Download STUDY GUIDE – UNIT 3: EARTH IN SPACE

STUDY GUIDE – UNIT 3: EARTH IN SPACE
DAILY APPARENT MOTION/DIAMETER
objects appear to move E to W at 15/hr, due
to Earth’s rotation, sunrise, sunset,
star paths, circumpolar stars, object appears
to get larger or smaller.
larger = closer in orbit, smaller = farther in
orbit
SUN’S PATH
seasonal change in sunrise, sunset, yearly
altitude change, affects length of day,
recognize path for different seasons, shadow
direction and length, opposite, sun never at
zenith in New York, insolation, duration and
intensity of insolation, radiative balance
MOON PHASES / MOTIONS
apparent motion from E to W. correct order /
positioning of phases, seeing same side
rotation = revolution, cycle of phases:
waxing/waning. sidereal month = one
revolution 27 1/3 days, synodic month = one
phases cycle, 29½ days, lunar / solar eclipses,
positioning during phases/eclipses
perigee = closest, largest apogee = farthest,
smallest,
ORBITS / CELESTIAL MODELS
geocentric / heliocentric model, modern
model, slightly eccentric ellipse, eccentricity,
foci, formula e = d/L 0 = perfect circle,
Kepler’s 3 Laws,
1. orbital velocity, KE / PE, faster, closer
2. orbital period, farther = longer revolution,
3. gravitation, closer = greater attraction
EARTH’S ROTATION
rotation rate = 15/hr, CCW, one rotation =
23 hrs, 56 min, 4 sec, rotation rate faster at
equator Focault Pendulum- apparent change in
swing, Coriolis Effect- apparent change in
path of object right in Northern Hemisphere,
left in Southern Hemisphere
TIME AND EARTH MOTIONS
time based on Earth motions, solar noon
when sun reaches maximum altitude, sidereal
day = 23 hrs, 56 min, 4 sec, apparent solar
day = solar noon to solar noon, mean solar day
= clock time determining local solar time, 4
min/degree + or EARTH’S REVOLUTION
Earth orbits the sun, closest to sun =
perihelion, Jan 3rd, farthest from sun =
aphelion, July 4th, revolution = 365 1/4 days,
tilt 23.5, partial cause of seasons, axis
always points towards Polaris
SEASONS / SUN’S PATH
3 reasons: tilt (23 ½) , parallelism (Polaris),
revolution, WINTER: sun at zenith 23½  S,
Tropic of Capricorn, tilted away from sun,
winter solstice = Dec. 21st. short days, long
nights, sun low in sky, sunrise S of E, sunset S
of W, SUMMER: sun at zenith 23 1/2 N,
Tropic of Cancer, tilt toward the sun, summer
solstice = June 21st, long days, short nights,
sun high in sky, sunrise N of E, sunset N of
W, SPRING: sun at zenith at 0, equator ,
vernal equinox = Mar. 21st, equal day/night,
sunrise due E, sunset due W, FALL: sun at
zenith at 0, equator, autumnal equinox =
Sept. 23rd , equal day/night, sunrise due E,
sunset due W
BEYOND EARTH
Universe, light years, galaxies, galaxy shape,
Milky Way, Our sun’s characteristics: size,
temp, average, rotation, sunspots, solar
system, Terrestrial vs. Jovian, comets,
asteroids, meteors, origin of our universe (big
bang), stars’ life cycle, nebula, main sequence,
red giant, H-R diagram