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322 BCE
Aristotle
322- Aristotle was an ancient Greek philosopher and scientist. He was considered the father of western philosophy. Aristotle created the idea that the earth was was the center of the universe. He also believed all the planets and the stars were all spheres. -
168
Ptolemy
168- Claudius Ptolemy was a Greco-Roman mathematician, astronomer, geographer and astrologer. He believed that the Earth was the center of the Universe. The word for earth in Greek is geo, so we call this idea a geocentric theory. -
1543
Copernicus
1543- Nicolaus Copernicus was a Renaissance-era mathematician and astronomer who formulated a model of the universe that placed the Sun rather than the Earth at the center of the universe. -
Tycho Brahe
1601- Made some of the most accurate observations of planetary positions which would eventually prove useful to his predecessors. He was a supporter of geocentric. -
Hans Lippershey
1619- He was a German-Dutch spectacle maker. He is known for making the telescope in the early 1600's. -
Johannes Kepler
1630- He is German astronomer who discovered three major laws of planetary motion. These works also provided one of the foundations for Isaac Newton's theory of universal gravitation. -
Galileo
1642- Galileo is known for all his space discoveries through his telescope. He is also known for his discovery of the four most massive moons of Jupiter. -
Giovanni Cassini
1712- Giovanni Cassini was an Italian mathematician, astronomer and engineer. Cassini is known for his work in the fields of astronomy and engineering. Cassini discovered four satellites of the planet Saturn and the division of the rings of Saturn. -
Sir Isacc Newton
1724- He contributed significantly to the field of science. He invented calculus and provided a clear understanding of optics. But his most significant work had to do with forces, and specifically with the development of a universal law of gravity. -
What is the difference between and refracting and reflecting telescope?
A refracting telescope is telescope which uses a converging lens to collect the light. A reflecting telescope is telescope in which a mirror is used to collect and focus light. One telescope uses a converging lens and the other uses a mirror lens. -
William Hershel
1822- He is founder of sidereal astronomy for observing the heavenly bodies. He found the planet Uranus and its two moons, and formulated a theory of stellar evolution. -
Percival Lowell
1916- He was an astronomer who fueled speculation that there were canals on Mars. He founded the Lowell Observatory in Flagstaff, Arizona and formed the beginning of the effort that led to the discovery of Pluto 14 years after his death. -
Karl Jansky
1950- Karl Jansky was an American physicist and radio engineer who in August 1931 first discovered radio waves emanating from the Milky Way. He is considered one of the founding figures of radio astronomy. -
Edwin Hubble
1953- He played a big role in establishing the fields of collection astronomy and observational cosmology and is regarded as one of the most important astronomers of all time. His meticulous studies of spiral nebula proved the existence of galaxies other than our own Milky Way. -
1955
1955- As a physicist, Einstein had many discoveries, but he is perhaps best known for his theory of relativity and the equation E=MC2, which foreshadowed the development of atomic power and the atomic bomb. -
Sputnik
1957- Sputnik 1 was the first artificial Earth satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957, orbiting for three weeks before its batteries died, then silently for two more months before falling back into the atmosphere -
Yuri Gagarin
1961- He became the first human to journey into outer space when his Vostok spacecraft completed one orbit of the Earth on 12 April 1961. It lasted 108 minutes as he circled the Earth for a little more than one orbit in the Soviet Union's Vostok spacecraft. -
John Glenn
1962- Colonel John Herschel Glenn Jr. was a United States Marine Corps aviator, astronaut, businessman. He was the first American to orbit the Earth, circling it three times in 1962. -
Ejnar Hertzsprung
1967- Keenly interested in the chemistry of photography, he turned to astronomy in 1902, working in small Danish observatories, where he applied photography to the measurement of starlight. He showed that a relationship exists between the colors of the stars and their true brightness . -
Neil Armstrong
1969- Neil Alden Armstrong was an American astronaut and aeronautical engineer who was the first person to walk on the Moon. He was also a naval aviator, test pilot, and university professor. -
The Apollo Program
1972- The Apollo program, also known as Project Apollo, was the third United States human spaceflight program carried out by the National Aeronautics and Space Administration, which succeeded in landing the first humans on the Moon from 1969 to 1972. -
First Space Shuttle Flight
1981- The Space Shuttle program was the fourth human spaceflight program carried out by the National Aeronautics and Space Administration, which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. -
Mars Partfinder Expedition
1996- It was a relatively inexpensive mission that tested out many of the technologies build into later missions, like the Mars Exploration rovers Spirit and Opportunity. The purpose of Pathfinder was to prove that the concept of faster, better and cheaper missions would work. -
Cassini Orbiter
1997- The Cassini orbiter mission, 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. -
Voyager 2 Spacecraft Reaches Interstellar
2018- The spacecraft, which launched in 1977, has spent more four decades exploring our solar system, most famously becoming the only probe ever to study Neptune and Uranus during planetary flybys. Now, it has joined its predecessor Voyager 1 beyond the bounds of our sun's influence, a milestone scientists weren't able to precisely predict when would occur.
