/sci/ - Science & Math

>>8179046
Jupiter started as a terrestrial body like Earth when the solar system was forming, but much larger.

It was big enough that its gravity was able to keep hydrogen and helium from escaping into space (their escape velocity is so low that planets the size of Earth cannot hold on to them as atmospheric gas) so it and the other giants kept growing in size until all the available hydrogen gone.

The hydrogen that is deep inside is under so much pressure that it is in a metallic form, and its generates Jupiter's monstrous magnetic field.

The Juno probe should be able to get a good idea of how deep the metallic hydrogen is, and how large the core is.

tl:dr deep down inside of Jupiter is a super or mega Earth surrounded by gorillions of tons of hydrogen/helium.