We managed to escape our gravity well with technology from the 20th century.
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.
Yeah if Earth’s gravity is 9.8 m/s2, I think that would mean a planet twice the mass would have a gravity of ~96m/s2. 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
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.
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.
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
The implication is that they can’t explore the universe because the gravitational pull of their planet is to big to escape?
We managed to escape our gravity well with technology from the 20th century.
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.
:history-channel:
wiki it says the gravity is 12.43 m/s2
Apparently much less dense
Yeah if Earth’s gravity is 9.8 m/s2, I think that would mean a planet twice the mass would have a gravity of ~96m/s2. 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
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.
Fg=G(m_1 * m_2)/r^2
Aw hell, this is how we get Stargates
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
Super soaker spaceship
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
Its likely a hycean world, so closer to neptune than a really really deep ocean world.