(October 6, 2019 at 11:42 am)Gawdzilla Sama Wrote: Hydrogen and oxygen are the two most common elements in the Universe. This means water is very common. VERY COMMON.
Yes, and what is more, water is more abundant in outer reaches of planetary systems, because when the parent star went through its t-Tauri stage early in its life, it blasted much of the water out of the inner parts of the planetary system before inner planets can form. So there are a lot more water out there than in here.
More over, wet planets like earth, which exist close to their parent stars and thus deep down inside the gravity well of the sun, is hardly the economic place to mine water if your intention is to take it to a different star system. You have to spend all the energy to push the water back up sun’s gravitational gradient. Energy wise. It would be far more economically to get water from bodies in distant parts of solar system, where they would be much more loosely bound by sun’s gravity and thus easily detached from the sun’s gravity.
Overall, the notion that alien conquest of inner habitable planets would be driven by resource acquisition just does not make much sense. There is no real natural resource available on earth that can’t be obtained in other parts of solar system where they would be easier to transport back to another stellar system. If aliens were to come and visit in enormous spaceships, it also makes little sense to bring the enormous spaceship all the way into inner solar system and park them over the earth. Again, it would take enormous amounts of energy to shed their interplanetary speed just so they can slide down the sun’s gravity well, and when they are ready to leave, burn enormous amounts of energy to climb back up the sun’s gravity well.
