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by Valectar 5512 days ago
This is a bit confusing, since a planet is defined as "a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighboring region of planetesimals.", the relevant part being "Orbiting a star or stellar remnant". I wouldn't think it would be possible to have a freely floating planet.
1 comments

Yawn. Yeah, if you have a deep affection for semantic pettiness, planets without stars are not possible.

This points to a problem with our definition. For most people planets are anything spherical that’s too small to be a star and doesn’t orbit another one of those spherical non-stars. That’s certainly the definition this article uses.

I’m not really sure how one could be confused by that. One might be petty about it – but confused?

You called him petty twice for adhering to definitions, but without these definitions it is difficult to speak precisely. The other part of your comment was much more constructive: perhaps our definition should be amended. Until the, no, these cannot be planets by definition. What is wrong with that?
Does the pettiness solve a problem with our communication? I would argue that it doesn't. I would be very surprised if anyone was actually confused by this or other similar articles. This is not even so much a problem with preciseness. All those articles say, in so many words, that they are talking about 'planets that don't orbit stars'. They amend the definition right there and then, problem solved.

This is a common way of describing things. Something is described in terms of something else, the properties that are different are pointed out separately. One might describe an e-book in terms of a book made of paper, pointing out, along the way, the important differences. Since e-books and books made of paper are very similar nobody would protest if, in that context (and after the explanation of the differences), the naked word 'book' would be used to refer to e-books.