If the Earth were adrift in space ...

[CCWilson]

I just looked up that Twilight Zone episode. In it, the Earth was getting warmer, since its orbit was taking it closer the Sun. So a different premise, unfortunately.

[star2root]

I just looked up that Twilight Zone episode. In it, the Earth was getting warmer, since its orbit was taking it closer the Sun. So a different premise, unfortunately.

At the end of that episode...

The scene cuts to the apartment at night. In the inconceivably frigid darkness outside, the weather is anything but hot. The same thermometer reads -10°F, and there is a blizzard outside. Norma is bedridden with a high fever, and is accompanied by Mrs. Bronson and a doctor. She was only dreaming that the Earth was moving closer to the sun. In reality, the Earth is moving away from the sun and will eventually freeze over. Norma tells Mrs. Bronson about her nightmare, adding, "Isn't it wonderful to have darkness, and coolness?"
Mrs. Bronson replies with a sense of dread in her voice, "Yes, my dear, it's...wonderful."

This is also as I remember it.

[jenniferchristine]

Nuclear winter would be the first result of any major aberration in orbit round the sun as the Earth rebounds from the solar gravity or from the gravity of any object big enough to drag us away from stable orbit and cracks and volcanoes fire immense amounts of ash and cloud into the sky.
After 45 days, the land is frozen. Most people would die within the first 45 days. The sun would come out and for a few years the remains of humanity and a few small animals would survive at a feudal level.
The sun would diminish in intensity and the surface would cool over a period of years to squeeze the survivors towards the equator The tide would be most definitely out as the water froze to the poles and this would distort the earth and create more volcanoes - Game Over

[Tim K]

If the onset of the orbit change was sudden, then not much could be done to avert chaos, disaster, and ultimately extinction. With a decade or two of warning, it might be possible to build underground biospheres powered by nuclear and geo-exchange energy. The internal heat of the Earth and available resources + technology could maintain genetically-viable populations for millions of years.

Look at the bright side. The Earth with no bothersome Sun and Moon in the sky would be a great place to make Popsicles and practice amateur astronomy!

[CCWilson]

Tim, those are my conclusions, too - except that before long the snow and ice would be so deep that struggling to the surface with your telescope might not be worth the effort.

[star2root]

The earth's orbital speed is approximately 29.783 kilometers per second or about 0.01% the speed of light. This would mean, given the proper trajectory, if the earth left orbit it could enter the alpha-centuri system in about 43,000 years. In some of the scenarios listed above, it was mentioned that it might be possible for humanity to survive longer than that. That might make an interesting plot, earth leaves orbit arround our sun and many generations later is captured into an orbit around another star...

Barnard's Star would be about 59,630 years away.
Wolf 359 would be about 77,825 years away.
Lalande 21185 would be about 82,905 years away.
Sirirus would be about 85,828 years away.

If you use this idea, please send me a copy of your book and list me in the credits...

[CCWilson]

If slung out of its orbit by a massive celestial body, Earth would presumably be traveling down the road at a greater speed than its current one. So it could reach a nearby star sooner than your assumptions. However, it would strain credulity that its path would take it in just the right trajectory, with a velocity less than the escape velocity for the star it passes by . (Admittedly, the precipitating event is also a bit unlikely. The fiction gods do allow us to use an improbable occurence once, at the start of the story. But unless you're Charles Dickens, you have to stop there.) So tempting as it is to give those survivors a chance to establish a new civilization and save mankind from extermination, my conscience won't permit it.