a pail of air (oxygen that had frozen and fallen as snow) to be melted slowly over the family stove. (Obviously, they had to wear home-made space-suits to go outside…)

[qb]hroeder[/qb]: Were you makin’ a funny? The earth’s gravity wouldn’t go away. The air wouldn’t fly off into space; it would freeze and fall as “snow.”


Uhm Hroeder that was pretty confusing, care to expand on it?

First off the atmosphere and the top most reaches of the ocean will freeze. There’s likely enough tectonic energy to keep deep sea vents working and so allow small scale colonies of life to life but not much else. Since the ambient temperature of the universe is about 4K the planet is rapidly going to freeze solid. Sure small scale caverns under ground with hydroponic gardens might work but you’d need to be able to continually recycle the local atmosphere, though I suppose you could “farm” the layers of solid oxygen and nitrogen on the surface.

And since you’re underground you don’t need to worry about radiation too much and the magnetic field of the earth would continue until the core solidified.

The weight of the earth, alone, doesn’t create the appropriate gravity to hold atmosphere in place. Multiple balanced systems are involved. This solar system would undergo some cataclysmic changes if the earth were pushed out of orbit.

What happens if the Earth stops turning? Or its rotational speed changes?

Uh, yeah it does. The mass a the planet determines the escape velocity. The average velocity of a gas is dependant on it temperature. Now, when the escape velocity is less than the average velocity of a gas, the gas escapes. That’s why we don’t see much He in the atmosphere, it evaporates. Not once in all this does the sun, moon, or the earth’s rotation come into play.

Yes it’s a simplification, there are always molecules possessing above average velocities, but their gross evaporation times are much longer.

As for the rest of the solar system, that’s a separate issue, but given the fact that the Earth has hypothetically been punted out into the gulf between stars, I think we can assume the rest of the neighborhood is screwed.

Curtains for all animals, humans included. And plants. But some microbes would survive. Some of those suckers have never depended on energy from the Sun at all. Some of them must have survived all of the great extinction events. They’ll be OK until the Earth’s core cools to below below 0 Centigrade and all the water is frozen.

Yup Wes, cold would be a bit of a problem - the atmophere would freeze. Nitrogen, Oxygen the lot.

Permanent night at -270 degrees? You’d be better off on Mars.

That’s a pretty dern massive sun we’re orbiting around…well, relatively speaking, more massive than me, not so massive compared to a quasar. Wouldn’t anyforce capapble of knockingus out of orbit around the sun pretty much kill all life on earth outright?

Missed this bit. Wes, rivers flow because water seeks the lowest point. It’s an affect of gravity not wind.

There is evidence that ther rotation of the earth is constantly slowing; millions of years ag a day was only 21 hours long.

There is no evidence whatsoever that this had any effect other than to make the days go by faster. The rotation of the earth has no relation on its gravity. If the earth were to stop pinning completely, you’d still have the same surface gravity. A non-spinning earth would become uninhabitable pretty fast, but for other reasons than not having gravity.

wind pushes rivers… spinning keeps the air in…

how do we survive now!?

I don’t really know the science side. But the failure to date of SETI makes me think that conditions under which advanced life can be maintained are quite narrow. Otherwise, folks from solar systems a couple hundred million years ahead of us would have long ago colonized much of the universe, and we would have heard their broadcasts by now.

Are we talking about some magical force that knocks earth out of its orbit while violating all laws of physics? If not, the point is moot because the amount of energy it would take to alter the Earth’s orbit that drastically would raise its temperature to the point where everything would be incinerated and the crust would melt.

So it would get really, really hot, then very, very cold. An interesting question is how long would it take for the last human to die? Say, if we had twenty years’ warning that some deity was going to make the sun go out, what could we do to extend our existence, and how far could we extend it?

One option might be the Moon. The Moon contains hundreds or thousands of miles of underground lava tubes which could be heated with nuclear power plants, and are probably large enough to house hundreds of thousands or millions of people. You could also do some massive tunnelling projects on Earth or build underground homes connected with heated tunnels. Certainly nuclear power would be required - a LOT of it. We’ve have to dedicate all our resources to mining, digging, large-scale hydroponic farming, etc.

I’ll bet we could build an infrastructure that could survive for centuries, but life would be very, very tough.

It seems the key issue is how long the Earth’s core would stay warm. As long as it does, then human life could continue underground. Oxygen could be extracted from the rocks or mined from the surface. Water could be pulled from the frozen oceans. Food could be grown hydroponically. Except for being underground all the time, life could be quite comfortable.

The only significant variable that affects the Earth’s gravitational pull is the mass of the Earth. The rotation of the Earth, the presence of the Moon, Sun, and the rest of the planets do not significantly affect this.

You shouldn’t post in GQ if you have no idea what you are talking about.

With respect to the OP, the big problem is that the oceans and the atmosphere will freeze. Oh, and the entire ecosystem is going to collapse. :frowning:

Nope… A fly-by by a large rogue planet (yes, doggit, I did just misspell it as “rouge planet,” but caught it in time…) Ahem, a fly-by by a 100 x Jupiter-sized mass, passing through the solar system, could disrupt the earth’s orbit without causing the passage of that much energy through the earth’s surface. (A lot of earthquakes, yes; crustal melt-down, no.)

It could happen. You’re right, in that such a fly-by would be extremely unlikely to be so kindly, and such a near-collision would be much more likely to crack the crust and mantle, and to throw the earth into a nasty elliptical orbit.


I’d have to go along with zimaane. Assuming we had some warning, we could dig deep enough and possibly establish colonies that relied on geothermal energy.

Couple of other questions:
Would nuclear reactors be welcome in underground cities?

How long till the core cooled off? I would guess, in this scenario, we could continue to dig deeper and deeper as the core cooled in order to stay warm. But how long till the heat really goes out? Millions of years? If that’s the case, then humanity could continue to exist long enough to evolve into something completely different and more suited for this type of existence. Or, provided we preserved enough data, we could exist long enough in order to find a way off this interstellar tumbleweed and try to find a new home.

There is evidence that ther rotation of the earth is constantly slowing; millions of years ag a day was only 21 hours long."
I’ve never heard this. what evidence shows this?