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388 BCE
Aristotle
(384-322 B.C., Greek), the great philosopher, proved that the Earth is spherical, and believed that it was at the center of the universe. His reason for believing this was actually quite scientific: he knew that if the Earth revolved around the Sun, then we should see the stars shift position throughout the year. -
190 BCE
Hipparchus
(190-120 B.C., Greek) is widely considered to be the greatest astronomer of ancient times. He compiled the first known star catalog to organize astronomical objects, and also came up with a scale to define the brightnesses of stars. A version of this magnitude system is still used today. He measured the distance from the Earth to the Moon to be 29.5 Earth diameters (we know today that the real value is 30 Earth diameters). -
85
Claudius Ptolemy
(85-165 A.D., Greek) was an astronomer who used Hipparchus' extensive observations to develop a model that predicted the movements of the Sun, Moon, planets, and stars. His model, called the Ptolemaic system, visualized an Earth-centered universe and assumed that all astronomical objects move at constant speeds in circular orbits. -
1473
Astronomer Nicolaus Copernicus
Astronomer Nicolaus Copernicus was instrumental in establishing the concept of a heliocentric solar system, in which the sun, rather than the earth, is the center of the solar system.Nicolaus Copernicus was born on February 19, 1473 in Torun, Poland. Circa 1508. He was also Heliolithic. -
Tycho Brahe
Tycho Brahe was a Danish nobleman, astronomer, and writer known for his accurate and comprehensive astronomical and planetary observations. He was born in the then Danish peninsula of Scania. (1546-1601) -
Hans Lippershey
Hans Lippershey, also known as Johann Lippershey or Lipperhey, was a German-Dutch spectacle-maker. He is commonly associated with the invention of the telescope, because he was the first one who tried to obtain a patent for it.(1570-1619) -
Johannes Kepler
Johannes Kepler was a German mathematician, astronomer, and astrologer. Kepler is a key figure in the 17th-century scientific revolution.(1571-1630) -
Galileo Galilei
Galileo Galilei was an Italian polymath. Galileo is a central figure in the transition from natural philosophy to modern science and in the transformation of the scientific Renaissance into a scientific revolution. He is from Italy. He discovered the sunspots.(1564-1642 AD) -
Giovanni Domenico Cassini
Giovanni Domenico Cassini was an Italian mathematician, astronomer and engineer. Cassini was born in Perinaldo, near Imperia, at that time in the County of Nice, part of the Savoyard state.(1625-1712) -
Sir Isaac Newton
Sir Isaac Newton PRS was an English mathematician, astronomer, theologian, author and physicist who is widely recognised as one of the most influential scientists of all time and a key figure in the scientific revolution.(1643-1727) -
Frederick William Herschel
Frederick William Herschel, KH, FRS was a British astronomer and composer of German and Czech-Jewish origin, and brother of fellow astronomer Caroline Herschel, with whom he worked.(1738-1822) -
The Mariner's Astrolabe
The Mariner's Astrolabe was used to determine the latitude of a ship at sea by measuring the noon altitude of the Sun or the meridian altitude of a star of known declination (photo courtesy Adler Planetarium and Astronomy Museum). ... A number of devices were used to measure the Sun's noon altitude. -
Percival Lawrence Lowell
Percival Lawrence Lowell was an American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars.(1855-1916) -
Karl Guthe Jansky
Karl Guthe 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.(1905-1950) -
Edwin Powell
Edwin Powell Hubble was an American astronomer. He played a crucial role in establishing the fields of extragalactic astronomy and observational cosmology and is regarded as one of the most important astronomers of all time.(1889-1953) -
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of relativity, one of the two pillars of modern physics. His work is also known for its influence on the philosophy of science.(1879-1955) -
Sputnik
Sputnik 1 was the first artificial Earth satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957. It was a 58 cm diameter polished metal sphere, with four external radio antennas to broadcast radio pulses -
Yuri gagarin
In 1961, Russian cosmonaut Yuri Gagarin (left, on the way to the launch pad) became the first human in space, making a 108-minute orbital flight in his Vostok 1 spacecraft. Newspapers like The Huntsville Times (right) trumpeted Gagarin's accomplishment. -
John Glenn
was a NASA astronaut. He was part of the first group of astronauts NASA picked. He was the first American to orbit Earth. He also became a U.S. senator. Later, he became the oldest person to fly in space. -
Neil Armstrong
was born in Wapakoneta, Ohio, on August 5, 1930. After serving in the Korean War and then finishing college, he joined the organization that would become NASA. He joined the astronaut program in 1962 and was command pilot for his first mission, Gemini VIII, in 1966. He was spacecraft commander for Apollo 11 -
Ejnar Hertzsprung
Ejnar Hertzsprung was a Danish chemist and astronomer, born in Copenhagen, Denmark. In the period 1911–1913, together with Henry Norris Russell, he developed the Hertzsprung–Russell diagram.(1873-1967) -
The Space Shuttle program
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 Pathfinder
Mars Pathfinder was launched December 4, 1996 and landed on Mars' Ares Vallis on July 4, 1997. It was designed 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. -
The Cassini–Huygens
The Cassini–Huygens mission, commonly called Cassini, 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.(1997 – 2017) -
The Apollo Program
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 (Apollos 11, 12, 14, 15, 16, and 17) achieved this goal. Apollos 7 and 9 were Earth orbiting missions to test the Command and Lunar Modules, and did not return lunar data.1999 -
Falcon Heavy
Falcon Heavy is the most powerful operational rocket in the world by a factor of two. With the ability to lift into orbit nearly 64 metric tons (141,000 lb)---a mass greater than a 737 jetliner loaded with passengers, crew, luggage and fuel--Falcon Heavy can lift more than twice the payload of the next closest operational vehicle. -
refracting telescope
A refracting telescope is a type of optical telescope that uses a lens as its objective to form an image. The refracting telescope design was originally used in spy glasses and astronomical telescopes but is also used for long focus camera lenses. -
The reflector telescope
It uses a mirror to gather and focus light. All celestial objects are so far away that all of the light rays coming from them reach the Earth as parallel rays. Because the light rays are parallel to each other, the reflector telescope mirror has a parabolic shape. The parabolic-shaped mirror focusses the parallel lights rays to a single point. All modern research telescopes and large amateur ones are of the reflector type because of its advantages over the refractor telescope.