* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download 16.6 NOTES How do astronomers measure distance? Objective
History of Solar System formation and evolution hypotheses wikipedia , lookup
Formation and evolution of the Solar System wikipedia , lookup
Astrophotography wikipedia , lookup
Astrobiology wikipedia , lookup
Aquarius (constellation) wikipedia , lookup
Tropical year wikipedia , lookup
Corvus (constellation) wikipedia , lookup
Theoretical astronomy wikipedia , lookup
Outer space wikipedia , lookup
Rare Earth hypothesis wikipedia , lookup
Astronomy in the medieval Islamic world wikipedia , lookup
Planetary habitability wikipedia , lookup
Spitzer Space Telescope wikipedia , lookup
Copernican heliocentrism wikipedia , lookup
Comparative planetary science wikipedia , lookup
Chinese astronomy wikipedia , lookup
Astronomical spectroscopy wikipedia , lookup
History of astronomy wikipedia , lookup
Extraterrestrial life wikipedia , lookup
Geocentric model wikipedia , lookup
International Ultraviolet Explorer wikipedia , lookup
Dialogue Concerning the Two Chief World Systems wikipedia , lookup
Observational astronomy wikipedia , lookup
Ancient Greek astronomy wikipedia , lookup
Hebrew astronomy wikipedia , lookup
Cosmic distance ladder wikipedia , lookup
16.6 NOTES How do astronomers measure distance? Objective: Identify two methods astronomers use to measure distances in space Most astronomers have found that distances to stars are so great that the numbers are too large to work with easily. For example, Proxima Centauri is the closest star to earth other than the Sun, and is 40,000,000,000,000 km from Earth. Special units are used to measure distances in space. A light year is equal to the distance light travels in one year (about 10 trillion km). Light from the Sun reaches Earth in a little more than 8 minutes. Light from the North Star (Polaris), reaches earth in about 700 years. Astronomers can use parallax to find out distances to the closer stars. Parallax is the apparent change in the position of a distant object when seen from two different places. An astronomical unit is the average distance from Earth to the Sun. It is equal to about 150 million km. An astronomical unit, or AU, can also be used to measure distances in space, especially distances between the planets in the solar system. http://www.youtube.com/watch?v=-6szEDHMxP4&feature=related