| solareclipse | | phases of the moon are caused by this |
| whitedwarf | | developed the heliocentric model of the solar system |
| heliocentric | | a dying star that is slowly cooling off |
| moon | | the sudden brightening of a white dwarf |
| geocentric | | tool used for observing the sky |
| nebula | | the study of the universe |
| satellite | | an expanding shell of gas; stellar nursery |
| galaxy | | occurs when the moon passes into the shadow of the earth |
| winter | | Hubble announced that the universe was doing this |
| universe | | a rare event involving the explosion of a star |
| steadystateuniverse | | our seasons are caused by this movement of the earth |
| elliptical | | stars are composed of ____ and helium gases |
| milkyway | | this diagram is used to classify stars |
| hydrogen | | theory that the universe began with all matter and energy concentrated in a very small object |
| sunlight | | a vehicle that is intended to carry humans into space |
| spacecraft | | consists of all matter, energy and space |
| lunareclipse | | the sun gets its energy through this process |
| oscillatinguniversetheory | | an object launched into orbit; could be used with GPS |
| kepler | | large groups of stars clustered together |
| newton | | developed the 3 models of planetary motion |
| nova | | a cool giant star |
| copernicus | | type of galaxy we live in |
| blackdwarf | | theory that states the universe is undergoing cycles of expansion and contraction |
| nuclearfusion | | distance light travels in one year |
| different | | occurs when the moons shadow falls on the earth |
| astronomy | | type of galaxy with little dust and gas |
| lightyear | | explained how gravity keeps the planets in order |
| supernova | | different hemispheres have _____ seasons |
| rotation | | developed the geocentric model of the solar system |
| spaceprobe | | the final stage of a white dwarf |
| bigbangtheory | | night and day are caused by this movement of the earth |
| spiral | | model of the solar system that we accept today (sun centered) |
| telescope | | spacecraft that carries instuments to explore space |
| revolution | | when it is summer in the southern hemisphere, it is ____ in the northern hemisphere |
| redgiant | | theory that states there never was a beginning and there will not be an end to the universe |
| aristotle | | a complete cycle of the ____ takes about 29.5 days |
| hertzsprung-russell | | name of the galaxy we live in |
| expanding | | the model of the solar system that said it is earth centered |
