Anonymous asked in Science & MathematicsAstronomy & Space · 4 weeks ago

Can a planet exist that is 2x Earths radius and has a mass of 10 Earths and be a rocky planet or not?

Could a planet like that happen or does it always have to be a mini Neptune? How could a rocky planet that big exist? Formation in inner solar system?

6 Answers

  • Roger
    Lv 7
    4 weeks ago
    Best answer

    A planet with twice Earth's radius would have 8 times its volume. With a mass of 10 times Earths, its density would be 1.25 times Earths (5.51 grams per cubic centimeter).  The planets density would 6.89 grams per cubic centimeters. It would be rocky planet. 

    It could form in a planetary system with a more massive sun than ours, and it would probably form in the inner region. There is less hydrogen and helium gas in inner region than in the outer regions. 

  • 3 weeks ago

    May be, a planet twice the size of Earth with eight times the mass has been discovered in 2015. Scientists named it as K2-18b. What more exciting is that there have been speculations made about the scope of life on k2-18b. Right now k2-18b is the only planet with correct temperature for life and water outside the solar system.

    Source(s): Simply Raw .WATER FOUND ON PLANET K2-18B! IS ANOTHER ‘EARTH’ POSSIBLE? Retrieved from
  • 3 weeks ago

    Anything "could" exist, within reason. The question is whether such a planet does exist and is close enough for us to confirm it's existence.

    Until such confirmation is ever found, the pop-sci articles will keep proclaiming it "could" exist, and keep reporting that the latest find "may be" such a planet.

  • 4 weeks ago

    Yes. A larger rocky planet would be a common formation. As for density, likely in proportion and of course a greater mass.

    Its position in orbit of a star could well be smaller than the diameter of Neptune.

    • Zirp
      Lv 7
      3 weeks agoReport

      radius of the orbit smaller than the radius of a planet? no way...

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  • 4 weeks ago

    Yes, a planet like that definitely can exist, and it would not have to be a mini Neptune. It would be a terrestrial rocky planet, a super Earth. 

    We have  and are detecting exo super Earths for several years. Planets do not necessarily form where they are today. Jupiter probably formed closer the Sun and migrated out to where it is now. Saturn may have done that too. Earth and the terrestrial planets may be a second generation planets. ALL planets have rocky cores that have chemically differentiated to have a solid inner core a liquid outer core and a viscous mantle , and a crust. There MIGHT be a metallic hydrogen surface. The clue is the planet has a GLOBAL magnetic field and relatively rapid rotation. A planet made of mostly gas would dissipate fairly quickly without a rocky core to anchor all that gas and ices for millions or billions of years. 

    The question is WHY our Solar System does NOT have a super Earth, unless the still visually unconfirmed planet 9 is a super Earth. Planet 9 may have been gravitationally captured from a other star. 

    Source(s): "How the Universe Wirks," "The Planets," TV shows, Science Daily, Live Science, Scientific American, space com.
  • Anonymous
    4 weeks ago

    Your question makes no sense.

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