Jupiter and Saturn - In Depth Notes

General Characteristics
- Images show relative sizes of Jupiter and Saturn, with distinct features.
- Jupiter:
- Dark belts (low-pressure zones) and light zones (high-pressure zones) create a banded appearance.
- Dark belts are hypothesized to contain hydrocarbons that darken under UV light.
- Lighter zones consist of high-altitude ammonia ice clouds reflecting sunlight.
- Saturn:
- Exhibits similar but more muted belt-zone circulation than Jupiter.
Belt-zone Circulation
- This atmospheric structure results from convection where warm air rises and cold air falls.
- Influenced by the Coriolis effect due to rapid rotation.

Wind Characteristics
- Extreme wind speeds observed:
- Jupiter: up to 620 ext{ km/h} (390 ext{ mph}).
- Saturn: up to 1,800 ext{ km/h} (1,100 ext{ mph}).
- For reference, hurricane winds on Earth reach a maximum of 400 ext{ km/h} (250 ext{ mph}).
Great Red Spot (Jupiter)
- A massive storm observed for over 300 years, with continuous observation for the last 200 years.
- Current dimensions: oval shape, 25,000 ext{ km} (length) and 12,000 ext{ km} (width).
- Two Earth-sized regions could fit within it.
Little Red Spot (Red Spot Jr)
- Formed from merging three storms in 1998, intensified in 2006.
- The reason for its red color is under investigation, possibly due to material from lower atmosphere.

Major Storm (2010)
- A storm with a vortex larger than Jupiter's Red Spot formed in Saturn's northern hemisphere.
- Released ethylene gas and significantly altered local temperatures.
Hexagonal Jet Stream
- Unstable hexagonal feature observed at Saturn's north pole; its origins are under research.

Main Components
- Jupiter and Saturn's atmospheres primarily consist of hydrogen (H) and helium (He).
- Layered structures include:
- Ammonia ice (NH_3)
- Ammonium hydrosulfide (NH_4SH)
- Water (H_2O)
Ice Clouds
- Ice exists as aerosols with observed colors arising from chemical reactions involving lightning and sunlight.
- Saturn has thicker ice layers due to lower gravitational pull.

Core Composition
- Jupiter and Saturn both possess rocky cores surrounded by layers of metallic hydrogen, liquid hydrogen, and gaseous hydrogen.
- The transition between gaseous and liquid hydrogen occurs at various depths.
Physical Properties
- Similar internal pressures and temperatures, resulting in a smooth transition to metallic hydrogen, a good electric conductor responsible for their magnetospheres.

Key Characteristics
- At rac{1}{4} R_{Jupiter} within its interior, pressure forms metallic hydrogen.
- Contains approximately 30 M_{Earth} of heavy elements with most suspended in convective hydrogen.
- Density: Specific gravity (SG) of 1.33, which is about rac{1}{4} that of Earth.

Key Characteristics
- Lesser amount of metallic hydrogen due to smaller mass leading to lower pressure.
- Saturn radiates about 2.5 times more energy than it receives from the Sun, a phenomenon requiring further explanation.

Conditions for a Magnetosphere
- Need conductive fluid, convection of that fluid, and rotation around an axis.
- Both Jupiter and Saturn have significant magnetic fields and large magnetospheres, stronger than Earth's.
- Jupiter's magnetic field is approximately 20,000 times stronger than Earth's.

Radiation Levels
- Spacecraft enter intense radiation zones leading to significant radiation exposure, harmful to electronics.
- Auroras on Jupiter significantly exceed those on Earth in luminosity (up to 1000 times brighter).

Observed in 1994, this comet was captured by Jupiter’s gravity, leading to its fragmentation and impact with the planet.
Significant for being one of the first major astronomical events shared live via the Internet.
Jupiter serves an important protective role for Earth by attracting comets and asteroids that might endanger our planet.