Quote:
Originally Posted by troutman
I heard a scientist on BBC explain last night that plate tectonics was very important in the rise of life on earth. Active geology is required for volcanism and atmospheres? Nutrient exchange?
Something to do with some crusts not having the right materials for plates after the meteor bombardment phase of planetary evolution.
http://theconversation.com/plate-tec...on-earth-44571 |
I've personally been musing this very thing - I've heard that active geology may be important to the evolution of multicellular life on earth, and I wonder if this is something that can only happen on larger planets - we do not see it on Mars, or on Venus, or any other planetary or other body in our solar system. Perhaps these super earths are more likely to have plate tectonics than smaller bodies?
And what about plate tectonics on a larger than earth sized body? Is there theoretically different layers that could form when a planet has a larger radius and a greater gravity? Is there some differentiation that might arise in a larger planet that might prevent the Iron and Nickel and other heavy elements from reaching the surface or staying on the surface, as often as it does on Earth? We have only one planet to look at with Plate Tectonics, perhaps we are an anomaly?
But that brings up another weird thought - how much harder would it be for a sentient species to leave one of these planets? It's hard enough at 1g to leave earth, what about at 1.4g? How much extra fuel would it take to exit the planet with 1.4g? How much more expensive would that get?
And then there is the species size. Humans are pretty big. If the gravity on a planet with life was increased, would that mean that life might not get as large? What if there WAS intelligent life on a planet, but it only got as large as say a house cat. Would that mean that these cat-sized aliens would have more trouble making a rocket as large as the Saturn V than a human sized species? Especially if they had increased gravity costs for building large in the first place? Plus, the rocket wouldn't be big enough to work there, either, because of the increased gravitation, so they would have to build even bigger?
And if these added costs are put out there, if the planet has no moon, perhaps then there is no reason to have a "manned" space program. No moon means no place to go, or want to go, except for the other potential planets in the system. We have seen just how expensive it is, and reluctant humans have been to go to Mars. Imagine no moon step.
Is it possible the Fermi paradox could be solved based on adding planetary size to the Goldilocks set of conditions needed for a planet? Not too big, but not too small?
/end weird science rant.