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322 BCE
Aristotle
384-322 BCE
Aristotle was an ancient Greek philosopher. He believed in a geocentric universe (The earth is in the center of everything) Aristotle also believed that all of the planets and stars were perfect spheres. -
168
Ptolemy
100-168
Ptolemy was an astronomer who contributed the work of the Almagest. Almagest showed the theory of the motion of the Sun, Moon and Planets. Ptolemy presented details of how how each planet moved. He used geometric models to predict the positions of the sun, moon and planets using combinations of circular motion. He was also able to find the lengths of seasons. -
1543
Copernicus
1473-1543
Copernicus was an astronomer in the Renaissance era. He made a model that placed the Sun in the center of the universe rather than Earth. This was called the Heliocentric system. Copernicus established that the planets orbited the sun rather than the Earth. He laid out his model of the solar system and the path of the planets. He also determined that the earth rotates daily on its axis and that earths motion affected what people say in the heavens. -
Tycho Brahe
1546-1601
Tycho Brahe was a Danish astronomer who was known for his precise and accurate astronomical and planetary observations. His work helped overturn the belief of the Heliocentric model of the universe. He believed instead of the sun as the center of the universe that the earth was which was an opposition to Copernicus's belief. Tycho Brahe made some of the most accurate observations of planetary positions. -
Hans Lippershey
1570-1619
Lippershey was a German-Dutch spectacle-maker. He is usually associated with the invention of the telescope, because he was the first one who tried to obtain a patent for it. He invented telescopes, a refracting telescope. A refracting telescope is one that uses converging lens to collect the light. Its original use was for spy glasses and astronomical telescopes. They present a brighter, clearer and more magnified view for astronomers. -
Johannes Kepler
1571-1630
Johannes was a German astronomer who was a key figure of the revolution. His most famous accomplishment are his three laws of planetary motion which laid the foundation of celestial mechanics. He made several other important contributions to science too. He discovered that the planets orbited elliptically(oval orbit) around the sun which is still proven today. -
Galileo
1564-1642
Galileo was an Italian astronomer who has always been called "father of observational astronomy". His investigation of the laws of motion and improvements of the telescope helped later people to understand the universe. Galileo contributed the telescope and the laws of dynamics. He was a important figure in modern astronomy because of his contributions and his work in physics and its relation to astronomy. -
reflecting vs refracting telescopes
1619 & 1668
A reflecting telescope uses two mirrors instead of two lenses (it was also created in 1668). The reflecting telescope don't cause chromatic aberration while the refracting telescope does. Reflecting telescopes are easier to mount. A refracting telescope bends light over lenses to make up the image while in a reflecting one the light is bouncing off the mirrors to make a clear image. -
Giovanni Cassini
1625-1712
Giovanni Cassini was a french astronomer. He was associated with a number of scientific discoveries such as the observations of Saturn's moons. Cassini discovered four satellites of the planet Saturn and discovered that Saturn did not just have one ring around it but it had multiple rings. The Cassini Division was named after him. -
Sir Isaac Newton
1643-1724
Sir Isaac Newton was most famous for his law of gravitation, it was crucial in the scientific revolution of the 17th century. His law states that every particle attracts every other particle in the universe with a force which is proportional to the product of their masses. Newton was a tinkerer as well, but more with ideas than physical inventions. He did invent reflecting lenses for telescopes, which produced clearer images in a smaller telescope. -
William Herschel
1738-1822 Sir William Herschel was a German&British astronomer who is credited as the founder of sidereal astronomy (a day that measures the rotation of Earth relative to the stars rather than the sun) it helps astronomers keep time and know where to point their telescopes. He also was known for observing the heavenly bodies which is just anything in the sky. He also found the planet Uranus and its two moons. -
Percival Lowell
1855-1916
He was a american astronomer who is best known for forming a theory that there was life on Mars, a vision that has had enormous impact on the development of Science Fiction. Lowell also discovered Pluto. He also founded the Lowell Observatory in Flagstaff Arizona. -
Karl Jansky
1905-1950
He first discovered radio waves emanating from the Milky Way. Jansky was assigned the job of investigating the sources of static that might interfere with radio voice transmissions. He eventually figured out that the radiation was coming from the Milky Way and was strongest in the direction of the center of our Milky Way galaxy. -
Edwin Hubble
1889-1953
Edwin Hubble was a astronomer who was often called "Pioneer of the distant stars" His studies of spiral nebulae(cloud of gas and dust in outer space) proved the existence of galaxies other than our own Milky Way. He revolutionized the field of astrophysics. His research helped prove that the universe is expanding, and he created a classification system for galaxies that has been used for several decades. -
Albert Enstein
1879-1955
Albert Enstein came up with the theory relativity which revolutionized modern astrophysics. His theory of relativity, determined that the laws of physics are the same for all non-accelerating observers, and he showed that the speed of light within a vacuum is the same no matter what speed any an observer travels. With this he determined that massive objects cause a deformation in space-time, which is felt like gravity. -
Sputnik
Sputnik was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit on 4 October. It was orbiting for three weeks before its batteries died, then for two more months before falling back into the atmosphere. Sputnik provided scientists with valuable information, the density of the upper atmosphere could be deduced from its drag on the orbit, and the propagation of its radio signals gave data about the ionosphere (layer that contains high concentration of ions) -
Yuri Gagarin
Yuri Gagarin was from Russia and was the first person to fly in space. His flight, on April 12, 1961, lasted 108 minutes as he circled the Earth for a little more than one orbit. -
Ejnar Hertzsprung
1873-1967
Ejnar was a danish astronomer who classified types of stars by relating their color to their absolute brightness. He came up with the HR diagram to do so. The HR diagram plots the temperature of stars against their luminosity or the color of stars against their absolute magnitude to classify them. -
The Apollo Program
1963-1972
The Apollo program was designed to land humans on the Moon and bring them safely back to Earth. Six of the missions managed to achieve this goal. The crew for the program was Neil A. Armstrong, commander Michael Collins, Command Module pilot and Edwin E. Aldrin Jr. , Lunar Module pilot. A lot of the missions were canceled for a variety of reasons, including changes in technical direction, the Apollo 1 fire, hardware delays, and budget limitations. -
The first space shuttle flight
1981
Columbia was the first shuttle to reach space, in 1981. However, the shuttle and a seven-member crew were lost over Texas when Columbia burned up during re-entry on Feb. 1, 2003. Columbia's loss encouraged NASA to do extra safety checks in orbit for all future missions. -
Mars Pathfinder Expedition
1996
Mars Pathfinder. Mars Pathfinder was launched December 4, 1996 and landed on Mars' on July 4, 1997. This mission was the first of a series of missions to Mars that included rovers, and was the first successful lander since 1976. The purpose of it to have a relatively inexpensive mission that tested out many of the technologies build into later missions -
Cassini orbiter
1997
Cassini orbiter was one of the most ambitious missions ever launched into space.It was for vibration and thermal testing Loaded with an array of powerful instruments and cameras, the spacecraft was capable of taking accurate measurements and detailed images. The orbiter reached Saturn and its moon in July 2004. It was equipped for 7 different science investigations. The spacecraft was launched with two elements: the Cassini orbiter and the Huygens probe. -
Neil Armstrong
1930- 2012
Apollo 11 was the spaceflight that landed the first two people on the Moon those two men included Neil Armstrong. He made history by becoming the first man to walk on the moon. He developed a fascination with flight at an early age and earned his student pilot's license when he was 16. His first words on the moon were, 'That's one small step for a man, one giant leap for mankind'. -
John Glenn
1921-2016
John Glenn was a United States astronaut. He was the first American to orbit the Earth. It took him 4 hours 56 minutes to do so. He circled it three times in 1962. He reached speeds of more than 17000 miles per hour. The successful mission ended with a splash down landing the the Atlantic ocean. -
New Galaxy discovered on accident!
2019
This Galaxy was recently discovered accidentally when astronomers used the Hubble Space Telescope to photograph the globular star cluster. The telescope's sharp vision uncovered a never before seen dwarf galaxy located far behind the cluster’s crowded stellar population. It measures only around 3,000 light-years at its greatest extent and it is roughly a thousand times dimmer than the Milky Way.
