Life in vacuum?

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Eris
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Post by Eris »

Zixinus wrote:There seems to be a more-or-less common error: you all assume that the creature lives on its own entirely, as opposed to living in a ecosystem that already grows plenty of life on its own.
Except, of course, the bit where I talk about apex predators and all... :wink:

That said, the reason for this is that we're speculating about life in a vacuum, clinging to asteroids. The most fundamental problem (as thermal and baric problems are avoidable) is that nutrients would be extremely scarce. Scarcity gets worse the larger the ecosystem gets, and more complex life forms are less robust to extreme conditions, of which there are no less than four in this case. (Extreme high and low temperature, zero or near-zero pressure, and dehydration.) Sure we could speculate about several different kinds of archaea, but they're still going to be largely archaea all the same. We don't speculate about complex ecosystems (by which I mean more than a bunch of monocells, perhaps of multiple species with some limited interactions) because the scenario is set up such that it's effing hard to get anything working let alone complex life.
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Zixinus
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Post by Zixinus »

That said, the reason for this is that we're speculating about life in a vacuum, clinging to asteroids.
As opposed to a moon or Mars-sized planet with an atmosphere? Or even an Earth-sized one, which atmosphere has been swept away by a powerful star's solar wind?
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Akhlut
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Post by Akhlut »

The main problems with a lack of atmosphere are solvents (something with low volatility) and electron acceptors for respiration (like oxygen).

So, all species would have to have a slow metabolism and have non-vapor electron acceptor, which would probably limit you to sulfur or phosphorus. Also, if this life utilizes DNA and other oxygen containing compounds, then your vaccuum life would need to be able to extract oxygen from non-atmospheric sources. Silicates, water (as ice, perhaps), or through metal oxides (which might work if a majority of life uses this metal to bond to the electron acceptors, as with hemoglobin).

There's also the problem of the slow, irretrievable loss of solvents (like water) through the body. After millions of years of vacuum, the planet will have lost a great deal of its original solvent that life is based on, unless through the action of volcanoes and plant life (assuming its waste products are gaseous instead of solid or liquid with extremely low volatility) a new atmosphere is generated (which is also a possibility).
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Post by Srynerson »

CaptainChewbacca wrote:I believe there was a star wars species that evolved on a planet where tidal forces were so strong that periods of the surface would go for days or even a few weeks without any atmosphere.
You're probably thinking of the Givin, a member of which appears in the cantina scene in SW:ANH: http://www.starwars.com/databank/species/givin/
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