Jovian Worlds

Majorca Hang

Dr. Asaad Istephan

Principles of Astronomy

23 October 2017

Video Report 4

        The video we watched in class was The Jovian Worlds which talks about Jupiter, Saturn, Uranus, and Neptune. Astronomers think that the snowline had help create these planets because of how gaseous it is. There are more collisions of water and ice. The gas is also contracted in the cores of all the Jovian Planets. There is a theory on how Neptune and Uranus were formed called the Outer Solar Nebula. Which I thought was kind of cool because it means that there are more out in the universe. The video is also focused on Jupiter and how unique it is. First it talked about Jupiter’s layers which has a core made of rock, then a layer of metallic hydrogen, next liquid hydrogen, then gaseous hydrogen and lastly, which is the outer layer, is visible clouds. There is no solid surface and the layers are under high pressure and elevated temperatures. The core is equal to 10 Earth masses and is made up of hydrogen compounds of metals and rock. Jupiter has a strong magnetosphere. Jupiter’s atmosphere has hydrogen compounds in form of clouds. There are different cloud layers that correspond to freezing points to different hydrogen compounds. The red spot on Jupiter is a storm that is twice as wide as Earth and has existed for three centuries. There are strong storms and winds on Jupiter as well. Jupiter was talked about a lot in this video because it is the largest Jovian planet/planet in general. It has four moons that also was talked about named Io, Europa, Calisto, and Ganymede. The theory is that these moons were formed during the solar nebula. Io is made up of metal and rock and has a two day orbit. Europa is made up of metal, rock, and has a thin skin with water inside it. Calisto is made up of water that condenses and has a two week orbit. Lastly, Ganymede is made up of water. When the moons distances become closer, they get squished and becomes a bulge. This is called tidal heating. Tidal heating may have cracked Europa. The next thing the video talked about was Saturn. The rings of Saturn are 270,000 km and there source is a mystery. The rings are not stable and they are not from leftover planetesimals. Jupiter and Saturn both radiate more heat than what they receive. The last thing they talked about was the Ice Giants which are Uranus and Neptune. They are different from Jupiter and Saturn because hydrogen and helium still appears. They also didn’t accrete as fast as the other two. They also have less mass and less heat. I think that this chapter is way more interesting and the Jovian planets are way more mysterious because of how far they are.