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Why We Need to Get Off the Planet

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susiebk:

For this and a lot of other good reasons ... asteroid impact (not a matter of if, but when), natural and man-made disasters, overpopulation, to utilize the abundant resources available in space, and just to find out what's out there (a la Star Trek), just to name a few.  Yes, we need to try to conserve our resources, but they are still finite and always will be, while population growth is, well, growing and growing and growing.

http://www.space.com/scienceastronomy/080226-vaporized-earth.html

Earth's Final Sunset Predicted

By Clara Moskowitz
Staff Writer
posted: 2008 February 26
07:00 am ET
 

"Some say the world will end in fire, Some say in ice," wrote the poet Robert Frost. Astronomers, it turns out, are in the former camp.

A new calculation predicts that Earth will be swallowed up by the sun in 7.6 billion years, capping off a longstanding debate over whether the sun's gravitational pull will have weakened enough for Earth to escape final destruction or not.

Other theorists have predicted that our planet will fry as the sun expands in its old age. But the time estimates have varied by a couple billion years.

"Although people have looked at these problems before, we would claim this is the best attempt that's been made to date, and probably the most reliable," said astronomer Robert Smith, emeritus reader at the U.K.'s University of Sussex, who made the new calculations with astronomer Klaus-Peter Schroeder of the University of Guanajuato in Mexico. "What we've done is to refine existing models and to put the best calculations we can at each point in the model."

If 7.6 billion years doesn't sound like an urgent death sentence, don't relax yet. Regardless of whether Earth will ultimately be vaporized, as the sun heats up, our planet will become too hot to live on before then.

"After a billion years or so you've got an Earth with no atmosphere, no water and a surface temperature of hundreds of degrees, way above the boiling point of water," Smith told SPACE.com. "The Earth will become dry basically. It will become completely impossible for life of any kind to exist. It's a pretty gloomy forecast."

Nonetheless, scientists are curious about the ultimate fate of our planet after we are gone (like all previous hominids and more than 99 percent of all species that have lived on Earth, humans will probably go extinct, and it will likely happen sooner than a billion years).

Smith's earlier studies found that Earth would narrowly escape being engorged. As the sun ages and expands into a red giant star, it will shed its outer gaseous layers, thus losing mass and weakening its gravitational pull. Previous calculations found that this let-up would allow the Earth's orbit to shift outward, enabling the planet to slip free of the smoldering sun.

But this scenario doesn't account for tidal forces, and the drag of the sun's outer layers. As the Earth orbits the sun, its smaller gravitational pull isn't completely negligible — it actually causes the side of the sun closest to our planet to hoard more mass and bulge out toward us.

"Just as the Earth is pulling on the sun's bulge, it's pulling on the Earth, and that causes the Earth to slow in its orbit," Smith said. "It will spiral back and finally end up inside the sun."

In addition, the gas that the sun expels will also drag Earth inward toward its demise.

Smith's previous calculations had ignored these effects.

"We didn't think it mattered, but it turns out it does," he said. "You might say our previous models had a gap."

There may even be hope for Earth. Some scientists have proposed a scheme for down the road to use the gravity of a passing asteroid to budge Earth out of the way of the sun toward cooler territory, assuming there is life around at the time that is intelligent enough to engineer this solution.

"It sounds like science fiction, but there's a group of people who have quite seriously suggested that it might be possible," Smith said. "If it's done right, that would just keep the Earth moving fast enough to keep it out of harm's way. Maybe life could go on for as much as 7 billion years."

Smith's findings have been accepted for publication in the journal Monthly Notices of the Royal Astronomical Society.



And the Robert Frost poem, "Fire and Ice", for good measure.  I have always liked it.

SOME say the world will end in fire, 
Some say in ice. 
From what I’ve tasted of desire 
I hold with those who favor fire. 
But if it had to perish twice,
I think I know enough of hate 
To know that for destruction ice 
Is also great 
And would suffice.

brokeplex:
I've long been an advocate of "humankind not putting all of our eggs in one basket". At every Sci-Fi convention I attend there are always booths devoted to extra-terrestrial colonization and I always stop and discuss this issue. At a minimum a base on the moon could provide raw materials for low gravity manufacturing, also as a stop for space tourists. and that is a start.

But in order to really move masses of people (millions) off Earth, an earth-like planet suitable for colonization must be found. so far, no luck. we can move thousands to orbital stations in NEO or to the Lagrange points, we can establish a base on the moon and perhaps a station on Mars. But, we will need that "Star Trek" type friendly alien planet in another stellar system to really get a move on colonization.

delalluvia:
Heh, yes the earth will be gone in 7.6 billion years.  But from watching the series "The Universe", it seems the entire universe will be gone in like another dozen billion years after that.  It's a matter of you can run, but you can't hide.  ;D

I think we'll come up with something in a billion years, or we'll be long extinct because as a species, humans are too stupid to put out a fire in our own home.   :-\

brokeplex:

--- Quote from: susiebk on February 29, 2008, 03:02:43 pm ---Ooh, another sci fi nerd.  I am one too  :)  Are you familiar with the X Prize Foundation and what it is trying to accomplish?  If not, look it up:  http://www.xprize.org/.  You won't be disappointed.  The founder also founded the International Space University and his greatest goal is the colonization of space.  Separately, I know someone starting a business to mine minerals from asteroids (no joke)  The moon is also the perfect fueling station for any space venture.  Regarding space tourism, I could address this at length, but suffice to say, there is no better "cargo" than people to bring about enough space flights to reduce launch costs sufficiently to make space exploration cost effective.

There are many people working on this issue.  New planets are being found all the time, and surely some will turn out to be habitable, or at least terraformable (is that a word?  :))



--- End quote ---

all true!  and I am delighted to see you also have an interest in Sci-fi! yes,  new planets are being found in distant star systems on almost a weekly basis now. but the problem remains, a propulsion system that allows humans to journey there in a reasonable amount of time. a life time just won't do it. and I'm not so sure about cryogenesis, I don't wish to be frozen and thawed out, and doubt the efficacy of that process anyway.

except for the nearer stellar systems : centauri, epsilon eridani, etc, until we develop a "warp" FTL capability, we are pretty much stranded in the immediate area.

injest:

--- Quote from: susiebk on February 29, 2008, 09:22:21 pm ---Yes, I agree about cryogenesis.  We know how to freeze, but not how to thaw, and that is a pretty big issue.  So the possible solutions for the moment are either to significantly extend the human life span (which is possible in the near term using nanobots and other technologies, but then the overpopulation problem will only be compounded) or to use multi-generational ships, a tough sell.  Warp propulsion would be pretty helpful, but I don't think it's on the near horizon.  So I agree, finding a habitable planet close to Earth is the best goal for the moment.  Too bad space exploration has taken a backseat in US policy for so long.  We could be so much further along this path.




--- End quote ---

here is what you do....take it out of the freezer and put it in the frig a day or two before you need it....

or just stick it under some cold running water...

 ;D ;D

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