Robotic Spacecraft (Astronomy, Planetary, Earth, Solar/Heliophysics) > Space Science Coverage
Dwarf planet discovery hints at a hidden Super Earth in solar system
Star One:
https://www.sciencenews.org/article/distant-planet-may-lurk-far-beyond-neptune?mode=magazine&context=189396
MP99:
ISTR that Pluto was demoted because it doesn't dominate it's orbit gravitationally (ISTR the Hill sphere came into it).
If this postulated object is "shepherding" Sedna and 2012 VP113, does that mean that it might fit within the definition of "planet" rather than "dwarf planet"?
Cheers, Martin
clongton:
--- Quote from: MP99 on 03/26/2014 06:34 pm ---ISTR that Pluto was demoted because it doesn't dominate it's orbit gravitationally (ISTR the Hill sphere came into it).
If this postulated object is "shepherding" Sedna and 2012 VP113, does that mean that it might fit within the definition of "planet" rather than "dwarf planet"?
Cheers, Martin
--- End quote ---
It's possible. For its gravitational effect to be large enough to shepherd these bodies like this it would need to be much larger, possibly Earth size or bigger. I doubt a dwarf planet would have that extensive an influence.
Star One:
--- Quote from: clongton on 03/26/2014 06:52 pm ---
--- Quote from: MP99 on 03/26/2014 06:34 pm ---ISTR that Pluto was demoted because it doesn't dominate it's orbit gravitationally (ISTR the Hill sphere came into it).
If this postulated object is "shepherding" Sedna and 2012 VP113, does that mean that it might fit within the definition of "planet" rather than "dwarf planet"?
Cheers, Martin
--- End quote ---
It's possible. For its gravitational effect to be large enough to shepherd these bodies like this it would need to be much larger, possibly Earth size or bigger. I doubt a dwarf planet would have that extensive an influence.
--- End quote ---
Super Earth of the title suggests a planet several times the size of the Earth, but would a body that large be needed to produce these effects?
Be funny if the textbooks had to be revised again back to nine planets.
Bubbinski:
I remember when Sedna was discovered, and 10 years later we've found this new object that orbits even further out.
If this leads to a "super-Earth" it could be our first glimpse of this kind of planet, there have been so many found orbiting other stars but not ours.
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