Download Unit Review #2

PHYSICS 127
DESCRIPTIVE ASTRONOMY
Review Sheet #2
The Solar System Plus Exoplanets and Extraterrestrial Life - Key Concepts and Formulae
Sky Familiarity:
Where and when to observe each of the naked-eye planets.
Lunar phase, location and times of moonrise and moonset.
Solar System Overview:
Major components: sun, planets, satellites, rings, asteroids, comets, interplanetary medium, Kuiper belt, Oort cloud.
Terrestrial versus Jovian planets: positions, temperatures, compositions, masses, sizes, rings, satellites, rotational
rates, densities, atmospheres, surfaces, debris.
Common characteristics of all planets: orbital direction, orbital shapes, orbital planes, rotational directions. The
exceptions: Venus, Uranus, Triton, several minor moons.
Major satellites: Ganymede, Titan, Callisto, Io, Moon, Europa, Triton.
Chemical composition: the major constituents.
Formation of the solar system. The solar nebula. Grains, planetesimals, protoplanets and planets. Accretion.
Terrestrial versus Jovian formation. Age of the SS.
Formation of the moon: The collisional ejection hypotheses.
The Earth
The atmospheres: composition, temperature, and clouds. The importance of carbon dioxide and water. The
greenhouse effect. Atmospheric formation and evolution. The roles of volcanic outgassing and cometary impacts.
The surface: plate tectonics, volcanism (hot-spot versus subduction-zone), mountain building, erosion, impact
cratering, icecaps.
The internal structure. The geomagnetic fields: its causes and effects, the aurorae.
The Moon
Surface features, their descriptions causes and histories: maria, highlands, craters, rays, rilles, ridges, grabens.
crater chains, domes and rocks, ice.
Impact cratering versus plate tectonics. Primary versus secondary craters. The order of crater formation.
The absence of an atmosphere.
The interior.
The motion of the moon. Synodic versus sidereal periods. Rotation. Tidal effects on both Earth and Moon.
Mercury
The observational challenge.
The tidally coupled rotation and revolution periods
The surface: similarities and differences among Mercury, Earth and the moon, temperature fluctuations.
The Caloris Basin. Focusing of seismic waves. Ice.
Venus
The atmosphere: similarities and differences between Earth's and Venus' atmospheres, mass and pressure,
composition, temperature, and clouds, carbon dioxide and water. The greenhouse effect. Lightning. Atmospheric
formation and evolution. The roles of volcanic outgassing and cometary impacts.
The surface: comparison with the earth, plate tectonics, volcanism, mountain building, erosion, impact cratering.
The absence of water.
The cores. The magnetic field.
Mars
The atmospheres: similarities and differences among Earth's, Venus' and Mars' atmospheres, mass, pressure,
composition, temperature, clouds, carbon dioxide, water and dust. The greenhouse effect. Atmospheric formation and
evolution. The roles of volcanic outgassing and cometary impacts. The surface: comparison with the Earth and Venus,
plate tectonics, volcanism (hot-spot versus subduction-zone), mountain building, erosion, impact cratering. Martian
jumbled terrain, canyons, and icecaps. Water.
The cores. The magnetic field.
Phobos and Deimos.
Jupiter
Appearance. Oblateness. Composition.
Formation: two-stage accretion.
The atmosphere: composition, bands, zones, ovals, turbulence, color variations and its causes, cyclonic and
anticyclonic circulation, effects of gravity and temperature differences, the great spots of Jupiter, lightning.
The encounter with Comet Shoemaker-Levy.
Moons: Galilean and non-Galilean. Rings.
Radiation excess: its nature and cause.
Internal structure: the density, liquid metal hydrogen.
Jupiter's Galilean Moons
Their relative positions. Surface characteristics.
Similarities, differences and the reasons for.
Tidally coupled rotation. Tidal flexing. Volcanism. Water volcanism.
Saturn
Appearance. Oblateness.
Atmosphere: composition, features and structure.
Rings: ringlets, gaps, shepherds, unexpected and unexplained irregularities, Roche’s limit
Radiation excess: its nature and cause.
Internal structure, the density.
Titan: its appearance, atmosphere, composition.
Mimas, Enceladus, Iapetus, Dione, Rhea, Tethys
The Outer Planets: Uranus and Neptune
Appearances.
Atmosphere: composition, features and structure.
Internal structures.
Rotations: relative rates, the unusual axial orientations of Uranus and Pluto
Satellite systems: formation and acquisition of satellites. The strange moon Miranda. Rings.
The Uranian Moons: Miranda, Ariel, Umbriel, Titania, and Oberon.
The Neptunian moons: Triton: (size, appearance, atmosphere, surface features, retrograde orbit).
Proteus and Nereid
Asteroids, the Kuiper Belt, the Oort Cloud, Comets
Asteroids: Ceres and Vesta. Discovery techniques. The asteroid size distribution. Total asteroid mass. Asteroid
shapes and rotation rates.
Asteroids orbital characteristics: the "asteroid belt", Kirkwood's gaps and the role of Jupiter, Lagrangian points,
Trojan asteroids (Vanguards and Rearguards), Apollo asteroids.
Evidence for asteroid fragmentation. Binary asteroids.
Terrestrial impacts: causes, evidences for, craters, the terrestrial impact rate, impact speeds, iridium deposits and
dinosaur extinction.
Meteoroids, meteors and meteorites: stones, irons and stony-irons; origin of the meteoroids.
The Kuiper belt. Pluto and Eris. The Oort cloud..the Oort cloud.
Cometary structure: the head, nucleus, coma, plasma (ion) tail, dust tail, and hydrogen envelope. The development,
extent and orientation of these components.
Cometary disruption: tidal fragmentation and vaporization. Meteor showers versus sporadic meteors.
Terrestrial accretion of cometary and fine asteroidal materials. The Tunguska event.
The zodiacal light and the gegenschein.
Extraterrestrial Life (as we know it)
The environmental requirements for life, the role of water, the most likely places for life within the solar system
and the reasons that life would be unlikely/impossible in the disqualified sites. The availability of water, carbon,
hydrogen, oxygen and nitrogen. The availability of organic moleculer building blocks. The numbers of suitable
planets.
SETI, the Drake Equation, how we might detect intelligent life at interstellar distances. Suitable and unsuitable
host stars for inhabited planets.