|MadSci Network: Astronomy|
I have been learning about the solar system. Some astronomers think that Neptune, which is now about 4.5 billion km from the sun, used to be much closer. This got me to thinking: if Neptune hasn't always been where it is, how did it get where it is? What force could move something this massive? Recently, I have learned about how the moon causes tidal bulges in the earth, which are most noticeable to us in the oceans. Furthermore, the way the bulges rotate under the moon and tug on it in its orbit very slowly cause the moon to migrate further away- maybe just a few centimeters a year. In some ways, planets are to the sun what the moon is to earth. Could this tidal mechanism be influencing the orbits of planets too? In particular, could Neptune have migrated to its current location due to this effect? I know the effect must be tiny if it exists at all, but we've got billions of years to work with, so perhaps it adds up. Any help on this issue is greatly appreciated.
Re: Do planets cause tidal bulges in the sun?
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