– How do gas giants not have a surface? Where do asteroids and comets go when they get sucked in? What’s at the center of a gas giant?

Question

This has always baffled me. I can’t really understand how they could just not have a surface no matter how far down you go. Obviously gravity has to pull the gasses together into some more dense form eventually… right?

In: 775

Answer 1

Don’t think of earth gas or atmosphere. We have a pretty small atmosphere compared to Jupiter. The air around earth gets more dense as you travel down. There’s 3 times as much air at sea level then at the top of Mt. Everest, for example.

Now imagine that the earth is way, way bigger. With a much bigger atmosphere. When an earth-level atmosphere, you keep on falling. After about another 90km, the atmospheric pressure is 10 times that of sea level on earth, and the temperature is around 70 Celsius (160 F). So it is already hotter and a lot more dense.

Now, Earth ocean water is quite a bit more dense than this, but if you are an asteroid, any air you rub against creates friction and heat and starts to break you up. An asteroid falling into Jupiter is already hitting way, way more molecules, just from falling through a much bigger atmosphere, and then even after hitting Earth sea-level density, it keeps falling through thicker and thicker atmosphere. All that is going to keep breaking it up and burning it up.