The development of astronomy can be divided into four primary periods
- Ancient astronomy, dating from the first significant contributions of the earliest civilizations to the Almagest of Ptolemy.
- Medieval astronomy, from the decline of Alexandrian culture to the Renaissance.
- Modern astronomy, from the Copernican revolution to the present time.
- The new astronomy of astrophysics, primarily a product of the 20th century.
Astronomy is the science of the celestial bodies; such as, the sun, the moon, and the planets; the stars and galaxies; and all of the other objects in the universe.
Astronomy is concerned with their positions, motions, distances, and physical conditions; as well as, with their origins and evolutions.
Astronomy deals with the origin, evolution, composition, distance, and motion of all bodies and scattered matter in the universe.
Astronomy is considered to be the oldest recorded science because there are records which can be examined from ancient Babylonia, China, Egypt, and Mexico.
As far as we can determine, the Greeks were the first "true astronomers" because they deduced that the earth was a sphere and they attempted to measure its size. A summary of Greek astronomy can be found in Ptolemy of Alexandria's Almagest which contains nearly all that is known of the astronomical observations and theories of the ancients.
The Almagest is also described as being a text on astronomy written by Ptolemy in the second century A.D. setting out his view of the universe with the earth at its center surrounded by spheres.
Ptolemy’s model of an earth-centered universe influenced astronomical thought for over 1,300 years.
In 1543, the Polish astronomer Copernicus demonstrated that the sun, not the earth is the center of our planetary system; and the Italian scientist, Galileo, was the first to use a telescope for astronomical study, in 1609-1610.
The 17th century saw several momentous developments; such as, Johannes Kepler's discovery of the principles of planetary motion, Galileo's application of the telescope to astronomical observation, and Isaac Newton's formulation of the laws of motion and gravitation.
The most remarkable recent extension of the powers of astronomy to explore the universe is 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 enabled the detection of celestial phenomena seven times farther than by any earth-based telescope.
Summary of how history has resulted in the development of English continued from the main page of Get Words.