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384 BCE
Aristotle
Aristotle thought the sun, moon, stars, and planets travel on separate spheres. He prove the Earth is spherical and that the Earth is the center of the universe. -
190 BCE
Hipparchus
Hipparchus discovered the precession of the equinoxes and solstices. He calculated the length of a year and the distance between the Earth and the Moon. He also made the first catalog of stars -
100
Ptolemy
Ptolemy believed the Earth is at the center of the universe and everything orbits around it, the geocentric theory. Geo meaning Earth and centric being the center. He also wrote a book called "Almagest". -
1473
Copernicus
Copernicus believed the sun is at the center of the Earth and everything orbits around it, heliocentric. Helio meaning sun in Greek and centric meaning the center. Copernicus also invented the scientific method. -
1546
Tycho Brahe
Brahe is known for his accurate and comprehensive astronomical instruments and planetary observations. He recorded enough motion of sun, planets, and moon relative to the fixed stars to within 1 arc minute -
1564
Galileo
Galileo was in Italian scientist who discovered four of the moons circling Jupiter (Io, Europa, Ganymede, Callisto). He made a telescope, discovered sunspots, and found out that stars aren’t attached to invisible spheres surrounding earth. -
1570
Hans Lippershey
Lippershey is a spectacle-maker who used lens to make the first telescope (magnification 3x), called the refracting telescope which bends light. -
1571
Johannes Kepler
Kepler was Brahe's assistant who discovered that the orbit of the planets are not circular but elliptical (oval), the unification of astronomy and physics. -
Refracting Telescope
A telescope that uses a converging lens to collect light. Different from reflecting because instead on bending, it collects light. -
Giovanni Cassini
Discovered the cassini division (the dark gap between the rings A and B of Saturn). -
Sir Isaac Newton
Newton developed further works of Copernicus and Kepler using math, he invented the reflecting telescope which shines the image back. He also made the 3 laws of motion. -
Reflecting Telescope
A telescope which causes an image to reflect at a focus point by using mirrors. -
William Herschel
Discovered the planet uranus and its two moons, and discovered 2 more of saturn's moons. He thought to have found polar ice on mars leading to the studies hoping to find water on mars. Theory of stellar evolution, meaning stars go through different phases. William Herschel also discovered rainbow spectrum infrared light exists which happens when white light goes through a prism you see the real color (determined on the temperature). -
Percival Lowell
Lowell predicted the existence of a planet beyond the orbit of Neptune (Pluto) and discovered Mars. -
Ejnar Hertzsprung
Classified stars by relating their color to their brightness categorized into the HR Diagram. -
Edwin Hubble
Discovered galaxies are moving away from each other and that the universe is continuously expanding and that a galaxy's velocity is proportional to its distance. this is called the Big Bang Theory, meaning how the universe formed. -
Albert Einstein
Made the theory of relativity and gravitation - proved 2 years ago -
Karl Jansky
He was first to discover radio waves come from the Milky Way/space (founding figure of radio astronomy). Radio waves are the longest type of energy -
Yuri Gagarin
First man in space. 108 minute orbital flight in his Vostok 1 spacecraft. -
Apollo Missions
This were a series of missions to the moon, they had 6 successful attempts. We wanted to send them to the moon and bring them back. -
John Glenn
First American to orbit space, also second man to go on the moon. -
Sputnik
Russia was successful in launching their first satellite into space to orbit Earth. Russia was starting to get ahead of us so it became a race to see who the first person to go to space is, starting NASA. -
Neil Armstrong
First man from the US to walk on the moon. -
First Space Shuttle Flight
This was the first space shuttle, it launched like a rocket, but landed like an airplane -
Mars Pathfinder Expedition
A rover was launched to probe Mars, and landed in 1997. -
Cassini Orbiter
Cassini orbiter is a probe launched to saturn to get accurate and detailed pictures. -
Space X Heavy Falcon
Heavy reusable launch vehicle that lifts up to 64 metric tons.
