Unit 4 study guide
• Discovery of Ceres:
o Asteroid:rocky 100m to couple km
o Meteoroid: rocky mm to 100m
o Meteor:the light phenomenon produced by small meteoroid
o Meteorite:fragments of meteoroids landed on Earth
o Fireball: light phenomenon produced by large meteoroid
• The Titius-Bode Law/Rule
o You need to remember the basic math: a series of the consecutitive number is doubled of the
previous one: 0, 3, 6, 12..add 4 divided by 10=predicted AU of planet’s orbital distance
• Main Asteroid Belt o Location: Gap between Mars and Jupiter, where most of asteroids lie
o Influence of Jupiter: Formerly uniformly distributed in inner system, as planets formed, asteroids
were kicked out to be around Jupiter, same time as Uranus and Neptune was kicked out. Enormous
mass has profound gravitational effect on bodies surrounding it
• Why the gaps: Kirkwood gaps=Jupiter’s orbit, but fractions. Where asteroids can escape the
belt. o Classification: C-type, S-type E-type and M-type, carbon, silicate, metal with high albedo and
metallic. Carbon 75% silicate 15%
• How do we get the composition: comparing albedo and spectrum (o dark, 1 reflecting)
• Does the distribution of asteroid types match distribution of meteorite types collected on
Earth: despite their consistency in spectrum from samples of meteorites matching the asteroid,
the large amount of S-type on Earth does not match the distribution of S-type in space
• Note location of most C-rich: middle to outer edge of the belt
• Families: asteroids with same orbital feature, Hirayama families
• Non-Belt Asteroids
o NEAs and NEOs:Near earth objects and near-earth asteroids
• Atens: within Earth’s orbit. Apollos: earth orbit crossing Amor:mars crossing but not earth
o Trojans: trap for small bodies, along Jupiter’s orbit
o PHAs: potentially hazardous asteroids, diameter>150m, less than 0.5 AU
• Impact risk and the Torino Scale: impact risk assessing asteroids/comet impact predictions. 0
to 8-10 (certain collision), Apophis: large asteroid of 4 to 0. No immediate danger of any
asteroids in 21th century.
• Asteroid exploration o Eros and Itokawa:NEAR shoemaker softly landed and studied NEA Eros. Main belt Mathilde
flyby by NEAR, with an interestingly low density. Gaspa, main belt, visited by Gailleo, fist to have
HD pictures. Itokawa, first sample came back from asteroid.
o Fall vs. Find: find, you literally have no idea when it got there and found it. Fall is when you knew
it has entered the earth.
o Stones or aerolites: iron, stone-irons, stones. Siderite, siderolites, aerolites.
• Chondrites and chondrules: chondrites have chondrules, accretion, process of forming
protoplanets. Chondrules condensed from hot cloud in early solar nebula, contained Organic
matter. Building blocks for life are brought by meteors.
• Achondrites: molten rock crystallized (igneous), residues from melting, residue rock. Asteroids
get hit, chunk falls off, igneous rock is achondrites. Residue is primitive achondrite.
o Stony-irons or siderolites
o Irons or siderites
• Learn how they likely formed and what they represent to interactions with atmosphere: atmosphere reduces
meteor’s momentum thus creating drag through ablation, the energy is release as light. • Meteors: 2 sources: asteroid collision and comets. When we cross comet’s orbit and comets
melted in the atmosphere, leave trail of dust behind called “meteor shower”.
• Dust to sand size: mm/100 diameter
• Meteor showers associated with comet tails (you need not memorize which is which except for the
Leonids and Temple-Tuttle) :Temple shuttle left lenoids shower of 200,000+ meteors.
o Fireballs: most meteor never reached Earth’s surface, until it reached 95 to 145km, air became dense, kinetic
energy->heat, melting surface (ablation), atmospheric gas reduced to produce light.
• The big ones:
• Kinetic energy equation: know it! Inertia, resistance to change in its motion, momentum=mass
and velocity. E=1/2mv^2, energy proportional to squares of velocity.
o Regmaglypts and fusion crusts: depression of meteorites like thumbprints- Regmaaglypts.
Fusion crust: layer of glass on top due to melting.
• Principal tools of investigation: petrographic microscope, mineral’s optical properties, textual.
Electron microscope: use electrons to tell compositions. Mass spectrometer: measures
radioactive isotope decays. Age of the sample
Finder’s keepers in Canada, meteorites fell location determines ownership in U.S.
Unit 5 Study Guide
• What defines a gas/ice giant? •Ice giant-methane, ammonia, water. Gas giant-hydrogen and helium
• Origin in the solar system
• Collision of Shoemaker-Levy 9 with Jupiter
○ Just the generalities: pulled into 21+ pieces by Jupiter, impacted the planets with
mega tons of TNT like energy for six days. Impact is used as probes to improvise on
the existing theory of Jupiter’s atmosphere, evidence to be large comet impacts for
Chapter 14: Jupiter
•General planetary properties
•Green-red spot, vortex over Jupiter.
○ Distance from Sun: 5.3 AU
○ Density: 1.326 g/cc
○ Fast rotation: 10 hours.
○ “Upright” inclination
○ Has satellites and rings: 63: IO- most volcanic acive body in solar system. Europa:
water under its ice surface. Ganymade water ocean under ice cover. Callisto is a body
that apparently never chemically differentiated.
•Missions ○ By far most important: Galileo: only craft to orbit Jupiter, in space for 14 years and
orbiting for 8 years, purposefully destroyed to protect Europa so it wouldn’t crush
into it in the future. Changed the way we think Solar system
○ New Horizons just gone by: Crossed Uranus at 2008 with flybys Jupiter
○ Can tell Jupiter has a rocky core by: heat flow, density calculation
•Emits 1.7 times as much as energy it received from sun. Hydrogen to liquid H then
metallic H then heavy metal core, density calculated by influenced of passing
spacecraft divided by volume.
Enormous dynamo effect (two states of hydrogen interacting) to mage impressive
magnetosphere (reaches as far as Saturn); high content of radiation trapped by the