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Period: 1 CE to
Astronomy: Historical Events!
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140
Ptolemy perfects his geocentric model of solar system.
Ptolemy perfects his geocentric model of solar system. In his model the planets moved on circles that moved on other circles . The model could accurately predict the positions of the planets. Ptolemy also compiled a catalog of stellar brightnesses. -
1054
First record of the crab nebula
In 1054 AD the Chinese recorded a "bright star" that you could see even during daylight. The explosion of the star became known as the "Crab Nebula" and you can find pictures of it today! -
1330
Jean Buridan develops impetus theory of motion.
Jean Buridan develops impetus theory of motion. Buridan's theory of motion was remarkable in that it contradicted the established ideas of Aristotle. -
1465
Printing press used to produce astronomy books.
Regiomontanus uses printing to produce astronomy books and tables. Regimontanus used the recently invented art of printing to produce books, almanacs, and tables of predictions of the positions of the Sun, Moon, and planets. -
1504
Columbus uses lunar eclipse prediction to influence Arawaks.
From his almanac, Columbus knew that a lunar eclipse would occur on February 29. He impressed the Arawak's with his accurate prediction that the Moon would rise "inflamed with wrath". -
1543
The Renaissance and the modern astronomy.
During the Renaissance period modern astronomy began to take shape when Copernicus published his “De Revolutionibus Orbium Coelestium” which used empirical evidence to revive Aristrachus’ heliocentric view of the Universe -
William Gilbert proposes Earth has dipole magnetic field.
William Gilbert proposes Earth has dipole magnetic field. Gilbert proposed that the Earth acts like a big magnet whose field aligns the small magnet used as a compass needle. -
Galileo begins experiments with falling and rolling bodies.
Galileo begins experiments with falling and rolling bodies. Galileo's experiments led him to conclude that once something is set in motion it will remain in motion unless something stops it. This contradicted earlier ideas that said only rest was a natural state. -
Galileo observes Moon.
Galileo observes Moon. Galileo found that the Moon had mountains, valleys, and plains like the Earth. He called the dark regions of the Moon maria, the Latin word for seas. -
Galileo observes the phases of Venus
Galileo observes the phases of Venus. He found that Venus shows all the phases from new to full. The observation he made was incompatible with the Ptolemaic model of the solar system. -
Galileo discovers four largest satellites of Jupiter.
Galileo discovers four largest satellites of Jupiter. Galileo discovered that Jupiter is orbited by four large satellites/moons, now called, collectively, the Galilean satellites. This showed that at least some celestial bodies didn't orbit the earth -
Kepler discovers laws of planetary motion.
Kepler discovers laws of planetary motion. Working with Tycho's observations, Kepler discovers the shapes of planetary orbits, how the speed of a planet varies as it orbits the Sun, and the relationship between orbital distance and orbital period. -
Francis Bacon suggests that Earth's continents move about.
Francis Bacon suggests that Earth's continents move about. Bacon noticed that the eastern and western shores of the Atlantic were parallel and could be fitted together. -
Galileo publishes "The Dialogue".
Galileo publishes "The Dialogue". The Dialogue, although superficially a balanced debate about the merits of the geocentric and heliocentric models of the solar system, was in fact a powerful argument for the ideas of Copernicus. -
Bishop Ussher uses Bible to calculate age of Earth.
Bishop Ussher uses Bible to calculate age of Earth. From the chronology of Biblical events, Ussher concluded that the Earth was created in 4004 BC. -
Giovanni Cassini discovers Great Red Spot of Jupiter.
Giovanni Cassini discovers Great Red Spot of Jupiter. Its size and darkness have changed with time, however the Great Red Spot is still present and can be seen today. -
Sir Isaac Newton invented the first reflecting telescope.
Isaac Newton invented the first reflecting telescope which used a curved mirror instead of a lens to look further into space. Newton later publishes his hugely influential book called ‘Philosophiae Naturalis Principia Mathematica’ in which he agrees that the Earth rotates around the Sun and explains the reasons behind Kepler’s three laws. -
James Gregory makes the first realistic estimate of the distances of the stars.
James Gregory makes the first realistic estimate of the distances of the stars. Gregory assumed that the other stars were just as bright as the Sun and then calculated how distant they had to be to match their apparent brightnesses. -
Christian Huygens proposes that light consists of waves.
Christian Huygens proposes that light consists of waves. Huygens's ideas were disputed by Newton, who proposed that light was made up of a stream of particles. -
Christian Huygens proposes that light consists of waves.
Christian Huygens proposes that light consists of waves. Huygens's ideas were disputed by Newton, who proposed that light was mae up of a stream of particles. -
Edmund Halley correctly predicts the return of Comet Halley.
Edmund Halley predicts return of Comet Halley. Halley noted that comets with similar orbits had appeared in 1456, 1531, 1607, and 1682. He proposed that these were all the same comet and that it would return in 1758 or 1759 -
Edmund Halley discovers stars move through space.
Edmund Halley discovers stars move through space. Halley found that the positions of stars change with time. He explained the changes in position as due to the individual motions of stars through space. -
The First list of Nebulae.
Charles Messier makes list of nebulae. messier often mistook nebulae for comets Like other comet hunters, . He compiled a list of 103 nebulae to help other comet hunters. This was the first list of nebulae. -
William Herschel discovers speed and direction of Sun's motion.
William Herschel discovers speed and direction of Sun's motion. Herschel analyzed the motions of seven bright stars and showed that part of their motions was due to the motion of the Sun through space. -
Meteorite shower at l'Aigle convinces scientists that meteorites have an extraterrestrial origin.
Meteorite shower at l'Aigle convinces scientists that meteorites have an extraterrestrial origin. A careful investigation of the shower by Edouard Biot convinced most skeptics that meteorites really do fall from the sky. -
Gaspar de Coriolis discovers Coriolis effect.
Gaspar de Coriolis discovers Coriolis effect. The Coriolis effect, the apparent deflection of moving bodies due to Earth's rotation, explained many atmospheric circulation patterns. -
h Carinae brightens to become second brightest star.
h Carinae brightens to become second brightest star. h Carinae is normally too faint to be seen, but between 1837 and 1860 it was the brightest star in the sky. -
Christian Johann Doppler describes the Doppler effect.
Christian Johann Doppler describes the Doppler effect. Doppler discovered that the wavelength and frequency of a wave change if the source of the wave moves toward or away from the observer. -
Calculations of Adams and Leverrier lead to discovery of Neptune.
Calculations of Adams and Leverrier lead to discovery of Neptune. Adams and Leverrier independently calculated the location of the unknown planet, Neptune, that was required to explain discrepancies in the orbit of Uranus -
Giovanni Schiaparelli discovers "canals" of Mars.
Giovanni Schiaparelli discovers "canals" of Mars. Schiaparelli reported thin, dark lines crisscrossing the surface of Mars. The discovery raised the possibility of intelligent life on Mars. -
Joseph Stefan finds the rate at which a blackbody emits energy.
Joseph Stefan finds the rate at which a blackbody emits energy. Stefan found that the energy emitted by a blackbody increases as the fourth power of temperature. -
100" Mt. Wilson telescope completed.
100" Mt. Wilson telescope completed. The Mt. Wilson telescope was the largest optical telescope in the world for 31 years until the Palomar reflector was completed. -
Harlow Shapley find the size and shape of the Milky Way.
Harlow Shapley find the size and shape of the Milky Way. Shapley assumed that globular clusters are distributed uniformly about the center of the Milky Way. -
Harlow Shapley find the size and shape of the Milky Way.
Harlow Shapley find the size and shape of the Milky Way. Shapley assumed that globular clusters are distributed uniformly about the center of the Milky Way. From this, he found that the Earth is located 15,000 pc from the center of the Milky Way. -
Edwin Hubble working at Mount Wilson.
Edwin Hubble working at Mount Wilson Observatory and using a 60 inch reflector telescope proves that galaxies are separate systems outside of our own Milky Way and that the Universe is expanding. -
Edwin Hubble shows spiral nebulae are galaxies.
Edwin Hubble shows spiral nebulae are galaxies. Hubble identified individual Cepheid variable stars in spiral nebulae and used them to show that the spiral nebulae are huge collections of stars far from the Milky Way. -
Cecilia Payne shows stars of different classes have essentially the same chemical composition.
Cecilia Payne shows stars of different classes have essentially the same chemical composition. Payne determined the chemical composition of a number of stars of different spectral classes and found that they were nearly the same. -
Edwin Hubble Discovers Universe is Expanding.
Edwin Hubble discovers universe is expanding. Hubble found that the speed of recession of galaxies increases with distance. He explained that this is due to the expansion of the universe. -
S. Chandrasekhar shows white dwarf stars are made of degenerate electrons.
S. Chandrasekhar shows white dwarf stars are made of degenerate electrons. Chandrasekhar also showed that the more massive a white dwarf, the smaller it is and that there is a maximum mass. -
Karl Jansky makes first radio astronomy observations.
Karl Jansky makes first radio astronomy observations. Jansky found that the Milky Way galaxy is a source of radio emission. -
Grote Reber builds first radio telescope.
Grote Reber builds first radio telescope. Reber built the first antenna specifically designed for radio astronomy. Using the radio telescope, Reber made the first map of cosmic radio emission. -
Gerard Kuiper Proposes Existence of Kuiper Belt of Comets.
Gerard Kuiper proposes existence of Kuiper Belt of comets. Kuiper proposed that the comets with periods of less than 200 years originate in a flatted belt of comets whose inner edge lies just beyond the orbit of Neptune. -
Harold Ewen and Edward Purcell detect 21 cm line.
Harold Ewen and Edward Purcell detect 21 cm line. Ewen and Purcell used a radio telescope to detect emission from interstellar hydrogen atoms. -
The Beginning of the Space Age.
Russian Sputnik 1 satellite becomes the first man-made object to orbit the Earth marking the beginning of the space age. -
James Van Allen Discovers Van Allen Radiation Belts.
James Van Allen discovers Van Allen radiation belts. Explorer 1, the first satellite launched by the United States, carried a Geiger counter built by Van Allen. The Geiger counter showed that there are zones of trapped energetic ions and electrons beyond Earth's atmosphere. -
Horace Ballcock proposes model for sunspot cycle.
Horace Ballcock proposes model for sunspot cycle. Ballcock's model involved the twisting of solar magnetic fields lines because the rate of solar rotation varies with solar latitude. -
Marten Schmidt shows quasars have large red shifts.
Marten Schmidt shows quasars have large red shifts. Schmidt found that previously unidentified lines in the the spectrum of the quasar 3C 273 were actually red shifted lines of hydrogen. -
The First Moon Landing
Astronauts Edwin Aldrin and Neil Armstrong land on Moon. On July 20, 1969 Aldrin and Armstrong became the first people to land on the Moon. -
Last Mission to the Moon
Last Apollo mission to Moon. Apollo 17 concluded the series of lunar landings in which a dozen astronauts explored the Moon. -
The Voyagers reach Jupiter. (1 and 2)
Voyagers 1 and 2 reach Jupiter. The Voyagers used gravitational boosts from their encounters with Jupiter to speed outward to encounters with other planets in the outer solar system. -
The first and only spacecraft to go past mercury.
Mariner 10 encounters Mercury. After passing Venus, Mariner 10 encountered Mercury four times, sending back pictures of Mercury's surface. -
The Hubble Space Telescope.
The Hubble Space Telescope is put into orbit from space shuttle Discovery. The 2.4m aperture reflecting telescope continues to circle the Earth taking extremely sharp images of outer space. -
Planets Found Orbiting Stars Like the Sun.
Planets found orbiting stars like the Sun. Astronomers in the United States and Switzerland reported the first detections of Jupiter-like planets orbiting nearby Sun-like stars. -
Pathfinder lands on Mars.
Pathfinder lands on Mars, Mars Global Surveyor begins mapping of Mars. The Pathfinder lander and the Sojourner rover it carried landed in an ancient Martian riverbed -
Intentionally crashed?
Lunar Prospector intentionally crashed into Moon in attempt to identify water. None is found.
