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Astronomers Spot Most Distant Object In the Solar System (sciencemag.org)

sciencehabit writes: Astronomers have found the most distant known object in our solar system, three times farther away than Pluto. The dwarf planet, which has been designated v774104, is between 500 and 1000 kilometers across. It will take another year before scientists pin down its orbit, but it could end up joining an emerging class of extreme solar system objects whose strange orbits point to the hypothetical influence of rogue planets or nearby stars. In other planetary science news, UCLA professor Jean-Luc Margot has proposed a new definition of the term "planet" which would allow for the inclusion of exoplanets. His metric is laid out in an academic paper available at the arXiv.

3 of 85 comments (clear)

  1. It's so ridiculously easy by Rei · · Score: 3, Insightful

    .. to make up a formula to say what you want it to say for data like this.

    Here, want an alternative formula to declare the 8 IAU "planets" as planets as well as exoplanets but exclude the IAU "dwarf planets", without using any of the terms he uses, and to be able to classify 100% (rather than the 99%) of exoplanets?

    MeanDistanceFromTheSun / DiscoveryYear ^5 > 0.21mm/y^5

    It's a functional formula. Does this mean that it's a reasonable formula? Of course not; it has no connection with the reality of what they actually are. But you know what? Neither does his or the IAU's "cleared the neighborhood" concept. There are no credible planetary models that show for example that Mars cleared its own neighborhood. While they differ on the details, they all agree that Jupiter cleared it (and cleared most of the debris from the inner solar system in general, with some help from Saturn). Neptune has (despite its distance from the sun) orders of magnitude more orbit-clearing power than Mars yet nonetheless contains multiple objects a couple percent the size of Mars in its "neighborhood". Is Mars not a "planet"?

    I have a giant list of reasons why the IAU decision is poor and unscientific, but no need to post it again.

    --
    The yellowcake is a lie.
  2. Re:Does this mean??! by Rei · · Score: 2, Insightful

    Nope. A tiny fraction of a group who is overwhelmingly not planetary scientists has spoken and made their internally-inconsistent definition. It stands until they revoke or alter it.

    --
    The yellowcake is a lie.
  3. Re: Does this mean??! by Anonymous Coward · · Score: 1, Insightful

    There are not little complaints about "the exact wording" - do I really need to go into a breakdown of all of the arguments against it?

    No, but if you are going to demand citation from others about what the majority of planetary scientists think, you can't conveniently ignore that yourself.

    Do you have any citation that the vote was not representative, and that it would have changed the status of Pluto if any of that stuff you complain about was different? And finding a few planetary scientists that are upset about the definition is not the same as saying a majority care to vote for/against it.

    It doesn't matter how quirky the voting was or not if it wouldn't have made any difference. Whatever arguments you have doesn't change how the planetary scientists or IAU at large would have voted either if you removed some of those common quirks in the vote.

    So yeah, as you said, citation needed...