Jupiter Module 5

Module 5: Jupiter

Observations of Jupiter from Earth

  • Visibility: Third brightest object in night sky.

  • Size: Largest planet in the solar system.

  • Telescope Observations:

    • Simple telescopes can reveal moons and alternating color patterns.

    • Notable features include bands and ovals.

  • Moons: Jupiter has many moons.

    • Galilean Moons: Name given to its four largest moons.

Jupiter's Atmosphere – Two Main Features

  • Cloud Bands:

    • Features numerous parallel cloud bands of varying colors (yellow, blue, brown, tan, red).

  • The Great Red Spot:

    • A massive, hurricane-like storm that is three times the size of Earth.

    • Has persisted for hundreds of years.

Jupiter's Atmosphere – Composition

  • Composition:

    • Hydrogen: 86% (most abundant)

    • Helium: 14%

    • Other gases: Methane, ammonia, water vapor.

  • Coloration:

    • No single gas is responsible for the planet's colors.

    • Colors are due to chemical processes occurring in a turbulent atmosphere.

    • Trace gases such as sulfur and phosphorous contribute reds, browns, and yellows.

  • Energy Sources: Internal heat drives energy for these reactions; the magnetosphere and lightning also play a role.

Jupiter's Atmosphere - Bands

  • Light and Dark Bands:

    • These bands vary with latitude and intensity but are always present.

    • Explored by space probes Voyager and Cassini.

  • Convection Mechanism:

    • Zones: Areas of upward motion.

    • Belts: Areas of sinking air.

Jupiter's Atmosphere

  • Belts & Zones:

    • Pressure areas control weather patterns.

    • Bands wrap around the planet with cloud formation at different heights.

    • Temperature differences affect cloud chemistry, resulting in varied colors.

Jupiter's Atmosphere – Jet Stream

  • Stable Zonal Flow:

    • Features east-west flow mainly at the equator, termed the easterly jet stream.

    • Poles exhibit a slow, steady flow without distinct bands.

Layers of Jupiter's Atmosphere

  • Troposphere: The uppermost layer with distinct colored cloud layers below.

  • Convection: Controls cloud distribution.

  • Haze Layer: Found above the troposphere.

    • Clouds Composition:

      • Ammonia Ice Clouds: Up to 30km high with temperatures between 125-150 K.

      • Ammonium Hydrosulfide Ice Clouds: Found below ammonia clouds at around 200 K.

      • Water Vapor & Ice Clouds: Located 80 km beneath the troposphere top.

Galileo Atmospheric Probe Observations

  • Key Measurements: Wind speed, temperature, composition confirmed theoretical models.

  • Altitude Observations: 0 km to 200 km.

  • Stratosphere and Troposphere: Information on pressure and temperature profiles across atmospheric layers.

Jupiter's Weather

  • Great Red Spot:

    • Active for over 300 years, it resembles a hurricane and has been studied by Voyager and Galileo missions.

    • Persistent and large, spans about 25,000 km and engulfs smaller storms while rotating with Jupiter's interior.

Jupiter’s Weather – Zonal Flow

  • Movement:

    • Northward motion is west, while southward is east.

    • Exhibits turbulent eddies with calmer centers.

  • Voyager Discoveries: Identified smaller storms, including white ovals (high cloud tops) and brown ovals.

    • In 2006, a spot changed from white to brown to red, indicating a strong storm that lifted clouds underneath due to UV radiation-induced chemical reactions.

Jupiter’s Weather – Small Storms

  • Similar color changes have been observed in smaller storms, with the red color indicating a strong storm activity due to the same UV radiation reactions.

Jupiter’s Interior

  • Temperature & Pressure: Increase steadily with depth; stratified into gas and liquid layers.

  • Hydrogen Mantle: Exists in a metallic state, behaving like a liquid metal, which helps conduct heat and forms Jupiter's magnetic field.

Jupiter’s Interior - Core

  • Core Characteristics:

    • Bulging at the equator, indicating a more complex structure than just hydrogen and helium.

    • Dense core possibly composed of molten or semi-solid rock with iron, with a diameter of about 20,000 km.

Magnetosphere

  • Magnetic Field Strength: A strong magnetic field, produced by rapid rotation and electrically conductive fluids.

  • Size: 20,000 times stronger than Earth’s, with an uneven structure:

    • Sun-side extends approximately 3 million km, while the opposite side reaches up to 600 million km.

    • Overall magnetosphere spans 30 million km, exceeding the size of the sun.

Aurorae

  • Occurrence: Similar to Earth's auroras, caused by charged solar wind particles being deflected into Jupiter’s atmosphere by its magnetic field.

Internal Heating

  • Temperature Insights: Originally thought to be around 105 K; actual measurement reveals it to be approximately 125 K.

  • Heat Source: Results from residual heat from formation; the interior used to be hotter than it currently is, and heat leaks drive storm formation, being trapped by cloud layers.