# Astronomy test 2 nagmita

 Dr. Crazy likes to study.. Planetry nebulie Historical order of 5 dead white dudes 1. Copernicus 2. Brahe3. Kepler4. Galileo5. Newton First sun centered model of the solar system or universe was by Copernicus Best naked-eye astronomer was Brahe What is parallax? view an object from 2 different locations and measure it's distance, used by brahe Discusses planetary motions, 3 laws of ellipses of planets was by Kepler What are the 3 laws of ellipses? 1. Sun is the focus of a planet's ellipse2. Closer to sun, faster; farther from sun, slower3. Smaller ellipses have shorter periods, bigger ellipses have longer orbital periods. First observation of the sun Galileo 2 laws we need to know of Gravity? 1. object will stay in motion and a straight line unless acted upon by an outside force.2. F= ma What would happen to a planet's orbital speed if its mass were to be doubled but the distance stayed the same? It would orbit at the same speed When a planet is twice as far away from its star, how does the gravitational force change between them? The force will be 1/4 as strong When a planet becomes 3 times as massive, but the orbit is the same, How does the gravitational force change between the planet and the star? The force will be 3x as strong What are Epicycles? When Greeks added a second circle to the geocentric model. Keplers 3 laws 1. orbit of a planet around the sun is an ellipse2. There are equal areas and times of interval when a planet goes around the sun3. size of orbit determines orbital period. What can be learn by analyzing starlight? 1. A star's temp from its blackbody curve2. What atoms are present, from absorption lines in the spectrum.3. A star's motion AuthorNshrestha01 ID316783 Card SetAstronomy test 2 nagmita Descriptionsecond test of Dr. Crazy Updated2016-03-04T02:10:42Z Show Answers