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Earth's Final Sunset Predicted
by Space.com
Thanks to njwong for the link.
Reposted from:
http://www.space.com/scienceastronomy/080226-vaporized-earth.html
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.
Reposted from:
http://www.space.com/scienceastronomy/080226-vaporized-earth.html
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.
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Posted: Thursday, February 28, 2008 | PermalinkComments 1 - 45 of 45 |
Reload Comments | Back to Top | Page Numbers2. Comment #134985 by Klaatu barada nikto on February 28, 2008 at 12:27 pm
OK Noah. Build a spaceship. Fill it with 2 mosquitos, 2 aardvarks, 2 ………. AH, fuck it. Other Comments by Klaatu barada nikto
3. Comment #134988 by Quetzalcoatl on February 28, 2008 at 12:29 pm
Better start packing. Other Comments by Quetzalcoatl
4. Comment #134991 by Colwyn Abernathy on February 28, 2008 at 12:30 pm
"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."
Assuming we don't nuke it first...
http://endofourworld.ytmnd.com/
The Timmy Age 5 edition:
http://atleasttheresmoreoriginalcontentthantheotherone.ytmnd.com/
Now with intolerance!
Other Comments by Colwyn Abernathy
5. Comment #134998 by al-rawandi on February 28, 2008 at 12:33 pm
Soooo that is when Jesus is coming? Other Comments by al-rawandi
6. Comment #135005 by robotaholic on February 28, 2008 at 12:37 pm
if we survive another 100 years I will be amazed (old)lol Other Comments by robotaholic
7. Comment #135026 by Nails on February 28, 2008 at 1:10 pm
I thought we would have been wiped out by an impending collision with the andromeda galaxy by then, massively increased radiation and changes in the galaxy's gravitation etc. Other Comments by Nails
8. Comment #135039 by Shaden on February 28, 2008 at 1:20 pm
Don't worry, Jesus already predicted that the world was coming to an end. Though, he said it would happen within the lifetimes of his disciples. Mathhew 23:36, 24:34
*shrug*
Other Comments by Shaden
9. Comment #135090 by clodhopper on February 28, 2008 at 2:12 pm
Douglas showed the way:
We must build 3 enormous spacecraft right now. All the religious must go first as they will be guided by God.
All the management consultants, hair stylists, telephone cleansing operatives, network rail operatives can go next.
The rest of us will follow, later.
Other Comments by clodhopper
10. Comment #135115 by Colwyn Abernathy on February 28, 2008 at 2:44 pm
"Sorry for the Inconvenience."
:( Miss you, Doug...
Other Comments by Colwyn Abernathy
11. Comment #135121 by Driver on February 28, 2008 at 2:49 pm
Don Koenig calculated the statistical probability of when Jesus would return. Quite fascinating and somewhat comical:
http://www.thepropheticyears.com/comments/countdown_to_second_coming.htm
His conclusion: Between 2028 AD and 2057 AD. So no need to worry about the end of the earth.
Other Comments by Driver
12. Comment #135130 by Agrajag on February 28, 2008 at 3:00 pm
After a final pause, Marvin gathered his strength for the last stretch. He read the "e", the "n", the "c" and at last the final "e", and staggered back into their arms. "I think," he murmured at last, from deep within his corroding rattling thorax, "I feel good about it." The lights went out in his eyes for absolutely the very last time ever. Luckily, there was a stall nearby where you could rent scooters from guys with green wings.
- Douglas Adams
God's final message to his creation:
"We apologize for the inconvenience"
AJ
Other Comments by Agrajag
13. Comment #135136 by Richard Morgan on February 28, 2008 at 3:08 pm
Is this all about the film or the video game?7.6 billion years? Hang on while I note it in my Palm Planner...er, ...
Other Comments by Richard Morgan
14. Comment #135156 by SPS on February 28, 2008 at 3:38 pm
I am totally moving in a billion years.Other Comments by SPS
15. Comment #135160 by StephenP on February 28, 2008 at 3:47 pm
Unless the Vogons get here first!Hmmmm! That reminds me, has anyone checked the planning office at Alpha Centauri recently, I've been meaning to, but, there's a pile of washing that's not going to do itself...
Other Comments by StephenP
16. Comment #135166 by Jiten on February 28, 2008 at 4:05 pm
Better get in my trip to Cuba that I've always promised myself between now and then! Other Comments by Jiten
17. Comment #135178 by paulcaira on February 28, 2008 at 4:41 pm
Even if humans don't "go extinct", surely the odds are that nothing resembling them will exist in a billion years time?It's hard to help the feeling that humans are an unstable species, but if they survive, they will surely transmute into something very different. Probably back to some kind of cave-dweller?
Other Comments by paulcaira
18. Comment #135179 by js5535 on February 28, 2008 at 4:44 pm
Sic transit gloria mundi. Other Comments by js5535
19. Comment #135184 by ianmkz on February 28, 2008 at 4:55 pm
Earth's Final Sunset Predicted
Can the term sunset really be applied to the Earth? It may be sunset in Hawaii, but it's never sunset on the Earth.
Other Comments by ianmkz
20. Comment #135193 by Geoff on February 28, 2008 at 5:13 pm
I really want to say "Don't Panic!", but I'll resist the temptation. Other Comments by Geoff
21. Comment #135197 by SPS on February 28, 2008 at 5:19 pm
So long, and thanks for all the fish.Other Comments by SPS
22. Comment #135205 by LorienRyan on February 28, 2008 at 5:45 pm
Goodbye sweet world, will miss you... hold on... 7.6 billion years, lets party! Other Comments by LorienRyan
23. Comment #135209 by steveroot on February 28, 2008 at 5:50 pm
19. Comment #135184 by ianmkz on February 28, 2008 at 4:55 pm
Earth's Final Sunset Predicted
Can the term sunset really be applied to the Earth? It may be sunset in Hawaii, but it's never sunset on the Earth.
When the *sunset* on the earth, it smash that sucker flat! ;-)
Ste5e
Other Comments by steveroot
24. Comment #135249 by Slyer on February 28, 2008 at 6:48 pm
Oh, phew, I thought it said 7.6 million! What a relief. Other Comments by Slyer
25. Comment #135253 by Steve Zara on February 28, 2008 at 6:55 pm
We have a lot more to worry about before then. The increasing temperature of the sun means that the Earth will dry out in a billion years or two, and then a few billion years after that, the Andromeda galaxy is going to collide with ours... Other Comments by Steve Zara
26. Comment #135254 by Goldy on February 28, 2008 at 6:56 pm
We have a lot more to worry about before then
Dammit! What am I going to do with this bulk order of sunscreen from the Auckland Cancer Society then? ;-)
Other Comments by Goldy
27. Comment #135256 by Steve Zara on February 28, 2008 at 7:01 pm
Comment #135254 by Goldy Dammit! What am I going to do with this bulk order of sunscreen from the Auckland Cancer Society then? ;-)
Ship it to Titan, the moon of Saturn.
As the sun warms up and eventually expands, Titan will become pretty Earth-like. It should be habitable just before Andromeda hits, and the solar system is sent on a wild ride either into inter-galactic space, or towards the central black hole of the galaxy.
Other Comments by Steve Zara
28. Comment #135258 by LorienRyan on February 28, 2008 at 7:01 pm
Steve,
I will be making sure I pull my doona cover over my head at night now.
Maybe they should start the Andromeda 'duck 'n' cover' campaign soon.
Other Comments by LorienRyan
29. Comment #135262 by Goldy on February 28, 2008 at 7:05 pm
Ship it to Titan, the moon of Saturn.
Hmmm, good idea. Good job you're around! Now, where's that intergalactic mover's number and what are their domestic prices...
Other Comments by Goldy
30. Comment #135292 by AshtonBlack on February 28, 2008 at 7:31 pm
7.6 billion huh?I might of saved up enough money to afford the deposit on a new house in the south of England by then... Mind you I suppose that house prices might have come down a touch, what with all the atmosphere burning off and that.
Other Comments by AshtonBlack
31. Comment #135323 by JanChan on February 28, 2008 at 8:38 pm
Isn't the Milky Way going to crash into another galaxy in 3 billion years? I think I would be more worried about that, rather than the dying sun.Other Comments by JanChan
32. Comment #135335 by Steve Zara on February 28, 2008 at 8:55 pm
Comment #135323 by JanChanIsn't the Milky Way going to crash into another galaxy in 3 billion years?
Probably about 5 billion, but yes.
It really isn't anything much to worry about. Stars almost never collide, just perterb each other's orbits within galaxies.
The problem could be comets. There is a vast cloud of comets around the sun, stretching a lot of the way towards Alpha Centauri.
Any stars coming close tends to disturb them, and send some of them towards us.
Other Comments by Steve Zara
33. Comment #135341 by Garic on February 28, 2008 at 9:05 pm
Hmm, Titan sounds nice. I hear they have methane rain... and lakes Other Comments by Garic
34. Comment #135361 by Ian H Spedding FCD on February 28, 2008 at 9:41 pm
Steve Zara wrote:As the sun warms up and eventually expands, Titan will become pretty Earth-like. It should be habitable just before Andromeda hits, and the solar system is sent on a wild ride either into inter-galactic space, or towards the central black hole of the galaxy.
Didn't Lawrence Krauss just co-author a paper arguing that black holes can't exist?
Other Comments by Ian H Spedding FCD
35. Comment #135362 by Steve Zara on February 28, 2008 at 9:44 pm
Comment #135361 by Ian H Spedding FCD Didn't Lawrence Krauss just co-author a paper arguing that black holes can't exist?
Yes, he did. I should have put "black hole" in ironic quotes. Perhaps "region of worryingly strong gravitational field" would have been more appropriate.
Other Comments by Steve Zara
36. Comment #135365 by Dr Nev on February 28, 2008 at 9:51 pm
Bugger! Round about this period of time religion will finally be eradicated and we will all be living in harmony and then we melt! Gee! Other Comments by Dr Nev
37. Comment #135455 by Ygern on February 29, 2008 at 1:59 am
I was reading only yesterday that the molten core of the earth would probably have cooled completely within four and a half billion years (ie long before the sun is expected to go nova), which would leave the planet pretty lilfeless too. This would pre-empt any plans to do any planet-moving, surely?Or is that theory disputed?
Other Comments by Ygern
38. Comment #135469 by clodhopper on February 29, 2008 at 2:25 am
Please can all this badness happen AFTER I've been to the Jethro Tull concert at the Lowry in April? Thanks. Other Comments by clodhopper
39. Comment #135472 by Dr Nev on February 29, 2008 at 2:34 am
RE: Comment #135455 by Ygern: Regarding the Earth's core cooling around four and a half billion years - I'd love to read about this, sounds fascinating! Where did you read this, I'd love to read the article.
Other Comments by Dr Nev
40. Comment #135488 by Ygern on February 29, 2008 at 3:12 am
Dr NevHere's the link.
http://csmres.jmu.edu/geollab/fichter/PlateTect/heathistory.html
I'm no scientist, so I don't know how accurate or accepted etc the article is.
Other Comments by Ygern
41. Comment #135521 by bluebird on February 29, 2008 at 4:03 am
Interesting article/comments...plenty to ponder.
I heard about this "scheme" the other day; it does sound like science fiction.
Anyway, Happy Leap Day!!
http://antwrp.gsfc.nasa.gov/apod/ap080229.html
Other Comments by bluebird
42. Comment #135604 by rod-the-farmer on February 29, 2008 at 6:14 am
the sun's gravitational pull will have weakened enough for Earth to escape final destruction
????? Pardon my lack of an advanced astrophysics degree, but how the HE!! will that transpire ? Where would all the mass go that creates the current gravitational pull of the sun ? Oh, later it says that some of the outer layers will blow off, thereby reducing the total mass of the sun. The exact percentage, the volume/mass involved etc. were not provided. Enough to reduce solar attraction that would allow the earth to escape, like cutting the string on a weight whirled around your head. I guess our "shields up" technology will be working by then, deflecting this enormous mass of the solar atmosphere from scouring the planet clean of all life. My un-educated guess is that the pressure of the blown-off solar atmosphere will push earth quite easily out of its' current orbit. And as for the pull of the earth causing a tidal bulge in the sun, geez louise, given the distance combined with the relative masses - I ha' me doots.
Other Comments by rod-the-farmer
43. Comment #135721 by passutoba on February 29, 2008 at 8:31 am
Loved this article.....really interesting and, whatever the means towards the inevitable outcome, it should make us realise just how irrelevant we are in the bigger picture. Nutters take note.it seems to me, eminently unqualified on the issue, that the idea of the earth escaping from the Sun's fiery grasp may be a reflection of human arrogance about the 'special' nature of our planet. The futile wish for our pale blue dot to somehow be able to avoid its fate. I guess planets are coming and going all the time.
Other Comments by passutoba
44. Comment #136209 by Saerain on February 29, 2008 at 2:19 pm
36. Comment #135365 by Dr Nev on February 28, 2008 at 9:51 pmShit, maybe that is what the Christians mean, without realising it. If we reject God, we burn into extinction. If we accept God, we die in war or disease much sooner.
Bugger! Round about this period of time religion will finally be eradicated and we will all be living in harmony and then we melt! Gee!
Other Comments by Saerain
45. Comment #136676 by Laurie Fraser on March 1, 2008 at 2:47 pm
Makes the sub-prime crash look slightly insignificant. Other Comments by Laurie Fraser
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1. Comment #134977 by Colwyn Abernathy on February 28, 2008 at 12:22 pm
Epic...world ending maneuver?
Other Comments by Colwyn Abernathy