[GonzoGOP]

I have been saying for a long time that the way to reconcile the Drake Equation with the Fermi Paradox is that intelligent life needs truly extraordinary conditions to occur. Earth with plate tectonics, a moon way bigger than a planet this size should have, a stronger magnetic field that a planet this small should have and Jupiter to sweep up comets and asteroids is a very rare bird indeed.

However of those four factors, the first three can all be traced to a single almost unimaginably rare event. The collision between the proto earth and another planet roughly the size of mars. Two objects that large hitting should have obliterated both objects. Instead they struck a glancing blow, bounced off and then hit again at a much slower speed. The result is that we have a planetary core made from the cores of two planets. Giving us a magnetic shield to protect us from the worst solar radiation. The Earth also picked up a lot of extra heat, allowing plate tectonics, that recycles our atmosphere, to go on much longer that it would have. Finally Earth gained a big moon from the debris of that first glancing hit that slows down our rotation and provides the tidal zones where life first emerged onto the land.

[KoRn]

All very true. There’s so much more involved with our existence here than the planet being in a “Goldilocks Zone”. Take away our Moon and Plate Tectonics, and we probably wouldn’t be here, yet we’d still be in the magical “Goldilocks Zone”. I’m sure Jupiter has kept us here longer than we otherwise would have been.