5 ms·
Because eventually that body would have gravitational effects on our stable system and could throw everything out of whack.
by jvm___ 6y ago
Because eventually that body would have gravitational effects on our stable system and could throw everything out of whack.
- garmaine 6y agoIf it were in our solar system then it would be in a gravitationally stable arrangement--because if it weren't it would have already thrown things out of whack in the last 4.5 billion years.
- kabdib 6y agoThe solar system is actually not stable in the long term. Early planetary development was violent and chaotic, and the planets shifted around a lot more than you might think. We can't project orbits out indefinitely, either; multiple studies show that our ability to go out more than a few hundred million years are suspect and very dependent on starting conditions, which can obviously be easily perturbed by unknown bodies. Since we get star-sized approaches at Oort Cloud distances on the order of every few million years, that probably puts an upper bound on things.
- btilly 6y agoOur next such approach is https://en.wikipedia.org/wiki/Gliese_710 https://en.wikipedia.org/wiki/Gliese_710 in 1.281 million years. However the rate at which such encounters happen varies greatly. We are in an orbit bobs up and down from the galactic ecliptic with a period of roughly 60 million years. There are more encounters near the ecliptic, with very few encounters when we are above or below. We cross the ecliptic about every 30 million years, and last did so about 3 million years ago. So we are still in the dangerous period. It is not entirely a coincidence that the dinosaurs were wiped out 66 million years ago, during another relatively dangerous period.