Jupiter Astronomy 311 Professor Lee Carkner Lecture 17

Jupiter -- King of the Gods   Jupiter is also “King of the Planets” due to its size

Viewing Jupiter from Earth  Is very bright from Earth   In opposition every 13 months   Can clearly see cloud patterns, Great Red Spot and 4 largest moons even with small telescope

Jupiter Facts  Size:  Orbit: 5.2 AU  Description: large, gaseous, many large satellites

Viewing Jupiter from Space   Currently observed by Hubble Space Telescope   The Galileo spacecraft ended its mission in 2003   Dropped a probe through the atmosphere

Galileo’s Atmosphere Probe

Galileo Atmosphere Probe  Launched from the Galileo spacecraft on Dec 7, 1995   Lasted for 1 hour and got down to 130 km below the tops of the clouds before the high temperature and pressure killed the electronics

Shoemaker-Levy 9   Passed too close to Jupiter and was torn apart by tidal forces   Each piece created a huge fireball  Spectra of impacts reveals composition of deeper layers of atmosphere

Convection   Produced by convection   Hot material rises and cooler material sinks  Jupiter has the most prominent clouds and belts of any planet  Because it has the most internal energy

Belts in Jupiter’s Atmosphere

Jupiter’s Rotation  Jupiter has a rotation period of about 10 hours   This rapid rotation shapes the belts and zones into oppositely circulating bands   equator rotates faster than the poles  this is because Jupiter is not a solid body

Structure of Jupiter’s Atmosphere  Infrared, radio and Galileo probe observations reveal 3 cloud layers   Ammonium hydrosulfide (NH 4 SH)   The color of the layers depends on depth  Brown --  White -- middle layer  Red --  Not all layers are found in all regions  Galileo found no water

Cloud Formation   Will only happen at a specific combination of temperature and pressure   Clouds only form in one spot in the atmosphere  Above and below, compound is all liquid or all gas

Structure of Jupiter’s Atmosphere

Spots and Ovals   They are rapidly rotating cloud features (storms)  Some are very long lived   Some spots are white or brown   Brown ovals may be holes to the deeper, hotter, inner atmosphere

Interlude Gravity  Every object in the solar system pulls on every other due to gravity  This can cause perturbations in orbits   We can use a modified version of this equation which shows the relative force a planet exerts: F=M/D 2

Jupiter’s Interior   Small core of rock and ice (about the size of the Earth)   Liquid metallic hydrogen outer core (40-50,000 km thick)   Hydrogen gas layer 10-20,000 km thick

The Interior of Jupiter

Rings  Jupiter’s rings were discovered by Voyager   May be formed from material chipped off of 4 small inner moons by impacts

Diagram of Jupiter’s Rings and Inner Moons

Jupiter’s Moons   Jupiter has a planetary system of its own   Jupiter has 4 of the 7 large moons of the solar system

Jupiter’s Magnetosphere

  The magnetic field forms a magnetosphere about 200 times larger than Jupiter itself   Also contains:  a hot, thin, rapidly changing plasma   rapidly moving changed particles 

Next Time  Chapter

Summary  Jupiter is the largest planet  Its strong gravity influence the motions of the rest of the solar system  Rotates rapidly and differentially  Explored by Voyager, HST, Galileo, and a comet impact

Summary: Atmosphere  Explored by telescopes, Galileo probe and comet impact  Clouds are composed of ammonia, water and sulfur compounds  Clouds form bands of material moving in opposite directions  Spots and ovals are storms which can occur at different altitudes and can be long lived  Heat from Jupiter’s interior and rotation drives motions

Summary: Jupiter From the Outside In  Satellites: out to ~24 million km  Magnetosphere: out to ~15 million km  Rings: out to ~200,000 km  Atmosphere: out to ~70,000 km  Liquid metallic hydrogen: out to ~50,000 km  Rock/Ice core: out to ~20,000 km