Overview
This lecture compares the composition and structure of Jupiter and Earth, focusing on differences in their atmospheres, oceans, and surfaces, as well as the effects of pressure on planetary cores.
Jupiter's Atmosphere and Ocean
- Jupiter's atmosphere and ocean are both made primarily of hydrogen and helium.
- There is not enough oxygen or carbon dioxide in the solar system to make up Jupiter's massive atmosphere.
- On Jupiter, the air and ocean are indistinguishable by composition.
Earth's Atmosphere and Ocean
- Earth's atmosphere consists of about 78% nitrogen and 21% oxygen.
- Earth's ocean is made of water (H₂O), which is different from the air above it.
- The boundary between air and ocean on Earth is clear and visible at the surface.
Differences in Planetary Surfaces
- Jupiter, a jovian (gas giant) planet, has no solid surface or land as we define it.
- Terrestrial planets like Earth have a solid surface, even beneath their oceans.
- On Jupiter, the "surface" would be found only deep beneath the thick layers of gas and liquid.
Pressure Effects and Planetary Cores
- The pressure at the bottom of Earth's ocean is enough to crush a human body.
- Jupiter's ocean is much deeper and heavier, resulting in dramatically higher pressures at its core.
- Jupiter's gravity and massive ocean cause extreme compression at the center.
Diamonds in Jupiter's Core
- Under high pressure, carbon transforms into diamonds.
- Jupiter's core likely contains vast quantities of diamonds formed from compressed carbon.
- Extracting these diamonds is impossible due to the immense pressure and inaccessibility.
- If Jupiter's diamonds were brought to Earth, their abundance would render diamonds worthless.
Key Terms & Definitions
- Hydrogen (H₂) — the lightest and most abundant element, main component of Jupiter's air and ocean.
- Helium (He) — an inert gas, the second main part of Jupiter's atmosphere.
- Nitrogen (N₂) — the primary component of Earth's air.
- Oxygen (O₂) — makes up about 21% of Earth's breathing air.
- Jovian Planet — a gas giant like Jupiter, mostly composed of gases with no solid surface.
- Terrestrial Planet — a rocky planet like Earth, with a solid surface.
- Pressure — the force exerted per area, increases with depth in a fluid.
Action Items / Next Steps
- Review the differences between jovian and terrestrial planets.
- Prepare for a deeper study of Jupiter and other planets in upcoming lectures.