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Space Science

Vega Older Than Thought: Mature Enough To Nurture Life 130

sciencehabit writes about new estimates of Vega's age giving hope that any planets it might have are old enough to harbor life. From the article: "Shining just 25 light-years from Earth in the constellation Lyra, Vega is the fifth brightest star in the night sky. In 1983, astronomers discovered dust orbiting the star, suggesting it had a solar system, and Carl Sagan chose to make Vega the source of a SETI signal in his 1985 novel Contact. At the time, Vega was thought to be only about a couple hundred million years old, probably too young for any planets to have spawned life. Since then, however, estimates of Vega's age have increased to between 625 million and 850 million years old. So suitable planets have probably had sufficient time to develop primitive life." With improvements in telescopes allowing detection of the rough atmospheric composition of exoplanets on the way, this could be pretty exciting.
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Vega Older Than Thought: Mature Enough To Nurture Life

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  • by Daetrin ( 576516 ) on Monday December 03, 2012 @10:00PM (#42175337)
    So to follow up, according to wikipedia [] (yes, i'm breaking all the rules by using it as my primary source) the earliest possible signs of life on earth found so far are from 3.8 billion years ago, 700 million years after the earth formed, but there are other processes that could account for those signs. The earliest "undisputed" signs of life are from 3 billion years ago, 1.5 billion years after the earth formed. And more importantly life didn't start significantly altering the atmosphere until 2.4 billion years ago []. At least i'm not aware of any significant effects until the production of oxygen started.

    So it's just barely possible that life might have started on the theoretical Vega planets, if we assume the earliest possible date for life on earth and assume that life on those planets follows a very similar path. (We only have one data point so far, so everything is an assumption.) But even if that's the case, we won't be able to detect that life using atmospheric analysis like the blurb says because, again assuming they follow the same timeline, they won't be evolved enough to have done anything to the atmosphere yet.

    If there's something obvious i'm missing, please let me know.
  • by Daetrin ( 576516 ) on Monday December 03, 2012 @10:36PM (#42175569)
    Hmmm, interesting theory, but only if we're speculating about a form of life totally different from the kind of life on earth. If we're talking about the kind of carbon based life that needs liquid water to survive, the planet will need to be in the Goldilocks zone [], meaning that the planet will intercept about as much energy per square meter as the earth does. i.e. the hotter the star, the farther out the planet will be.

    As soon as we throw out the idea of carbon-based life forms that need liquid water we really have no idea what kind of habitat they'd need or how quickly they'd evolve and it's all just a guessing game.
  • by VortexCortex ( 1117377 ) <.moc.edargorter- ... . .xetroCxetroV.> on Monday December 03, 2012 @11:42PM (#42175919)

    It boggles the mind that from this one sample scientists think they know when, how, and where life can and can't form in the universe.

    It's elementary my dear Watson... That is to say, it's all about the elements we see, and their known properties, and energy levels at which reactions occur. Sure there may be outliers somewhere but they, by definition, are pretty far out there.

    Turns out that binary star systems are a lot more common than we once thought. In a binary star system, when a white dwarf eats another yellow star it starts producing lithium, and other heavier elements -- When it gets up to iron, it's game over. BLAM Type 1-A supernova. That's the most common supernova there is, and one of these is likely responsible for making all the elements floating around our sun. Furthermore, our sun seems to be pretty damn average. Additionally, rocky iron core planets are probably pretty damn common too. When you think of it like that, that tons of similar ovens are baking the same ingredients at around the same temperatures, then it's less of trying to find life exactly like our own, and more of looking for signs of the chemistry we know happens in a very common type of life baking oven -- Indeed, the kind that produced us. Our planet's not some really off the wall special place, so we're not special either. A puddle might think that its hole was perfectly designed just for it to fit in, but the reality is you make a divot, add water, you got a puddle... If we were looking for puddles we'd try to locate places where the temps are right to have liquid water. It's the same sort of thing for finding life.

    That doesn't mean that there's no metal based life with mercury for blood and live the most brutal places, but it's a hell of a lot more likely that it'll be Carbon, Hydrogen and Oxygen that run alien life. Also, when you ( bake / cool / repeat ) the basic ingredients plentifully found on our planet eventually you discover amino acids form. The first self replicating chain of which will quickly dominate the other randomly joined chains by tearing them up to make copies -- a few imperfect copies, and you've got competition and evolution. Hell, the exact same thing happens in my automata experiments where little dots can randomly attract or repel -- Run the sim for a few months and you get some forming chains, then replication, and competition and evolution -- "Life" starts happening in my RAM. The parameters for the attraction and repulsion and boding co-efficients have to be right or nothing happens though... It's chemistry 101. There's no reason to remain boggled at all; Read up.

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