Skip to comments.Real Doomsday: Earth Dead in 2.8 Billion Years
Posted on 07/02/2013 7:42:10 PM PDT by DogByte6RER
Real Doomsday: Earth Dead in 2.8 Billion Years
The Rolling Stones Mick Jaggar crooned Time Is On My Side in the 1964 classic rock hit of the same title. Sadly, thats not the case for habitable planets orbiting sun-like stars according to a recent computer simulation by astrobiologist Jack OMalley-James of the University of St Andrews in the United Kingdom.
A combination of slow and rapid environmental changes will result in the extinction of all species on Earth, with the last inhabitants disappearing within 2.8 billion years from now, OMalley-James predicts.
He says that weve got about 2 billion years left before the oceans will have evaporated leaving behind a desiccated sand dune landscape as alien-looking as that of Mars. The last vestiges of life on Earth will have retreated to the few scattered reservoirs of water left on our planet.
As is well-known from stellar evolution theory the sun will remain stable over the next few billion years but become steadily brighter as fusion reactions in the core change.
His modeling shows that within the next billion years, increased evaporation rates and future chemical reactions with rainwater will draw more and more carbon dioxide from the Earths atmosphere. The falling levels of carbon dioxide will lead to the extinction of plants and animals and Earth will become a world of microbes. At the same time, the Earth will be depleted of oxygen and will be drying out as the rising temperatures lead to the evaporation of the oceans.
The far-future Earth will be very hostile to life by this point. OMalley-James says. All living things require liquid water, so any remaining life will be restricted to pockets of liquid water, perhaps at cooler, higher altitudes (as with the lakes on Titan, pictured right) or in caves or underground. This life will need to cope with many extremes like high temperatures and intense ultraviolet radiation.
This gloomy forecast is sobering because there has been a lot of news about finding Earth-sized planets in the habitable zones around other stars. But whats mostly overlooked is the temporal dimension. How old are the planets? What is their stage of evolution?
Though the sun burns as a main sequence star for 10 billion years, the window of opportunity for advanced life on Earth is about 25 percent of the suns lifetime, according to this latest model.
Those exoplanets where conditions have deteriorated to where life has moved underground (such as is likely the case with Mars) have feeble or no chemical biotracers to study from light-years away. Dying Earths will have a nitrogen and carbon-dioxide atmosphere with methane being the only sign of active life, OMalley-James predicts.
Recent estimates for the number of Earth-like planets in the galaxy range from 17 to 100 billion. Lets be especially conservative and say 10 billion are Earth clones. Most of these will orbit red dwarf stars that are far more long-lived that our sun. This leaves us with 1 billion Earths orbiting solar-type stars. But roughly 250 million of these are at a stage right now where they can support complex life according to OMalley-James model.
Still, these are not bad odds for finding someone else out there in the galaxy.
I would further argue that alien civilizations orbiting a sunlike star are more likely to pursue interstellar colonization because of the comparatively short lifespan of their home star. And extraterrestrials living in binary systems (like Alpha Centauri) would further be motivated to pursue space-faring because they want to explore inhabitable planets orbiting the companion star.
Alternatively, aliens may chose to slowly move their home world into a wider orbit that backs off from a heating-up star. This requires no more science that a straightforward application of Newtonian mechanics. Newly forming stars are dynamically shuffling planets around all the time.
Therefore, the future is not so dour if we plan on either moving Earth to a cooler place in space, or leaving our home world behind to colonize another star.
“A combination of slow and rapid environmental changes will result in the extinction of all species on Earth, with the last inhabitants disappearing within 2.8 billion years from now,”
Curse you Dogbyte for posting this! I don’t know how I’m going to be able to sleep tonight!
Even worse ... despite all of this gloom and doom, we’ll STILL be stuck with Obamacare.
Cool. Now I know how far ahead I need to post-date my checks.
It’s rumored he’ll be appearing in the “Man of Steel” sequel.
In 2.8 billion years evidence of man’s ephemeral existence on earth will have been molded, folded and melted into the geologic record.
“I’m prepped for the sun going red giant. I know Someone that’s got me covered.”
I am far more worried about man destroying himself, long before the sun kills us.
The reelection of Obumbo tells me that man has passed his “use before date”.
As for finding a new world to live on, one had best find those imaginary wormholes to imaginary parallel universes, or find the mythical way to exceed the speed of light.
Give me warp 10, Scotty.
By reducing our carbon emissions we are hastening the day the earth dies.
In 2 Billion Years, we’re going to be saying, “My how time flies.”
I’m sorry that I won’t be around to see the end.
Thank goodness I won't be there to see that outrage!
yep....I’ll be outta ammo by then...
I got your back!
Would love to have a time machine to witness the Hoover Dam eroding away into nothingness as well as the mushrooms on Manhattan Island.
Wow I better look fast for a hubby =)
Read Revelation Chapter 21.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.