Astro_1040_StudyGuide1

Astronomy 1040 Study Guide for Midterm #1

I. Essentials for understanding astronomy
    what is a theory? Examples from astronomy
    astronomical distances: powers-of-ten notation
    units: the AU, the light-year (ly), the parsec (pc) (no calculations)
    astronomer's almanac

1. Discovering the night sky
    constellations: seasonal patterns
    features of the celestial sphere
    Earth's rotation: sidereal and solar "days"
    latitude-longitude-time zones

    Earth's revolution: length of the "year"
    leap years and calendars
    seasons: equinoxes and solstices; changing light levels and day lengths
    the analemma
    ecliptic: a word with several meanings
    zodiac: 13 constellations
    precession

    lunar notions
    phases
    sidereal and synodic months

    eclipses: moon must be where its orbits intersects the ecliptic (a node)
    lunar: total, partial, penumbral
    solar: total, annular, partial
    eclipse "seasons"

2. Gravitation and the "waltz of the planets"
(use your class notes as well as the text)
pre-Greek astronomy

    what the Greeks knew
    the challenge of explaining retrograde motion of planets
    geocentric vs heliocentric cosmology
    searching for parallax of stars

    Aristotle
    Aristarchus
    Eratosthenes
    Hipparchus
    Ptolemy

    Renaissance astronomy
    Copernicus
    Tycho Brahe
    Kepler
    Galileo
    Newton (limited to brief class notes)

Astronomy 1040 Study Guide for Midterm #2 (the Solar System)

This section has been a tour of the bodies of the solar system (planets, moons, asteroids, comets) plus an overview of the origin of the system. We have examined the physical and orbital characteristics of each planet, the atmospheres and surfaces (where they existed) and what we know of the interior of each planet. We have looked at the major satellites, most of which occur in the outer solar system, and have seen that some “moons” are larger than some “planets”. Throughout, we have found evidence that impact cratering is one of the most important processes which have shaped the planets (everything from forming scars of all sizes on the solid surfaces to bringing water to the inner solar system). We have also learned something of the discoveries of the outer three planets, beginning with Herschel’s accidental discovery of Uranus. Today’s view of the solar system has been made possible by information from Mariner, Magellan, Viking, Voyager, and by more recent missions like the Galileo spacecraft at Jupiter.

Terrestrial planets:

general characteristics
stages in the evolution of the terrestrials

accretion and crustal formation

basin formation

filling of the basins

continued slow surface evolution

atmospheres of the terrestrials

temperature, mass of the planet, and composition of the atmosphere

nature/activity of the surface

mass (and amount of heat remaining within the planet)

Earth

age and internal structure
the lithosphere and plate tectonics
evolution of the oceans and the atmosphere
evidence and implications of cratering

Luna

phases and rotation / synchronous rotation and the tides
nature of the surface: dust, lunar “mountains”, craters!
the Apollo missions and the lunar rocks: what has been learned
the Big Impact theory (and evidence)
evolution of the lunar surface

Venus

retrograde rotation
the thick carbon dioxide atmosphere: runaway greenhouse warming
surface photos and radar maps
craters, volcanoes (pancake domes, shields, etc), coronae

Mercury

2/3 spin orbit resonance: neither the hottest nor the coldest planet!
cratered surface--in some ways like the moon
appears to be a planet made mostly of a metal-rich core

Mars

Lowell and early observations: canals?
similarities with Earth
the thin carbon dioxide atmosphere and Mars’ climate
rocks and soil and frost: the Viking missions of l976
evidence for water on or below the surface: early Mars with a thicker atmosphere and warmer surface
the Martian meteorite

Asteroids

rocky and metallic planetesimals mostly between Mars and Jupiter
most meteorites come from the asteroid belt
several asteroids have orbits which cross Earth’s orbit

Jovian Planets

general characteristics
compositions in the outer solar system: ice and rocky material, along with H + He
magnetic fields
satellite systems! rings!

Jupiter and Saturn

banded atmospheres
rings and moonlets
Galilean satellites: Io, Europa, Ganymede and Callisto
volcanism, an ocean(?), tectonics, cratering
Titan at Saturn: an atmosphere like Earth’s early one?

Uranus and Neptune

Herschel’s discovery of Uranus in 1781
the discovery of Neptune by Adams and Leverrier (1846)
atmospheres, magnetic fields, ring systems, and interiors
Uranus’ axial tilt and odd seasons
Miranda at Uranus: a very odd surface
Triton at Neptune: volcanism and geysirs

Pluto-Charon

is Pluto really a planet?
the painstaking discovery by Tombaugh in 1929-30
its very small mass and other unusual characteristics
the search for planet “X”

Comets

reservoirs: the Oort cloud and the Kuiper belt
comet orbits and behavior
composition and origin
comet lore and role in history
“meteor showers” occur when Earth passes through comet paths: dust grains burn up in the atmosphere

Origin of the Solar System

things which should be explained by any theory of formation:
review the characteristics of terrestrial and Jovian planets, including composition, orbital motions (mostly in or near the ecliptic and in the same direction), rotation in the same direction as revolution (with some exceptions) and spacing of the orbits (the Titus-Bode rule).
the protosun
contraction of the solar nebula
planetesimals and protoplanets
condensation of dust and formation of the terrestrials
condensation of ices and formation of the Jovians
remaining debris: impacts

Note: test will be multiple-choice, with several diagrams included.