I assumed gravity would be more than 14% of the gravity on Earth but just found out the size of Neptune is a lot smaller than I had imagined. It's only 4 times the diameter of Earth, while Jupiter is 1,300 times the diameter of Earth. I didn't realize the size difference between the two were so far off.

[–] freeman@lemmy.pub 2 points 1 year ago

To be fair jupiter is 99% of the mass in the solar system (that isnt the sun).

The sun is 99.8% of the mass of the entire system

Of the rest of the .15-.2% of the mass left, Jupiter is like 2.5x bigger than the rest of the stuff combined.

Jupiter is really big. So if the sun.

[–] FlyingSquid@lemmy.world 1 points 1 year ago (2 children)

Isn't Neptune a gas giant and thus has no surface?

[–] freeman@lemmy.pub 5 points 1 year ago

The reality is we dont really know. The "surface" in this article is where the pressure is largely 1 atm. And at that pressure its mostly liquid (albeit hot)

[–] shadowspirit@lemmy.world 3 points 1 year ago* (last edited 1 year ago) (1 children)

That's a good question that hopefully someone more learned will be able to respond to but you know most of the Earth's surface is water so I suppose Neptune has a surface. I don't know what the technical definition is but I'm assuming it's where particulate / molecules in the atmosphere change states due to temperature and pressure. A bit like how we have H2O in the form of gas as water vapor in the atmosphere and at the surface a liquid as water. The closer you are to the center of the planet the higher the pressure and the temperature.

[–] octoperson@sh.itjust.works 3 points 1 year ago

If the pressure is high enough, you can get a smooth transition between gas and liquid without any sort of boundary that you could identify as a surface. That's thought to be what happens on Jupiter, don't know about Neptune