Why are the jovian planets so large?

Question

This ia about astronomy

Answer 1

They are gaseous and are a considerable distance from the sun. They don't have the density that the terrestrial planets have, but they are comprised of quite a bit of matter, and that tends to make them larger in size.

Some of the moons of Jupiter and Saturn are very earth-like. The moons are generally part of the planetary systems of these large planets, but their composition is very different from their host planets, which are star-like in some respects.

Answer 2

Terrestrial planets are essentially the cores of Jovian planets. All the Jovian planets have rocky, earth-like cores under tremendous pressure because of the much greater mass of the outer layers of gas, but that's only because the heavier elements settle to their cores. The earth is composed of heavy elements, mostly silicon, oxygen, and iron. The Jovian planets consist mostly of hydrogen and helium, but their cores are similar to earth's makeup. The inner planets probably lost their outer atmospheres in the sun's T-Tauri phase during its early formation, when solar winds were strong enough to blow them into interstellar space. The outer planets' outer atmospheres most likely survived because they were far enough away. Other stars have Jovian planets much closer to their parent sun probably because their T-Tauri phase started later, after the Jovian planets had already formed. The difference in evolutionary development is probably rooted in the amount of heavy elements that make up a star itself, which is a result of it being a 1st, 2nd, or 3rd generation star. Later generations contain more heavy elements as a result of supernovas adding to their makeup. I hope this rant made sense.

Answer 3

If it were not for the solar wind, it is likely that all of the planets would be Jovian. The terrestrial planets probably lost their large, mostly hydrogen atmospheres not long after the sun became a main sequence star. The outer planets are far enough away that their gravity can hold on to the lighter gases.

Answer 4

Depends do you mean the outher gas giants - Jupiter, Saturn, Uranus, and Neptune?

If so, then (as we know it) the Sun's gravitational and solar wind forces have prevented the closer planets from keeping their hydrogen atmostpheres, in addition to heavier elements (rocks, etc) circling the sun closer. However the discovery of gas giants orbiting close to other stars is throwing this theory away. We simply do not know yet.

If you mean Jupiter's moons (and not planets - a realistic possiblility since Jupiter's main moons are among the largest in the solar system). Then, the answer is definately - because of the high mass and gravitational pull of Jupiter as compared to the rest of the planets, Saturn is the next biggest, but only has roughly 1/2 the mass of Jupiter.

Answer 5

Do you mean the outer gas giant planets (Jupiter, Saturn, Neptune, Uranus) or the satellites/moons of Jupiter?

If it is the second one, the gravity of Jupiter is massive enough to attract space matter from the outer solar system into orbit around the planet. As more matter is drawn in, it inevitably collides with each other to form bigger and bigger moons around Jupiter.

If it is the first one, these planets are mainly gas, which is less dense than solid matter - thus, they have larger volumes.

Answer 6

The 4 jovian planets:Jupiter, Saturn,Uranus and Neptune are well located away from the sun and have got enough gravity to snatch particles to add.

Answer 7

Pot luck man. You can dispute this but then you would have to assume one of the many different ways planets are thought to be formend. But we don't know which one is correct so the best reason would be: 42