Jovian Moons: the giant planets all have multiple moons, which are composed of rock and ice. Ganymede (orbiting Jupiter) and Titan (orbiting Saturn) are the largest….Overview Of The Solar System.

Comets are frozen leftovers from the formation of the solar system composed of dust, rock and ices. They range from a few miles to tens of miles wide, but as they orbit closer to the sun, they heat up and spew gases and dust into a glowing head that can be larger than a planet.

Instead, rocky materials and metals formed the smaller rocky planets. Farther out, beyond the asteroid belt, ices condensed in the colder reaches of space, forming the cores of Jupiter, Saturn, Uranus, and Neptune — the gas giants — and their moons.

Uranus and Neptune, like Jupiter and Saturn, have small rocky cores surrounded by very thick layers of frozen gases. Because of their great distances from the Sun, though, they are even colder than their giant neighbors.

In terms of life developing on a gas giant? Sure, it’s possible. At best you could have some form of single cell extremophile organism in the uppermost atmosphere. Even this however is unlikely, as Gas Giants are stupidly hot; what their outer atmospheres lack in heat they make up for in cell crushing pressure.

There are layers in the atmosphere of gas giants where the temperature and pressure are inside the limits where life as we know it can exist. It is even possible that larger creatures could evolve, keeping afloat by generating, say, hydrogen as part of their metabolism, keeping it in sacs. A bit like fish on Earth.

The gas giants of our solar system are Jupiter, Saturn, Uranus and Neptune. These four large planets, also called jovian planets after Jupiter, reside in the outer part of the solar system past the orbits of Mars and the asteroid belt.

A gas giant is a large planet mostly composed of helium and/or hydrogen. These planets, like Jupiter and Saturn in our solar system, don’t have hard surfaces and instead have swirling gases above a solid core.

The four gas giants in our solar system are Neptune, Uranus, Saturn, and Jupiter. Jupiter is about 11 times the diameter of Earth, Saturn 9 times, and Uranus and Neptune about 4 times Earth’s diameter. A gas giant is a GIANT planet that is made of gas!

So inconspicuous that it was not discovered until 1930, Pluto is not a gas giant planet like all the others in the outer solar system. Instead it is a small, rocky world about the size of Earth’s Moon. Pluto now seems to be about 3000 to 3500 kilometers (1900 to 2200 miles) in diameter.

There are the inner, rocky terrestrial planets and then the outer gas giants. Venus is a terrestrial planet. The terrestrial planets are the 4 inner rocky worlds in the Solar System: Mercury, Venus, Earth and Mars. But compare a terrestrial world like Venus to the gas giants like Saturn and Jupiter.

Our home planet Earth is a rocky, terrestrial planet. It has a solid and active surface with mountains, valleys, canyons, plains and so much more.

Planet Venus is a rocky planet covered with extremely thick layers of atmosphere, making it impossible to glance its surface from Earth.

It has a thick atmosphere full of the greenhouse gas carbon dioxide and clouds made of sulfuric acid. The gas traps heat and keeps Venus toasty warm. In fact, it’s so hot on Venus, metals like lead would be puddles of melted liquid. Venus looks like a very active planet.

No. A gas giant will never have sufficient mass to become a star on its own. The only way to form a star is for a sufficient mass to accumulate for pressures necessary for fusion to occur.

Jupiter, Saturn and Neptune, the three immense gas giants in the outer solar system, all have atmospheres made up of mostly hydrogen. That’s a chemical that when it’s in gas form on Earth, can be explosively combustible. It’s also the chemical that the sun uses for fuel.

Neptune

A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are sometimes known as failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System.

Jupiter twin orbits a twin of our sun – Exoplanet Exploration: Planets Beyond our Solar System.

The dark color is believed to be the result methane and nitrogen in the atmosphere interacting with ultraviolet light and cosmic rays, creating the dark particles (“tholins”) common to Pluto. And then there are the “Brass Knuckles”, a series of equatorial dark areas on the leading hemisphere.