Idea bouncing

[Gear]

Let's say the Earth, for whatever reason, flies out of orbit. Obviously, everyone dies, but that's beside the point. The Earth flies off, and after a lengthy period of time, starts orbiting another star, a hotter one, no less. It's not horribly hotter, but let's say the average summer temperature is 150 or so.

Given this, what do you think the world would look like?

[Celianna]

The icecaps would melt, rising the sea level, flooding most cities around the world. The ocean absorbs much more heat, and thus it gets even warmer. Humans and animals who can't take the heat would die off, going extinct. Cave creatures would flourish, since they hide from the heat, so you'll get a lot of 'white' creatures if they're never exposed to the sun.

Fresh water fish might die off too, while those who live in the ocean might fare better.

Basically, humans will die, fish and insects will try to live on. It'll probably look a lot like Water World.

[Desu_Cake]

Hmm. Well, presumably everything would have frozen when it flew off in the first place, so at a guess, it'd be mostly water, and what little land there is would be nothing but rock and dirt.

[papillon]

150 celsius would be a rather problematic temperature...

But yeah, everything would freeze. How _hard_ would the Earth freeze if there were no sun for a while? It depends on how long we're between planets really. If the event that caused the Earth to go wandering wasn't sufficiently catastrophic by itself, small pockets of humanity would survive for quite a while, being intelligent and capable of holing up and generating heat. Some very hardy plants could make it for a year or two of deep-freeze, as well as a few particularly nasty and hard-to-kill insects and so on, but mostly life would be limited to whatever people managed to pack into the Vaults and maintain. How much would make it depends a lot on how much time people had to prepare.

If things get cold enough and then heat up again, the stress will probably crumble most surface structures, but not everything. You'll have your small handful of relics to explore when you emerge from the vaults.

[Applegate]

I think he meant Fahrenheit, papillon; given he's American and all, it isn't weird that he might overlook mentioning something otherwise understood in his culture.

I think Desu_Cake presents a reasonable view in line with my own; Earth would likely have frozen over first prior to being completely defrosted, killing off all life on the planet except those capable of surviving extreme weather of both sides: once you've accepted -30 degrees celsius as the norm, going up to 60 degrees celsius will feel like murder. On the other hand, entering it from an accepted temperature of 50 degrees celsius, 60 degrees won't be immediately fatal.

Suffice it to say that I expect only creatures that burrow in the earth and/or are capable of surviving extreme weather conditions and/or are capable of adapting rapidly to changes in climate will have survived; provided the trek from one star to the other isn't a process of unimaginable time. The longer it takes to transition, the more likely life will be able to adapt to the lowering/rising temperature changes, up to a certain level.

[Aleema]

Well, it would be a completely different planet, that's for sure. This would cause the single greatest extinction in the world's history (and the largest already being 83% of all life). This would include most marine life and insects as well. The very atmosphere of the earth would change, if not from the ride over there, but from the lack of everything that produced the components (oxygen would go bye bye). I believe, in time, algae would regrow since life always finds a way, but we're talking millions upon millions of years to get even remotely close to what we had before.

[Crocosquirrel]

Well, for starters, it would be a lot drier than it is now. At 150F, the icecaps would be mostly melted, but that would take awhile to make happen. A lot of our flora would have a hard time as well. Now, did Luna go with it, or is it still parked in our old orbit? This opens up a whole new series of possibilities. Part of what keeps our day the length it is and our core molten is the moon's gravity.

Without Luna in her orbit, our rotation speed picks up by rather a lot, and the core cools considerably. In transit, everything freezes more or less solid, of course, so the buildings and whatnot would be preserved, at least for awhile. But when the air thaws again, all the freezing expansion will do a number on any kind of stonework or glass. Steel, on the other hand should survive the thawing process more or less intact. The oceans will rise as the temperature goes up, but the evaporation process will accelerate as well. The new atmosphere will contain a larger percentage of water vapor, making the surface rather warmer that the 150 degrees than you're talking about.

Depending upon exact circumstances, you have a thick, very wet atmosphere, and like as not a lot of rain in the evening and predawn hours.


Of course, this is primary conjecture, but most of the global warming research is close enough give us a start. Do you know the stellar class of the new star, and it's distance from Sol? That would make for better accuracy if I could make some educated guesses about temperature and transit time. The net effects on the planet would be huge. Too long out in space/without a moon, and vulcanism will stop altogether.

Also, what knocked it out of the system, and how much damage did it do? Even with humanity surviving underground, as Papillion suggests, a force sufficient to knock an object the size and mass of Terra out of her orbit would likely cause massive damage to anything on the surface, and most likely crush anything underground. As for survivors, think bacteria.

[Gear]

Yeah, I meant Fahrenheit. Sorry, I tend to forget when I'm speaking with people on a more international scale that we're the weird ones.

As far as life goes, I'm pretty much going to assume that everything's dead. Billions of years later, Earth finds another star, so the human race has completely died out. Upon reaching the new star and establishing an orbit, the temperature increases to 150F (or 65.5 C), and I suppose the possibility of life could return. But...I don't know. That whole "where did life come from" thing pops up at this point, and I may not even want to broach the topic.

And as I posted, DarkSpartan did, bringing with him a plethora of awesome information. So, let's say Earth throws its hat in the ring with Alpha Centari, maybe even entering into some bizzare three-way with Alpha, Beta, and Proxima. As far as what knocked the planet out of orbit, I'm still not sure. Something slamming into the planet seems like the most obvious, but could Sol itself been responsible, perhaps during its dying hour?

As far as Luna goes, would it be possible for it to have remained in orbit as the planet traveled?

[Crocosquirrel]

And as I posted, DarkSpartan did, bringing with him a plethora of awesome information. So, let's say Earth throws its hat in the ring with Alpha Centari, maybe even entering into some bizarre three-way with Alpha, Beta, and Proxima. As far as what knocked the planet out of orbit, I'm still not sure. Something slamming into the planet seems like the most obvious, but could Sol itself been responsible, perhaps during its dying hour?

As far as Luna goes, would it be possible for it to have remained in orbit as the planet traveled?

In theory, it could, if the same forces that kicked Terra out of her orbit were applied just so. So possible, but the maths are very scary. As far as Sol doing himself, I can give you a qualified maybe. Most likely, the planet would be scoured clean as the star advanced in it's death throes. Now, on the off chance that a pulse from the star did such a thing, it would clear out the inner planets whilst doing so, and at a substantial fraction of the speed of light.

Acceleration alone would turn all life on the planet into chunky salsa.

On the plus side, lots of coal and oil for the next inhabitants. On the down side, they would be extremely unlikely to be native to the planet except the old-fashioned way.

In that circumstance, the chances of Luna going along for the ride are higher, but the maths are still extremely ugly.

Now, assuming for a moment that Luna managed to go along and retain her orbit, the core would remain molten for considerable lengths of time.

Alpha Centauri would be a bad choice, as far as other stars to head for. I would *personally* take advantage of the immense speed supplied by our little buddy Sol, and go much farther afield. Chances are, the star in question would be new enough to not exist today, or if it does, exist in an embryonic state. At .5c (a rather reasonable speed under this scenario) you could get this chunk of rock quite a ways out in just a few millenia. There are a number of current stellar nurseries you can get to in that time.

Let's call ours... Margaret. Just because

The story goes something like this: Terra and daughter Luna go wandering off and wind up dropping in on Margaret. Margaret has a number of bright daughters, that we'll call Lucy, Eileen, and Nanami. Terra checks in on Lucy at a large interval, and slows down, and makes a smallish course change. She then goes and makes a closer visit to Eileen, who slows her down even more. Eileen provides a significant course change, which sends Terra very close to Nanami. Terra decides to stop for tea and crumpets, and winds up staying on permanently.

All the material from the original civilization (us) is still here, but in varying states of disrepair. However, no weathering will have taken place in transit. The atmosphere comes out of it's frozen state on the surface, lighter elements first, coming eventually to the rather life-friendly mix that we enjoy, with some small changes. We lose a lot in terms of Hydrogen and Helium, but heavier 'metallic' gases, like oxygen and nitrogen stay put. The oceans thaw, and then partial polar caps. Assuming that the orbit time and distance are roughly similar, and the axial tilt doesn't change too much (that might be a little much to hope for), you get ruined buildings, some of which might still be habitable.

The deep freeze would be gradual, and so too the thaw. So although unlikely, some of the stonework might survive, and Terra comes out looking like Fallout meets the Jurassic/Triassic in terms of geology and geography. The midwest is a huge inland sea, and Florida and Massachusetts are all underwater. Oh, and Manhattan island.

The problem you run into is orbital eccentricity. Terra's current orbit is very nearly completely round, with very little variation. A capture orbit would look like Pluto's, with a wide range of eccentricity. Assuming for a moment that Terra's new orbit keeps her away from the natives to the system, eventually she would return to a more or less round orbit, but that action would be extremely slow. Sir Issac won't let it happen any other way. Without artificial assistance, the planet would be Damned Cold for a significant portion of it's year. Something to think about.

[Spiky Caterpillar]

The easiest way to fling the Earth out of the sun's orbit naturally and in
one piece is probably a close pass by a wandering superjovian or brown dwarf
perturbing our orbit (or Jupiter's orbit) sufficiently that future interactions
wind up flinging Earth out.

(The helium flash might knock Earth out of the solar system, but as an
iron-rich section of plasma rather than an intact planet; a sufficiently
forceful impact would go THROUGH the planet, leaving a giant cloud of
congealing magma to resolidify in roughly its current orbit.)

In that case, for the first few orbits we have a period of significant climate
instability - as we head out past the orbital radius of Mars, the water
snows out of the atmosphere and a thin crust of ice forms over the oceans.
We'll probably be most of the way to the main asteroid belt by the time the
CO2 snows begin, but the bottom of the oceans remains liquid. Surface life
huddles around volcanic oases, and, if mid-twentieth century technology is
retained, nuclear reactors. The chemoautotrophes and radioautotrophs of the
upper few miles of the crust do not notice.

As perihelion approaches, the carbon dioxide boils off, and portions of the
water icesheet may even melt, only to freeze over again as winter returns.

When the Earth is finally flung into the outer darkness, the final rain
will begin - the first nitrogen raindrops boiling as they touch the ice
beneath, but their boiling will cool the icesheet and the next drops will
flow down - clear rivulets flowing and boiling and flowing again under a
sky full of stars, then finally freezing solid.

Below, the oceans too will slowly freeze, eventually isolating the volcanic
vents in tiny pockets. I wonder what effect this will have on continental
drift - I suspect that it will probably shut it down, and in ten or a hundred
megayears stressed internal convection will burst forth in a paroxysm of
vulcanism - a brief rebirth of life basking in the fire of cooling magma,
and then the freeze returns. A further turning, and another, and then the
world is made of ice.

Here and there, pockets of life persist - things that live within rocks and
feed on traces of radioactivity in the few places where it is warm enough
for whatever solvents have displaced water in their biology to remain liquid.

Perhaps a strange form of life will emerge from the icesheets to cast sensory
organs towards the sky. Perhaps they shall even understand what it means
when the nitrogen stones of which they built their towers begin to crumble
in the heat from outside.

Perhaps they will be able to adapt themselves, create a form of artificial
life capable of surviving the nightmarish conditions that their scientists
predict will happen if the world is captured by a star. Perhaps they will
flee, gossamer spaceships rising on plumes of balefire into the starspecked
sky, seeking habitable worlds on the outskirts of the titan that will ruin
their home. Perhaps they end in futile prayer, or begin too late the
construction of the vast engines that would divert their world's path.

Perhaps they never were, and only parabacterial spores remain, to boil away
when the ground becomes the sky.

Entering orbit, first the nitrogen and oxygen will boil, then the carbon
dioxide will follow and the oceans will begin to melt. Depending on how
close you are to the new host star, this may introduce a new risk - if the
host star's position is significantly hotter than Earth's, atmospheric
water vapor may be disassociated and hydrogen lost, shifting the world
towards a thicker, denser atmosphere than what we are used to - more like
a cold Venus than a hot Earth, with the lower atmosphere teeming with
the flying polypous descendants of the cold ones' artificial life, though
I'm not sure where exactly the temperature tipping point between Earthlike
and Venuslike environments is. If still an oxygen/nitrogen atmosphere, at
150F you're likely looking at very high humidity.

Also, have two horribly-drawn pictures of alien planets orbiting a small
red star and a blue giant, respectively.

Orbiting a red dwarf in a hot orbit would require a very short year and quite likely lead to tidal locking; orbital eccentrity could well be a more important season determiner than axial tilt. Orbits around a big hot blue star will be long and slow, with seasons that will last for decades at a minimum, and axial tilt or lack thereof will matter a great deal more.

(Technical Flaws: The red dwarf is probably drawn too small; the blue giant is
drawn too big because a pinprick of blinding light is a bit hard to draw
without access to colours brighter than white.)

[Taleweaver]

Aside from being significantly hotter, a 65-degrees-centigrade Earth would very probably also be a lot more humid, pretty much the "cold Venus" idea that Spiky Caterpillar mentioned. It would be constantly shrouded by clouds, and if its orbit is a little eccentric, also wracked by tropical storms during each change of the seasons that outshadow anything we know today because of the enormous amount of energy involved. If the planet's rotation is significantly slower than that of Earth and days exceed 50 hours, the temperature difference between the day and night sides might even be enough to account for a neverending tornado that wanders the surface; definitely not the sort of weather I would want to live in.

In an environment like that, intelligent life is most probable to develop underwater, though the rough situation on the surface and the need for living things to protect themselves could be a strong evolutionary marker for creative thinking and further the quick development of a brain that can do problem-oriented thinking.

[Crocosquirrel]

Actually, without Luna, Terra's rotation would speed up immensely, and our day would go from 24 hours to about 3.

[Gear]

*writes furiously*

Okay, I think I'm following...I think.

*need to keep digesting all this*

[curry nochi rice]

a desert... and no
Antarctica..

[Crocosquirrel]

Antarctica would still be present, just the land under the icy sheet, rather than the icy sheet itself.

Geography will depend more on how long it takes vulcanism to go bye-bye.