Jupiter View from Earth Jupiter is the fourthbrightest

Jupiter

View from Earth ¡ ¡ Jupiter is the fourth-brightest object in the night sky Jupiter is brightest when it is near opposition Photograph taken with a ground based telescope, Hubble Space Telescope several of the moons are visible image taken during opposition in 1990

Mass and Radius ¡ 318 Earth masses l l ¡ Jupiter has more than twice the mass of all the other planets combined As massive as Jupiter is, it is still only a thousandth the mass of the Sun 11. 2 Earth radii l More than 1400 Earths would be needed to equal the volume of Jupiter

Rotation ¡ ¡ The equatorial zones rotate a little faster than the higher latitudes Jupiter has differential rotation l The rotation rate is not constant from one location to another A rotation period of 9 h 55 m is fast for such a large object Jupiter has the fastest rotation rate of any planet in the solar system, and this rapid spin has altered Jupiter’s shape All spinning objects tend to develop an equatorial bulge because rotation causes matter to push outward against the inward-pulling gravity

Atmosphere ¡ ¡ Hydrogen-86. 1% Helium-13. 8% Small amounts of atmospheric methane, ammonia, and water vapor are also found Jupiter has a banded appearance of bright zones and dark belts l l l Appear to be the result of dynamic motion in the planet’s atmosphere Zones-higher pressure Belts-lower pressure ¡ ¡ Belts and zones are Jupiter’s equivalents of the familiar high- and low-pressure systems that cause our weather on Earth Jupiter’s rapid rotation has caused these systems to wrap all the way around the planet

Jupiter’s Convection Upwelling warm gas results in the lighter-colored zones; the darker bands overlie lower-pressure regions where cooler gas sinks back down into the atmosphere. As on Earth, surface winds tend to blow from high- to low-pressure regions. Jupiter’s rotation channels these winds into an east–west flow pattern Zonal Flow The wind speed in Jupiter’s atmosphere, measured relative to the planet’s internal rotation rate. Alternations in wind direction are associated with the atmospheric band structure.

Atmosphere ¡ Jupiter’s clouds are arranged in three main layers l l l The white regions are the tops of the upper ammonia clouds The yellows, reds, and browns are associated with the second cloud layer, which is composed of ammonium hydrosulfide ice The lowest cloud layer is water ice and bluish in color

Core ¡ ¡ ¡ Careful calculations indicate that Jupiter would be more flattened than it actually is if its core were composed of hydrogen and helium alone To account for the planet’s observed shape, we must assume that Jupiter has a dense, compact core 10 times Earth’s mass May be a dense, hot liquid with a consistency like thick soup The pressure inside may be 30 million times greater than the pressure at Earth’s surface

Magnetosphere ¡ ¡ Jupiter is surrounded by a vast sea of energetic charged particles The radiation is several thousand times more intense than that produced by Earth’s magnetic field l ¡ ¡ The particles are a potentially serious hazard for space vehicles Direct spacecraft measurements show Jupiter’s magnetosphere to be almost 30 million km across, roughly a million times more voluminous than Earth’s magnetosphere The size and shape of Jupiter’s magnetosphere is determined by the interaction between the planet’s magnetic field and the solar wind l Jupiter’s magnetosphere has a long tail extending away from the Sun at least as far as Saturn’s orbit

Moons ¡ ¡ ¡ Jupiter has at least 63 known moons Most of the outer moons are probably asteroids captured by Jupiter’s gravity Galilean Moons l l l First seen in 1610 by the astronomer Galileo Galilei Four largest moons Named after the mythical attendants of the Roman god Jupiter

Galilean Moons Moving outward from Jupiter, the four are named Io, Europa, Ganymede, and Callisto ¡ Range in size from slightly smaller than Earth’s Moon to slightly larger than Mercury ¡

Io The densest of the Galilean moons ¡ The most geologically active object in the entire solar system ¡ Has active volcanoes ¡

Europa ¡ Might be completely covered by an ocean of liquid water whose top is frozen at the low temperatures prevailing so far from the Sun

Ganymede and Callisto Ganymede is the largest moon in the solar system and has its own magnetic field ¡ Callisto may have icy oceans beneath the crust ¡

Rings ¡ ¡ ¡ Made up of dark fragments of rock and dust Possibly chipped off the innermost moons by meteorites Were unknown before the two Voyager spacecraft arrived at the planet ¡ There are three parts to Jupiter's rings l l l The innermost, cloudlike ring is called the Halo Ring The next one out is the Main Ring, which is quite narrow and thin Beyond the Main Ring is the wispy, nearly transparent Gossamer Ring

Galileo ¡ ¡ ¡ NASA’s Galileo dropped a probe into the atmosphere of Jupiter The probe carried 6 instruments and survived the crushing pressure and heat for nearly 1 hour Collected the first real data about the chemistry of a gas planet After the release of the probe, it began a multi year orbit of Jupiter Galileo deliberately plunged into Jupiter's crushing atmosphere on Sept. 21, 2003

Jupiter video ¡ Quiz to follow

QUIZ

#1 ¡ The four largest moons of Jupiter were first observed by _____. A. B. C. D. Kepler Galileo Ptolemy Copernicus

#2 ¡ For Jupiter to make one orbit around the sun, it takes about _____ years. A. B. C. D. 6 9 12 15

#3 ¡ What is Jupiter mainly composed of? A. B. C. D. helium oxygen nitrogen hydrogen

#4 ¡ Jupiters Great Red Spot is a giant crater. l l true false

#5 ¡ Jupiters atmosphere contains _____. A. B. C. D. radon chlorine methane ammonia

#6 ¡ The Io torus, a doughnut of electrically charged particles around Jupiter, is produced by the action of Jupiter’s _____ on the moon, Io. A. B. C. D. magnetic field gamma radiation gravitational field atmospheric gases

#7 ¡ Io’s surface has no craters because of continual _____. A. B. C. D. wind erosion volcanic activity tectonic shifting water condensation

#8 ¡ Which is Jupiter’s biggest moon? A. B. C. D. Io Europa Callisto Ganymede

#9 ¡ Scientists think that Europas crust is mostly made of _____. A. B. C. D. ice lava sulfur carbon

# 10 ¡ The Jupiter Icy Moons Orbiter is expected to visit three of Jupiters moons and to look for signs of oceans. l l true false

Answers