Download Study Guide-Space Unit

Study Guide - Astronomy (Test: Friday, February 22, 2013)
Vocabulary:
 Solar system: sun is center, 8 planets orbit around the sun (+Pluto)
 Orbit: a path that one object follows around another
 Rotate (rotation): spinning on an axis
 Axis: the imaginary pole that the earth spins on
 Revolve (1 trip = 1 revolution): moving in a circular path around another
Moon: revolves around earth (takes 28 days) about 1 month
Dark side of the moon: moon does not rotate, same side always facing planet Earth.
Made of solid matter. Moon reflects sunlight; different phase shapes result of moon’s position in
orbital path around planet Earth.
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Phases of the moon: the changing view of the moon (must recognize all phases below)
New moon: the beginning of the phases, we don’t see any of the lighted up side.
Crescent moon (classic Dreamworks shape),
First quarter (half),
Full moon,
Third quarter (half),
Crescent moon…then New moon again
Review words that may apply:
 Gravity: the force that pulls objects together
o All objects with mass have gravity; more mass = more gravity
o Mass – the amount of stuff (matter) in an object
o As distance increases, pull of gravity decreases. (Example: astronauts floating in the
International Space Station)
 Equator: the imaginary line that splits the northern and southern hemisphere
 Hemisphere: two halves of the earth
Things in the solar system:
planets, moons, earth, space junk, comets and asteroids
seasons: created by earth’s tilt on its axis. It is warmer in the summer because the Earth is
receiving direct sunlight, versus indirect. (North America is facing the sun in the summertime)
day and night: created by rotation on axis
*seasons, day/night, and moon phases all follow cycles or patterns that repeat.
24 hours = 1 day (rotation)
365 ¼ days = 1 year (1 revolution of earth around the sun)
28 days = 1 lunar month (there are 13 in a year)
Leap Year = 366 days (extra day to account for ¼ day over 4 year period)
Sun: sun is the center of the solar system - most massive object in solar system so it has the
strongest gravitational pull, that is why all planets revolve around it.
Made of burning gases; Considered a medium sized star; Looks so big because it is so close.
*Earth stays in orbit because of revolution (sideways speed) and sun’s gravitational pull
Constellations change throughout the year depending on Earth’s position in its orbital path.