Recent comments in /f/space

Dahnlor t1_j5716jp wrote

Reply to comment by rickny0 in Will Pluto ever be a planet? by twurbster

Nitpick: Ceres is in the Asteroid Belt and was discovered in 1801. Its discovery was not unlike that of Pluto, and it was considered to be a planet until after several other asteroids were discovered.

Pluto's discovery and eventual recategorization was pretty much the same situation, except that every new Kuiper Belt Object wasn't being counted as another new planet. When Eris was discovered, which is larger than Pluto, it forced the IAU's hand in creating an actual definition for "planet".

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GodzlIIa t1_j570lr5 wrote

Reply to comment by rba22 in Will Pluto ever be a planet? by twurbster

Thats the difference between "would it ever be recognized as a planet again" vs "will it ever be a planet again". It was NEVER a planet based on current definitions, but it was called a planet in the past.

Is OP asking if definitions might change calling it a planet, or is op asking will it somehow fit current definitions in the future.

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space-ModTeam t1_j570lod wrote

Hello u/twurbster, your submission "Will Pluto ever be a planet?" has been removed from r/space because:

  • Such questions should be asked in the "All space questions" thread stickied at the top of the sub.

Please read the rules in the sidebar and check r/space for duplicate submissions before posting. If you have any questions about this removal please message the r/space moderators. Thank you.

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GiraffeWithATophat t1_j5702dw wrote

If we ever change our technical definition of a "planet" then it could be recognized as one again.

Regarding your second edit, you can kind of think of it that way. The moon orbits the earth like pluto orbits the sun. However for it to be called a "moon" the object needs to be orbiting something other than a star.

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rickny0 t1_j56y7nr wrote

Reply to comment by rosen380 in Will Pluto ever be a planet? by twurbster

IMO Pluto lost its status because astronomers kept discovering more Pluto-sized objects orbiting the sun and they didn’t want to add a bunch of new planets. (Eris · Ceres · Haumea · Makemake)

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rosen380 t1_j56xlnc wrote

That isn't part of the reason it was "downgraded" to dwarf planet though... per the IAU these are the requirements:

  1. It is in orbit around the Sun.
  2. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape).
  3. It has “cleared the neighborhood” around its orbit.

Pluto meets the first two, just not the third.

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