Astronomy DSST Practice Questions and Answers

heliocentric theory places the sun at the CENTER of the solar system, states that all other bodies in the solar system orbit it. This was in direct contradiction to Ptolemy's geocentric theory, that stated the earth was the center of the universe Nicolaus Copernicus widely credited as the father of the heliocentric theory (sun is the center of the universe) he was not the first to propose the concept but his mathematical model was the first that correctly predicted the movement of the planets. Later he published a book that made the idea popular. Hans Lippershey usually credited as the inventor of the telescope (though it wasn't called that at first) he was a German-dutch lens maker who first applied for the patent of the "dutch perspective glass" it is important to note that, at the time, these were not used for astronomy until GALILEO Galileo Galilei the first to use the telescope for astronomical studies. Used the telescope to discover the four largest moons of Jupiter. Galileo was a firm believer in the heliocentric theory. Since most scientists of the time and (more importantly) the church embraced the geocentric theory, this caused Galileo much trouble and is why he was placed under house arrest until his death Celestial Sphere Theory similar to the geocentric theory, it said that we see in the sky what is was actually numerous spheres. (These spheres are like clear globes around earth with planets, comets and stars inside of them) some of these were thought to be in our own atmosphere and others farther away. even Copernicus (heliocentric theory) still believed in these spheres. His model of the universe had the stars at equal distance from the earth in one of the most distant spheres tycho brahe disproved the celestial sphere theory that all celestial objects were unmoving object's in the earth's sky. He demonstrated it was untrue through observation of a supernova, which he proved beyond the solar system and not a phenomenon within the Earth's atmosphere Johannes Kepler a mathematician who proposed the 3 laws of planetary motion. stated that the planets move in an elliptical orbit around the sun and mathematically proved it. His laws provided the building blocks for many future theories first law of planetary motion LAW OF ELLIPSES- the planet's orbits are elliptical in nature and that the center of the sun is a focus for those ellipses