Jupiter and its Moons Lab 4 Jupiter 5

Jupiter and its Moons Lab 4

Jupiter • 5 th planet from the Sun • largest one in the solar system • if Jupiter were hollow, more than one thousand Earths could fit inside • contains more matter than all of the other planets combined • mass of 1. 9 x 1027 kg • 28 known satellites, 4 of which (Callisto, Europa, Ganymede and Io) were observed by Galileo in 1610 • there is a ring system, but it is very faint • Jupiter radiates more energy into space than it receives from the Sun. Its core is ~ 20, 000˚ K.

Mythology associated • Jupiter (Zeus) was the King of the Gods, the ruler of Olympus and the patron of the Roman state. Zeus was the son of Cronus (Saturn). • Europa is named after the beautiful Phoenician princess who, according to Greek mythology, Zeus saw gathering flowers and immediately fell in love with. Zeus transformed himself into a white bull and carried Europa away to the island of Crete. He then revealed his true identity and Europa became the first queen of Crete. Zeus later re-created the shape of the white bull in the stars which is now known as the constellation Taurus.

Jupiter • composed of 90% hydrogen and 10% helium, with small amounts of CH 4, NH 3, H 2 O vapor and other compounds • At great depths within Jupiter, the pressure is so great the hydrogen atoms are broken up, freeing the electrons so that the resulting atoms consist of bare protons. This produces a state in which the hydrogen becomes metallic • dynamic weather systems illustrated by colorful latitudinal bands, atmospheric clouds and storms • cloud patterns change within hours or days • The Great Red Spot is a complex storm moving in a counter-clockwise direction. At the outer edge, material appears to rotate in four to six days; near the center, motions are small and nearly random in direction

Jupiter animation • http: //www. solarviews. com/raw/jup/vjupitr 5. mpg

Internal Structure of Jupiter • The outer layer is primarily composed of molecular hydrogen • At greater depths the hydrogen starts resembling a liquid • At 10, 000 kilometers below Jupiter's cloud top liquid hydrogen reaches a pressure of 1, 000 bar with a temperature of 6, 000° K. • At this state hydrogen changes into a phase of liquid metallic hydrogen. In this state, the hydrogen atoms break down yielding ionized protons and electrons similar to the Sun's interior. • Below this is a layer dominated by ice where "ice" denotes a soupy liquid mixture of water, methane, and ammonia under high temperatures and pressures • Finally at the center is a rocky or rocky-ice core of up to 10 Earth masses

The Galilean Moons

Ganymede • largest moon of Jupiter and is the largest in our solar system with a diameter of 5, 262 km (3, 280 miles) • composed of a rocky core with a water/ice mantle and a crust of rock and ice • no known atmosphere, but presence of ozone means a thin tenuous oxygen atmosphere from charged particles disrupting surface ice • http: //www. solarviews. com/raw/jup/vgany 2. mpg

Callisto • 2 nd largest moon of Jupiter, 3 rd largest in the solar system, ~same size as Mercury • orbits just beyond Jupiter's main radiation belt • Callisto is the most heavily cratered satellite in the solar system • Its crust is very ancient and dates back 4 x 109 years • Callisto has the lowest density (1. 86 gm/cm 3) of the Galilean • appears to be composed of a crust 200 km thick • Beneath the crust is a possible salty ocean ~10 km thick • Beneath the ocean, is an unusual interior composed of compressed rock and ice with the percentage of rock increasing as depth increases • Callisto, like Ganymede, has no known atmosphere

Callisto animation • http: //www. solarviews. com/raw/jup/vcallis 1. mpg

Europa • crust composed of water and ice • surface is among the brightest and smoothest in the solar system • Lines and cracks wrap the exterior as if a child had scribbled around it. • Europa may be internally active, and its crust may have, or had in the past, liquid water which can harbor life • http: //www. solarviews. com/raw/jup/veuropa 1. mp g

Io • most volcanic body known, with lava flows, lava lakes, and giant calderas covering its sulfurous landscape • billowing volcanic geysers spewing sulfurous plumes 500 km high • Its mountains are much taller than those on Earth reaching heights of 16 km (52, 000 feet) • Io appears to be a rocky silicate rich body that has a dense Fe/Fe. S core that extends halfway to the surface with a partially melted silicate-rich mantle, and a thin rocky crust. • http: //www. solarviews. com/raw/jup/vio 1. mpg

Internal Structure of Io

Very Exotic • Io orbits very close to Jupiter's cloud tops, placing it within an intense radiation belt that bathes the satellite with energetic electrons, protons, and heavier ions • As the Jovian magnetosphere rotates, it sweeps past Io and strips away ~1, 000 kg (1 ton)/sec of volcanic gases • This produces a neutral cloud of atoms orbiting with Io as well as a huge, doughnut shaped torus of ions that glow in the ultraviolet. • Io acts as an electrical generator as it moves through Jupiter's magnetic field, developing 400, 000 volts across its diameter and generating an electric current of 3 x 106 amperes that flows along the magnetic field to the planet's ionosphere

Using Kepler’s 3 rd Law • MJupiter = a 3/P 2 where M=mass of Jupiter in solar masses, a=radius of its moon’s orbit in AU, and P=period of its moon’s orbit in years

Converting to Keplerian Units • If P=5 days, then 5/365 = 0. 014 years • If a = 3. 5 JD, where JD is diameter of Jupiter, then 3. 5 JD/(1050 JD/AU)=0. 0033 AU