2. Extremely large: "The cost of this house was astronomical!"
Astronomers use the information to locate stars, planets, and asteroids; and to forecast eclipses and lunar phases.
It was originally used by astronomers to calculate astronomical time.
2. A clock indicating the movement of the sun, planets, and other astronomical data.An organization that conducts astronomical research through the use of such a structure.
A spectroscope is an instrument for dispersing light; usually, light in the visible range, into a spectrum in order to measure it; such as, a continuous distribution of colored light produced when a beam of white light is dispersed into its components; for example, by a prism.
2. A telescope that collects, detects, or records electromagnetic radiation emitted from extraterrestrial sources.
2. Any standard of time based on astronomical observations.
3. A system of time measurement formerly used by astronomers, based on solar time in a mean solar day beginning at noon, and superseded by civil time.
2. A unit of length used by astronomers to measure distances in space.
One astronomical unit, or AU, is equal to the average distance between the earth and the sun, which is 92,955,806 miles or 149,597,870 kilometers.
Astronomy is considered by some to be the oldest recorded science. This concept is based on records from ancient Babylonia, China, Egypt, and Mexico.
The first true astronomers are said to be the Greeks, who deduced the earth to be a sphere and attempted to measure its size. A summary of Greek astronomy came to us from Ptolemy of Alexandria's Almagest.
The Arabs developed the astrolabe and produced good star catalogs while in 1543, the Polish astronomer Copernicus demonstrated that the sun, not the earth, is the center of our planetary system
The Italian scientist Galileo was the first to use a telescope for astronomical study, 1609-1610.
The British astronomer William Herschel's suggestions on the shape of our galaxy were verified in 1923 by the U.S. astronomer Edwin Hubble's telescope at the Mount Wilson Observatory in California.
Recent extension of the powers of astronomy to explore the universe has been made possible in the use of rockets, satellites, space stations, and space probes, while the launching of the Hubble Space Telescope into permanent orbit in 1990 has made it possible for the detection of celestial phenomena seven times more distant than by any earth-based telescope.
For simplicity, an AU is usually rounded off to 93,000,000 miles or 149,637,000 kilometers.
2. An astronomical unit is used to describe planetary distances.Light travels this distance in approximately 8.3 minutes.