So if you put earth into the Oort Cloud it would still be a planet, because we know that earth has the potential to clean it’s neighborhood.

Would it be a non-planet for the millions of years it would take to clear its orbit?

Does Earth’s body/features magically change somehow for the duration of the clearing process, so that it doesn’t resemble a planet?

The point is that using external criteria to identify what an internal thing is is not logical, or scientific.

The theoretical object in the Oort Cloud would relative fast clear the space around himself if it had the size to have a stable and long living internal heat source.

You don’t know that, especially with the size of the Oort Cloud, and the size of the orbit to clear. And the rules for how much clearance has to be done is very arbitrary.

Also bodies can be small and have a decaying heat source that’ll last many millions of years, or renewing heat source via tidal interactions. It’s not necessarily a size thing.

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