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Astronomy
Things and People to Know
Term | Definition |
---|---|
Rotation | the spinning of Earth on its axis |
Galaxy | a huge cluster of stars, dust and gas held together by gravity |
Venus | this terrestrial planet has a thick, poisonous atmosphere and is often referred to as Earth's twin. |
Copernicus | this astronomer was the first to develop the heliocentric model of our solar system |
Ring | the gas giants all have at least one of these, which is a disk of small particles of ice and rock |
Sun | the star at the center of our solar system; also the ONLY star in our solar system |
Revolution | the movement of one planet around another; also known as a planet's orbit |
Saturn | the gas giant with the most complex ring system |
Uranus | this gas giant's axis is tilted, causing it to spin on its side |
Terrestrial | Mercury, Venus, Earth and Mars are described this way because they are made of rock |
Mars | this terrestrial planet is also known as the "Red Planet" and is believed to have once had water |
Kepler | this astronomer was Brahe's assistant and used information they gathered to study the the planets' orbits; he was the first to propose that they were shaped like a flattened circle, or ellipse |
Tycho Brahe | this astronomer first described the the positions of our planets in the solar system |
Moon | a natural satellite that revolves around a planet |
Galileo | astronomer who used the telescope to make discoveries that supported the heliocentric model of the solar system |
Ptolemy | the Greek astronomer who first explained the Geocentric Model of the universe |
Pluto | is now known as a "Dwarf Planet" |
Neptune | a cold, blue planet in our solar system |
Elliptical | the shape of the planets' orbits: oval shaped |
Geocentric Model | this model states that the Earth is at the center of the solar system and that everything else revolves around it |
Eight | the number of planets in our solar system |
Heliocentric Model | the current theory of the organization of our universe; states that the Earth is part of a solar system that revolves around the sun |
Gas Giants | Jupiter, Saturn, Uranus and Neptune are said to __ ___ because of their size and composition |
Jupiter | the largest planet in our solar system; has a giant hurricane system the size of Earth |
Mercury | this small terrestrial planet has almost no atmosphere & was first explored by the Mariner 10 |