Chapter 8 Quiz: Olivia Ward

1. What are jovian planets made of?
   
   Jupiter and Saturn are primarily made up of hydrogen and helium. Uranus and Neptune are mostly made up of hydrogen compounds as well as metal and rock. The four planets started off as similar-sized icy planetesimals, but captured different amounts of hydrogen and helium from the solar nebula.
   
2. What are jovian planets like on the inside?
   
   Jovian planets have layered interiors with high internal pressures and temperatures. The very high pressures in Jupiter and Saturn can produce metallic hydrogen. All of them have a core that's about 10 times as massive as Earth that consists of hydrogen compounds, metals, and rock.
   
3. What is the weather like on jovian planets?
   
   Jovian planets all have cloud layers that make them appear to be certain colors. They also have fast winds and large storms. The Great Red Spot, a storm on Jupiter, has lasted for centuries.
   
   
4. What kinds of moons orbit the jovian planets?
   The moons are categorized according to size: small, medium, and large. The level of geological activity depends on the moon's size. The small moons greatly outnumber the medium and large moons.
   
   
5. Why are Jupiter's Galilean moons geologically active?
   
   Io is the most volcanically active object in the solar system. It's interior is kept hot by tidal heating. Europa and Ganymede, may have a deep, liquid water ocean under its crust, which is also due to tidal heating. Callisto is the least geologically active because it does not have orbital resonance or tidal heating.
   
6. What geological activity do we see on Titan and other moons?
   
   Titan has a thick atmosphere which shows evidence of a geologically active surface. Its surface has experienced erosion caused by methane rain. Medium sized moons of Saturn and Uranus show evidence of past geological activity. Saturn's moon Enceladus is geologically active as of today and shows evidence of fountains of ice and water vapor that shoot out from the surface. Neptune's moon Triton also shows evidence of recent geological activity.
   
   
7. Why are jovian moons more geologically active than small rocky planets?
   
   Rock melts are higher temperatures and only large rocky planets have enough heat for activity. Ice melts at a lower temperature and tidal heating can metal internal ice, driving activity in icy jovian moons.
   
   
8. What are Saturn's rings like?
   
   Saturn's rings are made up of small, individual pieces of debris that orbit over the planet's equator. 
   
   
9. Why do the jovian planets have rings?
   
   All four of the jovian planets have rings that form from dust created by impacts on the moons orbiting those particular planets. These particles of dust are continuously replaced.
   
10. Who predicted volcanoes on Io?
    
    Stanton Peale predicted volcanoes on Io.