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Jupiter Facts

History of Discovery & General Info

Known since ancient times Largest in solar system by far

o 318 times as massive as Eartho 11 times diameter of Earth

5th planet from the sun First of the Jovian planets (gas giants)Mythology

Roman god of the sky, ruler of pantheon Greek equivalent: ZeusOrbital Characteristics

Semi-major axis 5.20 AU

Aphelion 5.46 AU

Perihelion 4.95 AU

Orbital period4332.59 days

(11.9 Earth years)

Jupiter Day 9h 56m

Eccentricity 0.048775

Orbital inclination 1.304 degrees

Groups of asteroids gather at Lagrange pointso Asteroids preceding Jupiter named for

Greeks

o Asteroids after named for Trojans Jupiter protects Earth from many incoming

asteroids/comets

o Also occasionally deflects them at usSurface Geology

No crust, just a core Mostly heavy elements like iron and silicon Temperature = 13000-35000K Pressure = ~100 billion pascals

Gas turns to liquid at 85% of radius Ocean of liquid H and He surrounds core

Atmospheric Composition

Hydrogen and Helium Small amounts of water vapor and ice

Differential rotation About six different jet streams per

hemisphere

Wind speeds up to 150 m/s (540 kph) Clouds of ammonia ice Varying dry and wet zones Massive storms with lightning superboltsGreat Red Spot

Red cloud of gas 2 to 3 times Earths size 26 million meters by 134 million meters 20 to 40 kilometers deep

Couterclockwise rotation Southern hemisphere High pressure anticyclone

Long-lived: 150-300 years No landmass to dissipate storm energy Recently has begun to shrink

Little Red Spot

Smaller cousin to Great Red Spot Growing while GRS is shrinking Also anticyclonic Highest wind speed of any location on record =

~618 kph

Rings

Halo (100-122.8 megameters) Main (122.8-129.2 megameters) Gossamer (129.2-214.2 megameters)

Two parts

Composed mainly of dust Moons orbiting inside rings may cause this

Adastria and Metis in Main Amalthea and Thebe in Gossamer

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Moons

67+ moons Galilean Moons (in order of distance from

Jupiter): Io, Europa, Ganymede, Callisto

Discovered by Galileo in 1610 Evidence that not all bodies orbit the Earth Four largest Jovian moons Others are no bigger than 10% diameter

1. Io 100 volcanoes Releases charged particles Heated by flexing

Gravitational forces from other moons causea distorted orbit and therefore uneven tidal

forces. This causes friction which producesinternal heat.

Sulfur is abundant Frozen sulfur dioxide Sulfur dioxide in the atmosphere Makes the surface orange and covered with

strange formations

2. Europa High albedo

Smooth surface is likely icy Heated internally

Maybe radioactivity More likely tidal flexing

Promising possibility for life3. Ganymede Named for Jupiters cupbearer Largest moon in the solar system

bigger than Mercury

Has its own magnetic field Rocky core Water ice on surface is cold enough to be

extremely hard

Lots of impact craters Crater impacts in ice create weird, grooved

terrain

Faults like those on Earth

4. Callisto Old and very pockmarked Valhalla impact crater

Bulls-eye with 10 ringsMagnetic Field 10x as strong as Earths at cloud height

Inner field (donut) = shells of particles Outer field (pancake)

Interacts with solar wind Gets squished by incoming particles Emits radio waves Creates huge auroras

Major Missions

1970s: (Fly-bys)o Pioneer 10 & 11o Voyager 1 & 2

1992: Ulysseso Took data on magnetosphereo Used a swing-by to go into a highly-

inclined orbit

1995-2003: Galileoo Orbited Jupitero Moon fly-byso Sent down an atmospheric probeo Crashed into Jupiter in a controlled

impact

2000: Cassinio Took detailed pictures

2004: Ulysses passes again 2006: New Horizons passes by

o It needed a gravity boost going to Pluto 2016: Juno

o Named for Jupiters wifeo Launched in 2011o Will be the 2nd orbitero Will see through thick cloud cover

2030: JUICEo JUpiter ICy moon Explorero Planned for 2022 launcho Will orbit Jupiter and then Ganymede