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Space
vocabulary
Term | Definition |
---|---|
universe | all the galaxies, matter, and energy |
galaxy | group of billions of stars and their planets, gas, and dust |
Milky Way | the galaxy our solar system belongs to |
solar system | the sun, planets, dwarf planets, moons, asteroids, comets, and meteors |
revolution | the movement (orbit) around another object |
rotation | the spinning motion of an object on its axis |
gravity | the pulling force between two objects |
hydrogen and helium | the gases that make up the sun |
nuclear fusion | the process by which 2 hydrogen atoms fuse to make helium |
sun spots | dark areas on the sun |
prominences | loops of gases that link sunspots |
solar flares | an explosion of gases on the sun. Cause communication problems on earth |
planet order | Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune |
astronomical unit (AU) | average distance of Earth to the sun is one AU |
phases | one of the different shapes of the moon as seen fromEarth |
waxing | growing larger |
waning | growing smaller |
spring tide | when the Earth, moon, and sun are allined and very high or very low tides occur |
neap tide | lower tides occur because the sun and moon are not alligned |
geocentric | the early belief that Earth was the center of the solar system and all the planets revolve around Earth |
astronomer | scientist who studies the solar system and beyond Earth |
Ptolemy | believed in geocentric theory |
Aristotle | believed in geocentric theory |
heliocentric | a theory of the solar system in which all planets revolve around the sun |
comet | a ball of ice and dust that orbits the sun in a long ellipse |
asteroid | rocky objects that revolve around the sun, too small to be planets |
meteoroids | chunks of rock or dust in space |
meteor | a meteoroid that burns up as it seems to streak across the night sky |
meteorites | meteoroids that hit Earth and leave craters |
USSR | the country the US competed with to control space in the 1950s and 1960s |