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astronomy
science
Term | Definition |
---|---|
astronomy | the study of all physical objects beyond earth |
astronomer | someone who studies space/heavens |
revolution | the elliptical motion of a body as it orbits another body in space |
rotation | the spinning motion of a body on its axis |
orbit | the elliptical path a body takes as it travels around another body; the motion itself |
calendar/gregorian | a system for organizing time |
year | the time required for the earth to orbit the sun once |
month | the time required for the moon to orbit the earth once |
day | the time required for the earth to rotate once on its axis |
heliocentric | sun centered |
geocentric | earth centered |
astrolabe | handheld tool invented by the arabs used to measure the stars |
horizon | the line where the sky and earth appear to meet |
zenith | an imaginary point in the sky directly above an observer on earth |
altitude | the angle between the object and the horizon |
azimuth | imaginary circle that forms exactly around the horizon at 360 degrees |
celestial sphere | stars in a sphere shape around earth |
declination | a measure of how far north or south an object is from the celestial equator |
right ascension | measure of how far east an object is from the point at which the sun appears on the first day of spring |
telescope | instrument that collects electromagnetic radiation from the sky and concentrates it for better observation |
optical telescope | telescope that collects visible light for closer observation |
electromagnetic radiation | radiation from the sun |
star maps | circular maps the marked stars by hemisphere |
astronomical unit | way to measure units to planets (sun to planet) |
light year | distance light travels in a year (6 trillion miles/year) |
big bag theory | the theory that states the universe began with a tremendous explosion |
nebula | a large cloud of dust and gas in interstellar space (where stars are formed) |
solar system | the system composed of the sun and the planets and other bodies that travel around the sun |
galaxy | a large grouping of stars in space |
star | huge, hot, brilliant balls of fire |
planet | celestial body that orbits a star |
moon | natural satellite |
asteroid | small, rocky body that revolves around the sun |
meteoroid | small, rocky body orbiting the sun |
meteorite | meteoroid that strikes earths ground |
meteor | when meteoroid moving towards earth at a fast pace and light comes off of it |
fusion | energy from a star |
satellite | a natural or artificial body that revolves around a planet |
space probe | a vehicle that carries scientific instruments to planets or other bodies in space |
comet | planetesimals made of ice, 'dirty snowballs' |
seasons | 4 divisions, weather patterns/daylight hours |
tilt | cause to move into a sloping position |
planetesimals | the tiny building blocks of the planets that formed as dust particles stuck together and grew in size |