K2-18bians could be at our technological level and still not escape their gravity well. I think a planet twice as big as ours would require rockets as heavy as the pyramids of Giza just to reach orbit, never-mind exiting their planet's orbit into deeper space.

[–] Meltyheartlove@hexbear.net 48 points 3 days ago (1 children)

[–] Le_Wokisme@hexbear.net 38 points 3 days ago (1 children)

:history-channel:

[–] peeonyou@hexbear.net 2 points 2 days ago* (last edited 2 days ago)

curry-space

[–] FuckyWucky@hexbear.net 42 points 3 days ago* (last edited 3 days ago)

wiki it says the gravity is 12.43 m/s2

Apparently much less dense

[–] Sulv@hexbear.net 25 points 3 days ago* (last edited 3 days ago) (2 children)

Yeah if Earth’s gravity is 9.8 m/s^2^, I think that would mean a planet twice the mass would have a gravity of ~96m/s^2^. Correct me if I’m wrong physicist hexbears.

Edit: upon cursory reading it seems much more complicated than this. Basically the force needed to leave the gravitational pull doesn’t necessarily directly correlate to the gravity exerted by the object, size and distance are involved too

[–] ZWQbpkzl@hexbear.net 15 points 3 days ago* (last edited 3 days ago)

Twice the mass is twice force twice the acceleration. Gravitational force is linear to the mass of one of the objects. It would be 19.6m/s2 if the radius was the same but the radius is larger and that's inverse quadratic. Double the radius, quarter the acceleration. Although I really doubt that planet is only double our mass.

2.6x the radius of earth, 8.63±1.35 the mass of earth.

[–] gay_king_prince_charles@hexbear.net 1 points 2 days ago

Fg=G(m_1 * m_2)/r^2

[–] SkingradGuard@hexbear.net 13 points 3 days ago

I think a planet twice as big as ours would require rockets as heavy as the pyramids of Giza just to reach orbit, never-mind exiting their planet's orbit into deeper space.

Aw hell, this is how we get Stargates

[–] CeliacMcCarthy@hexbear.net 38 points 3 days ago (3 children)

it's gravity, yes, but also that this is almost definitely an ocean planet with no land. Good luck developing metallurgy underwater, to say nothing of fossil fuels etc

[–] Sulv@hexbear.net 31 points 3 days ago

Super soaker spaceship

[–] Person@hexbear.net 13 points 3 days ago

But also if it's an ocean planet and doesn't have a dense iron core, it's gravity won't necessarily be greater than the Earth's

[–] Lemister@hexbear.net 3 points 3 days ago* (last edited 3 days ago)

Its likely a hycean world, so closer to neptune than a really really deep ocean world.