Jovian planets, which include Jupiter, Saturn, Uranus, and Neptune, are truly giants in our solar system. Jupiter’s mass is 318 times that of Earth. Jovian planets, sometimes called the “gas giants“, are truly the giants of our solar system. All of these planets were named for the Roman god Jupiter, since people presumed that they were all similar in composition to the planet of the same name. We now know that while all four planets are still within the same category, Uranus and Neptune are very different.
These planets, further away from the sun, did not develop the rock and metal cores that are found on Earth and other terrestrial planets. They did, however, once they grew to a good size, begin to incorporate helium and hydrogen from the nebula of their birth. Jupiter and Saturn are examples of two planets that grew to massive proportions, however, Neptune and Uranus, although large, were deprived of these added resources.
These are inhospitable planets, with no solid surface. They do, however, become more dense toward the core, gradually becoming less and less dense as the distance increases from the center. Through the force of gravity, when these were formed, rocks and more solid materials were pulled to the center. Jupiter and Saturn are composed of hydrogen and helium, while Neptune and Uranus, sometimes called “ice giants”, are made primarily of ammonia, water, and methane.
All Jovian planets have rings. When any body, an asteroid, comet, or moon approaches these planets and are within the Roche limit, or the minimum distance a satellite can approach without being destroyed by the tidal force of the planet, they are torn apart and become part of the rings system. How bright these rings appear depends on how large the particles are in the ring. These range in size from dust particles to the size of a house.
Jovian planets also give off more radiation than they take in, because they are far from the sun. Radiation that is given off was left over from the process of their creation. They also have high magnetic fields.
Over all, these gas giants are impressive to say the least, but hardly candidates for human exploration. How they formed, and grow are, however, important to the understanding of the development of our solar system.
"Jovian Planets." Mac OS X Server. Web. 15 Feb. 2011. http://abyss.uoregon.edu/~js/ast221/lectures/lec15.html.
JOVIAN PLANETS." Web. 15 Feb. 2011. http://www.physics.uc.edu/~sitko/Fall2002/11-JPint/jp-int.html.