Comments on: Mega-Earth https://habitablezone.com/2014/06/03/mega-earth/ Mon, 13 Apr 2026 02:46:53 -0700 hourly 1 http://wordpress.org/?v=3.3.1 By: ER https://habitablezone.com/2014/06/03/mega-earth/#comment-30876 ER Sat, 07 Jun 2014 03:40:25 +0000 https://www.habitablezone.net/?p=45291#comment-30876 Its 17 times heavier, We don't know how big it is from the info in the article. You say the surface gravity is 3g (I presume you got this information from another article since it isn't mentioned in your link). So this gives us the information we need to calculate its size. If the planet were the same size as earth, its surface gravity would be 17g, so we know it must be bigger. We know the surface gravity is inversely proportional to the square of the radius, so 17/R^2 = 3. or R^2 = 17/3 = 5.66666... and R = sqrt (5.6666...) = 2.3805 So the planet is about 2.4 times the radius of earth, or 19,044 miles in diameter. Its 17 times heavier, We don’t know how big it is from the info in the article. You say the surface gravity is 3g (I presume you got this information from another article since it isn’t mentioned in your link). So this gives us the information we need to calculate its size.

If the planet were the same size as earth, its surface gravity would be 17g, so we know it must be bigger. We know the surface gravity is inversely proportional to the square of the radius, so
17/R^2 = 3.
or
R^2 = 17/3 = 5.66666…
and
R = sqrt (5.6666…) = 2.3805

So the planet is about 2.4 times the radius of earth, or 19,044 miles in diameter.

]]> By: FrankC https://habitablezone.com/2014/06/03/mega-earth/#comment-30840 FrankC Wed, 04 Jun 2014 22:45:02 +0000 https://www.habitablezone.net/?p=45291#comment-30840 when it involves mass and gravity. It seems that this planet, in spite of being 17 times larger than earth, only has about 3G gravity due to it's radius. I would weigh about 540 and that would permanently pin me to the surface but with an oxygen rich atmosphere I would probably survive for a few minutes until the pressure did me in. Anyway, there is the possibility of some interesting life on such a planet when it involves mass and gravity. It seems that this planet, in spite of being 17 times larger than earth, only has about 3G gravity due to it’s radius.

I would weigh about 540 and that would permanently pin me to the surface but with an oxygen rich atmosphere I would probably survive for a few minutes until the pressure did me in.

Anyway, there is the possibility of some interesting life on such a planet

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