In recent space news, I learned about Jupiter not being an exactly spherical planet (WHAAAT?). According to bad astronomy blog, Jupiter naturally has an oblate shape that is due to the speed at which this planet is spinning, causing the centrifugal force to fling material out from its equator, making it a 3-D oval (or an egg, I guess). This information led me to think about the properties of the planets in our solar system that were discussed in lecture.
We have learned about the characteristics of our solar system and how it was formed. To begin with, we are all familiar with the Sun being the center of our solar system, orbited by 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Each of these planets is pulled in by the sun’s gravity, illuminated by its light, warmed by its rays, and shaped by the charged particles it gives off. The 4 inner planets (Mercury, Venus, Earth, and Mars) are small, composed of metal and rock, and more tightly spaced as opposed to the outer 4 planets. Due to their composition, these planets are referred to as the terrestrial planets, however they are very different on the surface. Mercury is heavily cratered, dry, and desolate; Venus is hot, molten, and vicious; Earth is the only livable planet, with its liquid water; and finally, Mars is a mysterious possible Earth number two, with evidence of past existing river beds and other potential life-like attributes. Next, separating the inner and outer planets is the asteroid belt, composed of many small, rock-and-metal chunks floating around the Sun. Beyond the belt are the 4 outer planets (Jupiter, Saturn, Uranus, and Neptune). These planets are regarded as Jovian planets because they are all similar to Jupiter, the largest in the bunch. All four are composed of gases without a solid core, unlike the terrestrial planets which are all primarily rock. If you were to attempt “landing” on any of these planets, you would only plunge deeper into its atmosphere until you would be crushed by the pressure at its core. It is with this notion that I understood why Jupiter can be oblate; Since it is mainly composed of gas, Jupiter does not have the atmospheric pressure near its edge to keep all the material in. Items in the core are held more tightly, but even like our atmosphere on Earth, the pressure feathers out. Unlike terrestrial planets, Jovian planets can have many moons and all four of our solar system’s Jovial planets are orbited around by small particles that make up their rings. Our solar system overall displays similar characteristics between the planets. All planetary orbits are similarly circular and lay within the same plane. They also all orbit in the same direction, and most rotate in the same direction of their orbit around the sun as well.
All of these characteristics lead to the scientific understanding of how our solar system formed. In a Lecture tutorial on the Temperature and Formation of Our Solar System, we learned that distance from the Sun and average temperature were deciding factors on how and why the different planets were created. In the temperature range of about 500-1000 Kelvin and about 0.3-1.25 AU from the Sun created terrestrial planets, while temperatures of about 45-150 Kelvin at a distance of about 5-45 AU created large Jovian planets.
Learning about our solar system not only helped me understand the qualities of our planets (such as Jupiter) and how they came to being, but also, with this information, I can apply understanding of planet types when reading about future space news. I no longer have to act like I know what is going on when I hear about qualities of other planets that are being found beyond our system, and I can hope to take part in space discussions related to this topic. The universe is always expanding and that means more room for new stars, planets, moons, and LIFE. I’m ready for the next big space discovery.