-
322 BCE
Aristotle
Aristotle believed in a geocentric Universe and that the planets and stars were perfect spheres though Earth itself was not. He suggested that the movements of the planets and stars must be circular since the motions were circular, and they could travel forever. -
168 BCE
Ptolemy
He believed that the Earth was the center of the Universe. -
1543
Copernicus
He suggested the theory that the Sun is at rest near the center of the Universe, and that the Earth, spinning on its axis once daily, revolves annually around the Sun. -
Tycho Brahe
Tycho made astronomical instruments in measuring and fixing the positions of stars paved the way for future discoveries.
He made some of the most accurate observations of planet positions which would eventually prove useful. Brahe invented many instruments such as the Tyconian Quadrant which were widely copied and led to the invention of improved observational equipment -
Hans Lippershey
Hans was the inventor of the first telescope and is credited with the invention of the compound microscope. The earliest workings towards the design of the telescope. He came up with the telescope as he made eyeglasses and he used a lens with powerful zooming abilities to see very distant objects. -
Johannes Kepler
Dicovered the three major laws of planetary motion. The three are that the planets orbit the sun, The time necessary to traverse any arc of a planetary orbit is proportional to the area of the central body and the "area law", and that there is an exact relationship between planets periodic times and the radii of orbits. -
Galileo
Galileo's observations strengthened his belief in Copernicus' theory that Earth and all other planets revolve around the Sun.
He discovered four of the moons circling Jupiter, how to study Saturn, how to observe the phases of Venus, and to study sunspots on the Sun. -
Difference between refracting and reflecting telescopes
A reflector telescope uses two mirrors instead of two lenses. The reflector is used to combat chromatic aberration. A mirror used to gather light doesn't suffer from this. Refractor telescopes is made with to lenses to help focus light to a single point. -
Giovanni Cassini
Cassini was the first to spot Saturn's moons. He was the first to measure the lines of longitude. He discovered the rings of Saturn and the great red spot on Jupiter. He also was the first to observe different rotation within Jupiter's atmosphere. -
Sir Isaac Newton
Newton developed three laws of motion which today are basic physics. He developed the theory of gravity, physics, and calculus. He also helped make the reflecting telescope. -
William Herschel
William Herschel discovered a what he thought was a comet was actually Uranus and its two moons. He discovered the planet with a home-made telescope. He also discovered infrared light and radiation by passing this light through a glass prism seeing the color spectrum. -
Percival Lowell
Lowell fueled speculation that their was life on Mars. He was an American astronomer who predicted a planet beyond Neptune and an initiated search led to the discovery of Pluto. Founded the Lowell Observatory in Flagstaff. -
Karl Jansky
Jansky discovered radio waves emanating from the Milky Way. He called this radio astronomy. Jansky also invented the Radio Telescope. -
Edwin Hubble
Hubble proved that the Universe is expanding and their are more galaxies than the milky way. He also proposed the Big Bang Theory. He also identified the relationship between a galaxies distance and the speed it is moving and how to compare two galaxies. -
Albert Einstein
Einstein is responsible for theory of relativity, time and gravity, basic physics, and orbital motions. -
Sputnik
Sputnik is a Soviet satellite and was sent into space to give scientist information on what space was like. The satellite was made to collect space atmosphere, temperature, gravity levels, and more. It also measured latitude and longitude lines. -
Yuri Gagarin
First man to enter space and lasted 108 minutes and circled tthe earth a little over 1 time. Soviet Union. -
John Glenn
First American to orbit the earth and he circled it 3 times. He spent around 5 hours in space. -
Ejnar Hertzsprung
Hertzsprung classified stars by their relating color and absolute brightness. He also discovered Asteroids Ivar and Kalahari. -
Neil Armstrong
First man to walk on the moon. NASA astronaut. Flew in space earlier on the Gemini 8 mission in 1966. -
The Apollo Program
Apollo was a NASA program that made a total of 11 flights in space. Scientists collected data and conducted research. They studied the lunar surface and took moon rocks back to Earth. -
First Space Shuttle flight
The shuttle orbited Earth a whopping 36. It was the first American flight of a space since the last Apollo mission. Did atmospheric testing. -
Mars Pathfinder Expedition
Spacecraft that landed a base station with a roving probe on Mars. The mission was the first of a series of missions to mars. Tested new technology. -
Cassini orbiter
Cassini reached Saturn and its moons bringing home valuable data that transformed understanding of the Saturnian system. Orbited Saturn and found that water erupted from Enceladus. -
Hubble discovers a new galaxy
The Hubble discovered a dwarf galaxy 30 million light years away. Using Hubble's advanced cameras astronomers were able to see compact collection of of stars. It is 3000 light years old and is a fraction of the milky way.
