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384 BCE
Aristotle
Aristotle believed that the sun orbited the Earth. He also believed that the planets and stars were round including Earth. He further thought that the movements of the planets must be round because they were spheres, and if the movements were round they would go on forever. -
100
Ptolemy
Ptolemy believed that the Earth was the center of the universe. They called this The "geocentric" theory. He was able to combine the movement of the stars with mathematics to predict the movements of the planets. He thought that the planets moved in smaller circles and the Earth moved along an equant. -
1473
Copernicus
Copernicus believed that the sun was the center of the universe and the Earth revolves around it. He also introduced the idea to the public that the Earth spins on an Axis once daily. This was the Heliocentric system. -
1546
Tycho Brahe
Tycho believed in the heliocentric universe. He invented astronomical instruments and fixed the position of the stars. Brahe made some of the most accurate observations of the planets positions. One of Brahe's inventions was the Tyconian Quadrant which was widely copied and led to the invention of improved observational equipment. -
1564
Galileo
Galileo believed in the Heliocentric universe and his observations strengthened the belief of others. Galileo also discovered and studied many things. He discovered Jupiter's four moons, and he studied and observed Saturn and the phases of Venus. -
1570
Hans Lippershey
Hans Lippershey is commonly believed to be the inventor of the telescope. He was a Dutch eyeglass maker and he is also credited with the invention of the compound microscope. Many Historians believe that he invented the designs for the refracting telescope in 1608. -
1571
Johannes Kepler
Johannes was a German astronomer who discovered three major laws of planetary motion. 1) The planets move in elliptical orbits with the Sun at one focus. 2) The time necessary to traverse any arc of a planetary orbit is proportional to the area of the sector between the central body and that arc (the “area law”). 3) There is an exact relationship between the squares of the planets’ periodic times and the cubes of the radii of their orbits (the “harmonic law”). -
Giovanni Cassini
Giovanni discovered several things during his time. One of the things he discovered were the rings of Saturn in 1675. He also shares credit with Robert Hooke for the discovery of The Great Red Spot on Jupiter around 1665. Giovanni was also the first to observe many things such as, Saturn's moons and in 1690 the observation of differential rotation within Jupiter's atmosphere. He also used a method outlined by Galileo and made successful measurements of Longitude. -
Sir Isaac Newton
Newton discovered and invented many things that had a huge impact on life. He discovered Newtons Law of Universal Gravitation, and Newtons Three Laws of Motion. He also invented the reflecting telescope and Newtons Method, it is one example of a root-finding algorithm. -
The difference between refracting and reflecting telescopes
The refracting telescope has two lenses one that collects the light from objects, such as stars, and bends it into a single point of focus, and one that enlarges the image large enough for our retinas. The reflecting telescope uses mirrors instead of lenses. The light from an object enters the telescope and is reflected off of the first mirror and the second mirror reflects the image into the eyepiece. -
William Herschel
Herschel observed and discovered many things. In 1781 he observed the Orion Nebula. He also discovered, what he thought was a comet but was really Uranus, and it's two moons. He also formulated a theory of stellar evolution. -
Percival Lowell
Lowell was an astronomer who initiated the search that concluded in the discovery of Pluto. He also had speculation of life on Mars. He is remembered by him founding the Lowell Observatory in Flagstaff, Arizona. -
Ejnar Hertzsprung
Hertzsprung was a Danish astronomer who discovered two asteroids. The first one he discovered was the asteroid Kalahari in 1924 The second one he discovered was Ivar in 1929. It is a stony, armored asteroid near Earth. -
Albert Einstein
Albert Einstein was famous in many subjects such as Physics and Mathematics. He also worked in Astronomy. He was attempting to unify all the forces of the universe into one single theory, which he was still working on when he died. His work helps astronomers study and explain many things in space. -
Edwin Hubble
Edwin Hubble was a very important astronomer who discovered many things. Hubble saw red light from other galaxies and used the evidence to create his law that the universe is constantly expanding. He also created the classification system for the galaxies that is still used today. There is a telescope named after him called the Hubble Space Telescope. It is a telescope in space that orbits the Earth. -
Karl Jansky
Jansky was an American physicist and radio engineer. In August 1931 he discovered radio waves from The Milky Way. He was large influence on the study of radio astronomy. -
Sputnik
The Sputnik is a Soviet Union satellite that was set out into orbit on October 4, 1957. The Sputnik was the first man-made object to go into space and orbit the Earth. The U.S had planned to be the first to launch a satellite to orbit Earth and there was even one in the making. This was very large for the rest of the world because this was the marking of the beginning of the space race. -
Yuri Gagarin
Yuri Gagarin was the first man in space. The soviet union launched him off in the spacecraft Vostok on April 12, 1961. His flight lasted 108 minutes and he made one full orbit around the Earth. -
John Glen
John Glen was an American astronaut who was the first American to orbit the Earth. The U.S launched him and six others of on February 20, 1962. They orbited the Earth three times. -
The Apollo Program
The Apollo Program was a series of flights by NASA that went into space. There were 11 flights in total with one of the flights resulting in the first person on the moon. Four of the flights were to test the equipment, and six of the seven other flights landed on the moon. In this program a total of 12 astronauts walked on the moon, Neil Armstrong being the first. -
Neil Armstrong
Neil Armstrong was an American astronomer. He was the first person ever on the moon. He stepped foot on the moon on July 20, 1969. He flew in the Gemini 8, which launched off on July 16, 1969 with, Buzz Aldrin, Michael Collins, and a few others. -
The First Space Shuttle Flight
This was the first flight of NASA's space shuttle program. The flight was the Columbia. It launched on April 20, 1981. It returned 54.4 hours later on April 14. It orbited the Earth 4 times. It carried two people, John W. Young and Robert L. Crippen. -
Mars Pathfinder Expedition
The Mars Pathfinder was a rover that was sent o Mars to test technology. It launched December 4, 1996 and landed on Mars July 4, 1997. It was sent 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
The spacecraft was sent to Saturn to gather data and information. It reached Saturn in July, 2004, and plunged into Saturn atmosphere on September 15, 2017. It sent valuable information back to Earth. The spacecraft discovered many things such as water erupting from Enceladus, and tracking down a few new moons for Saturn. -
Last Breath of a Dying Star
EOS's very large telescope picked up a shell of glowing gas which turned out to be the "last breath of a dying star." The glow from the planetary nebula ESO 577-24 only lasts about 100,000 years,which is very short in astronomical terms.
