Why aren't the gas giant planets stars?

Answer 1

Gas particles (atoms, molecules) composing the atmosphere of a planet have a mass, therefore they are trapped by the gravitational field of the planet. This is not only true for giant planets but applies to all planets with atmosphere.

Answer 2

the reason that gas planets don't combust, and act in the same way of the sun is because of two main facters. The first being that the chemical composition of the Gas planets is a lot different to the Sun. the sun started out as a huge ball of Hydrogen, which combined to make helium atoms, which provided the correct amount of activiation energy to keep the Nuclear Fusion happening, which releases huge amounts of energy. the second is because, technically, the sun isn't burning. it is simply a huge energy release from the Nuclear Fusion happening from the suns hydrogen supplies.

Answer 3

The Sun tends to strip gasses from planets. Neither the solar wind or the heating of the sun is strong enough to push gasses away from the outer planets. This was true when they formed and the giant gas balls have petty much stayed with them because they are so cold and their gravity so strong.

Explanation:

First of all, it heats the gasses. That give the individual gas molecules enough energy to escape the gravitational pull of the planet and escape into space.

Second, there is the solar wind. The Sun sends out energetic particles, particularly protons, that can collide with the gas molecules and strip them from the planets.

The Earth and Venus have lost all of their light gasses but retain the heavier ones. Mars and Mercury do not have enough gravity to do that.

Earth and Venus have a magnetic field that diverts the solar wind and protects the atmosphere. Mars lost its magnetic field and that is thought to be the reason it lost its atmosphere. Mercury never has much of a magnetic field to begin with.

Once you are past Mars, the intensity of the sun is much less and so the heating effect is not strong enough to give the gas molecules enough energy to escape.

The outer planets are cold. The direct sun does not provide much heat and the cores of these planets are small and they weren't as hot as Earth and Mars to begin with. They don't have cores with significant radioactive heat sources since those source are heavy elements and heavy element tended to accumulate closer to the Sun when they ere formed, i.e Mercury, Venus, Earth, Mars.

Finally, the outer planets don't have much of a magnetic field, but the solar wind is less intense and the gravity of the planets is greater so that process has little effect.

While there may be a small solid core to some of the gas giants, the gases have not been stripped off for the reasons described above and we have very massive gas giants far away from the Sun.

Answer 4

The sun itself is a star, with the Earth and other planets rotating around it. Other stars have their own planets and solar systems. Stars are so far apart that their gravitational pull isn't strong enough to pull in other stars. For example, the planet Neptune is about 2.8 billion miles away from the sun, while the next closest star, Proxima Centauri, is 4.24 light years, or 25.44 TRILLION miles away.

Answer 5

Gravity holds it in, just like gravity holds earth's gasses in.

Answer 6

Gas giants are not stars because they do not have enough mass to ignite nuclear fusion.