Should "speeding up the rotation of a planet" be closed?

Question

When the question How would one go about speeding up the rotation of a planet? was posted, four close votes were added citing that the question was off-topic here, but on-topic on Physics.SE where it already has an answer. Since then, one of those close votes has been removed.

Hash linked this question from Physics.SE which is about speeding up the rotation of Venus with the restriction that the speeding up must be done with weather manipulation.

Rory Alsop replied:

That's a good point @Hash - it works over there on Physics, but is a tad offtopic for space exploration.

And also:

This question is on-topic on Physics.SE, where it has already been answered

Don Branson said:

@RoryAlsop - Can you provide a link to the answer? [the Venus article on Physics.SE] doesn't answer this particular question.

After this Rory and Don talked some more and eventually came to agree that it was already answered. You can see the conversation on the original question.

Apparently though, there is not full agreement over two matters:

1) Is the question on-topic on Space Exploration?

2) Has the question already been answered on the linked Physics.SE question?

I've posted this question because I am not entirely convinced in either direction.

To me, at first glance, the question looks ok for our site because it is about terraforming. But I noticed that if you remove the word terraforming it looks like a physics question. The word terraforming really adds nothing to the way the question will be answered.

So maybe it is a Physics.SE question.

However, I am not entirely satisfied that the question that is over at Physics.SE satisfactorally answers this question. The question at Physics.SE is about Venus particularly, while this question is about any planet (or even asteroid). Maybe that makes it too broad, but I don't know. PearsonArtPhoto's answer, while it uses the word Venus, seems more widely applicable. It seems that the question can be answered in a broad sense, and maybe it should.

Should we migrate the question to Physics.SE where it can be answered? Or should we close it because it has already been answered?

Answer 1

Point 1: Terraforming should be on topic here, so long as it's kept realistic. There have been many questions on the subject, and there doesn't seem to be a good reason to ban them.

Point 2: I'm not sure if I care. I've started a post on MSO asking about this question, what to do about unintentional cross posting, hopefully the community there will come up with an answer. Even giving that, I would say that it is not an exact duplicate. Bottom line is, it is my belief that we should ask questions on this site which we think are on topic here, and not worry about if the question has been asked/answered elsewhere. Linking to another SE post is okay, in the same way that linking to wikipedia is okay.