# What would a 2 Earth radii and 9 Earth mass planet be like?

Could life be there?

### 6 Answers

- CarolOklaLv 72 months agoFavorite Answer
Yes, life definitely could be there. Carbon based life. As long as water is there, including ice, with liquid water underground, and the right temperatures because of a hot core or tidal flexure, life definitely could exist. We may have a super Earth in our own planetary system. Dr. Michael Brown and his team and at least one other team have been looking for planet 9 for years.

- SciencenutLv 72 months ago
I once read an article on this subject. The author posed the hypothetical thought that suppose you took ~10 planets identical to Earth and blenderized them into a huge glob of "Earth stuff". Then let's say you dole out this Earth stuff into different sized quantities and then see what kind of planets might arise. Of course, a one earthmass glob of earthstuff would wind up being more or less just like our Earth. A 1/10th mass glob of earthstuff would produce a planet with a radius of the radius of Earth divided by the cube root of 10. This calculates to a planetary diameter of ~1/2 that of Earth, with 1/10th of the water and atmosphere spread over ~1/2 of the surface area, yielding a planet with ~20% atmosphere and ocean depth. In short, such a planet would somewhat closely resemble the planet Mars.

Now imagine a planet made of ~8 earthmasses of earthstuff. Such a planet would have a radius twice as large as Earth with four times the surface area of Earth. But there would be 8 times as much atmosphere and ocean, spread over four times the surface area, yielding a planet with an ocean twice as deep and an atmosphere twice as thick. The surface gravity would be double that of Earth, making tall mountains and even dry land continents all but impossible. It would be a "water world" for sure. And the dense atmosphere would have a much greater greenhouse effect. This enhanced greenhouse effect would boil away all the oceans, producing a surface pressure of ~100 Bar in a perpetually cloudy Hydrogen rich atmosphere. In short, such a world would more closely resemble a planet somewhere between a Venus and a Jupiter, rather than resembling anything like Earth.

But a 1/2 earthmass glob of earthstuff would produce a planet with a radius of one earth radius divided by the cube root of 2, which is ~80% of an Earth radius, with 1/2 the atmosphere and ocean spread over ~2/3 of the surface area, yielding an atmosphere ~80% of Earth and an ocean ~80% as deep as Earth. Such a planet might easily support life.

Cheers.

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- DeMoNsLaYeR575Lv 72 months ago
it would have roughly 2.4x the gravity at surface level.

the change in mass is 9 times

new g = g * 9

this takes care of the mass change

the radius change is a division by the square

new g = g / 2^2

putting them together you get

new g = (g *9)/4- Login to reply the answers

- AshLv 72 months ago
Jupiter has 11 times Earth radius and 318 times more mass.

We have not yet found life there

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Thank you!😀🎓😉