Introduction
Also known as the gas giants, Jovian planets are the four celestial bodies that comprise the outer planets of the solar systems. These are Jupiter, Saturn, Uranus, and Neptune. The name gas planets do not imply that the planets consist of gases through a significant portion of the planet is gaseous in nature. Overall, the predominant elements of gaseous planets are hydrogen and helium. Neptune and Uranus contain high amounts of methane and ammonia. Their cores, however, consist of dense liquid materials such as nickel. A core of rocks under high temperature is situated somewhere at the center of these celestial bodies. The ongoing research is trying to determine the exact location of the core. Dozens of natural satellites accompany Jovian planets.
Differences among Jovian Planets
Indubitably, the most outstanding feature of the Jovian planets has to do with liquid metallic hydrogen. Jupiter and Saturn are massive enough to generate the threshold pressure required to convert liquid molecular hydrogen to liquid metallic hydrogen. Thus, the two planets harbor liquid metallic hydrogen within them. As for Uranus and Neptune, the threshold pressure necessary to convert liquid molecular hydrogen into liquid metallic hydrogen is not reached owing to their relatively small masses. It should be noted that hydrogen is absent from compounds of both Uranus and Neptune.
Samec (2004) explained that as Jupiter, Saturn, and Neptune emit more energy than they absorb from the Sun, unlike Uranus. Surplus energy that emanates from Jupiter and Neptune is because of the processes that took place during the formation of the planets approximately 450 billion years ago. Surplus energy is produced during the liquefaction of helium on planet Saturn. Uranus is, thus, the odd one marking another significant variation in the seemingly congruent properties of the Jovian planets.
Finally, it is noteworthy that the appearances of Jupiter and Saturn are marked by the red, brown, yellow, and orange colors whereas Uranus and Neptune appear blue and slightly green respectively. Each pair of planets is subject to unique atmospheric conditions that determine what colors of the visible light spectrum are absorbed and reflected.
Formation of the Jovian Planets
Contrary to the terrestrial planets, Jovian planets formed further away from the sun where temperatures are significantly lower. Because of the low temperatures, colossal amounts of ice developed. Thereupon, the ice constituted materials that formed the cores of what would be Jovian planets. The created materials were large enough to attract Hydrogen and Helium by gravitational pull. Ergo, large planets were formed by way of the gas capture phenomenon. (Mizumo, Nakazawa, 1988)
It is worth noting that gas capture is responsible for the differences observed in the Jovian planets. Take, for example, the case of the liquid metallic hydrogen. For this compound to form, a planet’s mass must be above a particular threshold mass. The volume of gaseous material captured during the planets’ formative stages directly determines the mass of Jovian planets. In summary, the process of gas capture is the chief determinant of the properties exhibited by Jovian planets including whatever differences the planets may portray. (Samec, 2000)
Conclusion
Though Jovian planets share numerous similarities, they are very different from each other. Both similarities and differences are rooted in gas capture. They have a lot to tell about the origin of the Universe.
References
Mizumo, H., & Nakazawa, K. Primordial Atmosphere Surrounding a Protoplanet and Formation of Jovian Planets. Oxford Journals, 96, 266 – 273. Web.
Samec, R. The Age of Jovian Planets. The Journal of Creation, 14, 3 – 4. Web.