The chart below shows the “depth” of various Solar system gravity wells.
Each well is scaled such that rising out of a physical well of that depth – in constant Earth surface gravity – would take the same energy as escaping from that plants gravity in reality.
Each planet is shown cut in half at the bottom of its well, with the depth of the well measured down to the planet’s flat surface.
The planet sizes are to the same scale as the wells. Interplanetary distances are not to scale.
It takes the same amount energy to launch something on an escape trajectory away from Earth as it would to launch it 6,000 km upward under constant 9,81 m/s2 Earth gravity. Hence, Earth’s well is 6,000 km deep.
This is why it took a huge rocket to get to the Moon but only a small one to get back.
Jupiter is not much larger than Saturn, but much more massive. At its size, adding more mass just makes it denser
If you dropped a few dozen more Jupiters into it, the pressure would ignite fusion and make it a star.
– Lakes and oceans depth comparison