What exactly happens on a gas planet and if they aren’t able to be walked on, then why are they considered “planets”?


What exactly happens on a gas planet and if they aren’t able to be walked on, then why are they considered “planets”?

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>What exactly happens on a gas planet

In what sense? This question doesn’t really make any sense. What happens on a terrestrial planet?


>if they aren’t able to be walked on, then why are they considered “planets”

Because “being able to be walked on” is not part of the definition of a planet. A planet, by definition, is a body that orbits a star, has enough mass to assume hydrostatic equilibrium (be a nearly round shape), and has “cleared the neighborhood” around its orbit (meaning it has sufficient gravity to clear its orbit of other large objects). Having a solid surface is NOT a requirement for being a planet.

Gas planets are massive. To the point that the physics involved isn’t what people are used to or have an easy idea picturing.


Imagine falling though 1000 miles of air getting thicker and thicker. The air eventually gets thicker and thicker something like fog, and without a distinct point you find yourself in liquid. Except that liquid isn’t water it’s the same gases just squeezed together so much its like water. Fall another 1000 miles and the liquid gets thicker and thicker, at first like honey, then near the end like jello. At which point you stop falling quickly. The ‘ground’ is still jello, something between a liquid and solid.


There are solids deep inside a gas giant but they are so far down and under such a high pressure the ‘surface’ wouldn’t be anything we humans would picture as a ‘surface’.

The main elements of gas planets are hydrogen and helium.Since there is no flat surface on them, you cannot walk on them. Winds on a gas planet may reach speeds of hundreds of miles per hour, creating a very chaotic environment.

With temperatures approaching millions of degrees Fahrenheit, a gas planet’s interior is likewise extremely hot.

They are considered planets because they meet the three criteria that are used to define planet:

They orbit a star.

They have enough mass for their own gravity to clear the neighbourhood around their orbit.

They are not a star.

The IAU (International Astronomical Union) has made a clearer definition for what a planet is.
They said: “A planet is a celestial body inside the Solar System that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape, and (c) has cleared the neighbourhood around its orbit.”

So Gas Planets still fit into the definition of a planet.
Also, all Gas Planets in our Solar System have a solid core so they aren’t completely made out of Gas but the Gasses are so much more prominent that they are considered Gas Planets.

Wow!!! Thanks sooooo much for all the explanations. Space is sooooo cool. I can’t wait to get my little one into space and astrophysics