Jupiter Destroyed 'Super-Earths' In Our Early Solar System
sciencehabit writes: If Jupiter and Saturn hadn't formed where they did—and at the sizes they did—as the disk of dust and gas around our sun coalesced, then our solar system would be a very different and possibly more hostile place, new research suggests (abstract). Computer models reveal that in the solar system's first 3 million years or so, gravitational interactions with Jupiter, Saturn, and the gas in the protoplanetary disk would have driven super-Earth–sized planets closer to the sun and into increasingly elliptical orbits. In such paths, a cascade of collisions would have blasted any orbs present there into ever smaller bits, which in turn would have been slowed by the interplanetary equivalent of atmospheric drag and eventually plunged into the sun. As Jupiter retreated from its closest approach to the sun, it left behind the mostly rocky remnants that later coalesced into our solar system's inner planets, including Earth.
So how come that happened in our solar system, but not in the many other exo-planetary systems that we have found recently/
Selection bias. Our planet detection technology is still very primitive. We have found lots of big, hot planets orbiting very close to stars, not because they are common, but because they are easy to detect.
So, we're looking for other civilizations, haven't found any, even though we estimate that life should be common. After all, if it happened here it should be able to happen in a lot more places.
But perhaps the set of circumstances that would create an environment that lasted long enough for life to be created and evolve to this point are wildly, vanishingly improbable. Perhaps the only reason we think it should have happened lots of other places is that we are the ones doing the looking, and we don't realize just how rare we actually are.
But that's a little depressing.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.