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322 BCE
Aristotle
(384-322 B.C.) Aristotle believed that the Earth was the center of the universe, and that the sun, moon, stars, and other planets were all connected to a clear "shell" that rotates around the Earth. -
120 BCE
HIpparchus
(190-120 B.C.) Hipparchus discovered precession of the equinoxes. He compiled the first known star catalog, calculated the distance between the Earth and moon, and he calculated the length of the year. -
168
Ptolemy
(100-168) Ptolemy believed that that the Earth that the Earth was the center of the universe. The word for Earth in Greek is geo so this is called the geocentric theory. -
1543
Copernicus
(1473-1543) Copernicus thought the Earth was placed near the center of the universe, but revolved around the sun on an axis. Helio in Greek means sun. -
Tycho Brahe
(1546-1601) Brahe was known for his most precise instruments and accurate measurements. He had enough data to show the movement of the sun and other planets. -
Hans Lippershey
(1570-1619) Hans Lippershey he was a lens maker and was considered the creator of the telescope because he was the first one to try to obtain a patent. His telescope was magnified by 3x. -
Johannes Kepler
(1571-1630) kepler worked with Tycho Brahe. He discovered the major laws of planetary motions. They move in ovals around the sun, this is called ellipticals. -
Galileo
(1564-1642) Galileo invented a new telescope that allowed him to discover four moons circling jupiter. IO, Callisto, Ganymede, and Europa. He discovered sunspots. And found that the stars were not fixed to the “clear shells” Aristotle thought they were connected to. -
Giovanni Cassini
(1625-1712) Cassini discovered differences in saturn's ring. He discovered, among others, the dark space between rings A and B. he also discovered four moons of saturn and was the first to record observations of the Zodiacal light. -
Sir Isaac Newton
(1642-1727) Newton formulated the law of graviton and discovered the laws of physics. He was the first to explain tides scientifically. -
William Herschel
(1738-1822) Herschel discovered the planet Uranus. He determined the temperature of the different colors of sunlight that passed through a prisim. -
Percival Lowell
(1855-1916) Lowell discovered the planet Pluto and studied the “canals” on mars. He built an observatory in flagstaff to study mars. -
Karl Jansky
(1905-1950) Jansky found radio waves are coming from space. -
Edwin Hubble
(1889-1953) Hubble used the color of stars and discovered the universe is expanding. -
Albert Einstein
(1879-1955) Einstein discovered the equation that helped explain special relativity. -
Sputnik
sputnik was the first ever satellite. It was a huge turning point in history and astronomy. It was sent out by Russia. -
Yuri Gagarin
In 1961 Gagarin was the first person to orbit the Earth and was from Russia. -
John Glenn
In 1962 Glenn was 1st U.S. citizen to orbit Earth 3 times. -
Period: to
Apollo missions
(1963-1972) The Apollo program was designed to land humans on the Moon and bring them safely back to Earth. -
Ejnar Hertzsprung
(1873-1967) Hertzsprung discovered the Hertzsprung diagram which is the absolute magnitude plotted against the surface temperature for a group of stars. -
Neil Armstrong
In 1969, Armstrong was the first man on the moon -
First space shuttle flight
In 1981 the Space Shuttle Columbia was launched. It was like an airplane attached to a rocket. It shot up like a rocket, then the “plane” part disconnected and would orbit then fall and land like a regular airplane. -
Mars pathfinder Expedition
It was designed as a technology demonstration of a new way to deliver an instrumented lander and the first-ever robotic rover to the surface of the red planet -
Cassini Orbiter
It was a collaboration between NASA, the European Space Agency, and the Italian Space Agency to send a probe to study the planet Saturn and its system, including its rings and natural satellites. The Saturn orbiter is named after Jean-Domenique Cassini, who discovered the Saturnian satellites Lapetus in 1671. -
SpaceX Falcon Heavy
reusable heavy-lift launch vehicle designed and manufactured by SpaceX. It is derived from the Falcon 9 vehicle and consists of a strengthened Falcon 9 first stage as a central core with two additional first stages as strap-on boosters.
