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322 BCE
Aristotle
To this day one of the most famous ancient Greek astronomers is Aristotle;he believed that the Earth was geocentric, or the center of the solar system. He discovered that the Earth is a sphere, meaning that it’s shaped like a round ball rather than just a flat surface. -
168
Ptolemy
Claudius Ptolemaeus, also known as Ptolemy, was a Greek astronomer and mathematician who lived long ago- from about 100 to 170 AD. Just like we do today, Ptolemy, often stared up at the sky and wondered about the planets, stars and Sun. Based on his observations, mathematic calculations, and studies of other astronomers, he came up with the idea or theory, about how the universe works and how the planets and stars move known as the Ptolemaic System. -
1543
Copernicus
The first astronomer to popularize the idea that the Earth revolves around the Sun was, Nicolaus Copernicus, one of the most famous and important astronomers in history. He put forward that the Earth revolves around the Sun not the other way around. -
Tycho Brahe
Tycho Brahe a Danish astronomer whose work in developing astronomical instruments and in measuring and fixing the position of the stars paved the way for future discoveries. He believed that the Sun and the Moon revolved around the Earth and five other known planets revolved around the Sun. -
Hans Lippershey
Hans Lippershey was a Dutch eyeglass maker who invented the telescope and sometimes credited with the invention of the microscope. When Lippershey saw two children playing with the lenses he noticed that when they looked through two lenses it made an object appear much larger. He then tried it himself, he then placed a tube between the two lenses to make a telescope. -
Johannes Kepler
Johannes Kepler defended the idea that the planets revolve around the Sun, he also discovered that that the planets paths were not perfect circles. His descriptions of how the planets move became known as Kepler’s Laws. Today, these laws not only describe how the planets move they also determine the orbits of space stations and satellites. -
Glileo
Galileo was a Italian scientist and scholar Galileo made pioneering observations that laid the foundation for modern physics and astronomy. In July 1609, Galileo learned about the telescope, he soon developed one of his own. Galileo observed the moon and found out that Venus had phases like the moon, proving that the planet revolved around the sun. He also discovered that Jupiter had its own moons that revolved around the planet and not Earth. -
Difference between refracting and reflecting telescopes
When it comes to telescopes, there are two types; the reflecting and refracting telescopes. The distinction between the two is in how they manipulate the incoming light in order to magnify the image. The main component in a reflecting telescope is a mirror where the light will bounce off and is then focused into a smaller area. In contrast, a refracting telescope uses lenses that focus the light as it travels towards the other end. -
Giovanni Cassini
Cassini was the first to discover that their was space between the rings of Saturn in 1675. The gap between the A ring and B ring is still known today as the Cassini Division. He was the first to to accurately measure the rotational period of Jupiter. In 1662 he published measurements of the sun’s motions through the sky and came within 7% of the distance between Earth and the Sun. He is credited with giving the most accurate dimensions of the Solar System at that time. -
Sir Issac Newton
Isaac Newton’s most famous work was the three laws of motion. His first law states how objects move at the same velocity unless acted upon by another force. His second law provided a calculation for how forces interact. The third law states that for every action in nature, there is an equal and opposite reaction. Newton calculated the universal laws of gravity. -
William Herschel
William Herschel was the founder of sidereal astronomy for the systematic observation of the heavens. He discovered the planet Uranus, hypothesized that nebulae are composed of stars, and developed a theory of stellar evolution. -
Percival Lowell
Percival Lowell was a American astronomer who predicted the existence of a planet beyond the orbit of Neptune. Initiated the search that ended in the discovery of the planet Pluto. -
Karl Jansky
Karl Jansky was an American engineer whose discovery of radio waves from a extraterrestrial source inaugurated the development of radio astronomy, a new science that from the mid-20th century greatly extended the range of astronomical observations. -
Edwin Hubble
Edwin Hubble was an American astronomer who, in 1925 was the first to demonstrate the existence of other galaxies other than the Milky Way. He then demonstrated that the universe was expanding, then formulated Hubble’s Law to show that other galaxies are moving away from the Milky Way at a speed directly proportional to to their distance from it. -
Albert Einstein
Albert Einstein formulated the theory of relativity which revolutionized modern astrophysics. He is best known for his Theory of Relativity and the concept of mass-energy equivalence. He made some essential contributions to to the early development of the quantum theory. -
Sputnik
Any series of 10 artificial Earth satellites whose launch by the Soviet Union beginning on Oct. 4 1957, integrated the space age. Sputnik 1, the first spaceship launched by man. It achieved an Earth orbit with apogee and perigee. Circling Earth every 96 minutes and remaining in orbit until 1958. -
Ejnar Hertzsprung
Ejnar Hertzsprung was a Danish astronomer who classified types of stars by relating their color to their absolute brightness. The Hertzsprung-Russell diagram was named partially after him. In 1913 he established the luminosity scale of Cepheid variable stars, a tool measurement for intergalactic distances. -
Yuri Gagarin
Yuri Gagarin was the first person to fly into space. His flight, on April 12, 1961, lasted 108 minutes as he circled Earth for a little more than one orbit in the Soviet Union’s Vostok spacecraft. Following the flight, Gagarin became a cultural hero in the Soviet Union. -
The Apollo Program
NASA’s Apollo Program consisted of 17 missions in the 1960s and 1970s to send the first humans to the moon. The program used the mighty Saturn V rocket to launch three astronauts on Apollo spacecraft. Later missions included a Lunar Module for moon landings. It was NASA’s apollo 11 mission in 1969 that landed the first astronauts on the moon. Apollo spacecraft also flew astronauts to NASA’s Skylab space station. -
1981 First Space Shuttle Flight
The first launch of the Space Shuttle occurred on 12 April 1981, exactly 20 years after the first manned space flight, when the orbiter Columbia, with two crew members, astronauts John W. Young, commander, and Robert L. Crippen, pilot, lifted off from Pad A, Launch Complex 39, at the Kennedy Space Center. -
1996 Mars Pathfinder Expedition
Launched on December 4, 1996 by NASA aboard a Delta II booster a month after the Mars Global Surveyor was launched, it landed on July 4, 1997 on Mars Ares Vallis, in a region called Chryse Planitia in the Oxia Palus quadrangle. The lander then opened, exposing the rover which conducted many experiments on the Martian surface. The mission carried a series of scientific instruments to analyze the Martian atmosphere, climate, geology and the composition of its rocks and soil. -
1997 Cassini Orbiter
Launched aboard a Titan IVB on October 15, 1997, Cassini was active in space for nearly 20 years, with 13 years spent orbiting Saturn, studying the planet and its system after entering orbit on July 1, 2004.The voyage to Saturn included flybys of Venus, Earth, the asteroid 2685 Masursky, and Jupiter. Its mission ended on September 15, 2017. -
Neil Armstrong 1969
At 10:56 p.m. EDT, American astronaut Neil Armstrong, 240,000 miles from Earth, speaks these words: “That's one small step for man, one giant leap for mankind.” Stepping off the lunar landing module Eagle, Armstrong became the first human to walk on the surface of the moon. -
John Glenn 1962
February 10, 1962, John Glenn became the first American to orbit the Earth on this date. In 4 hours and 56 minutes, he circled the globe three times in his space capsule Friendship 7. He reached speeds of more than 17,000 miles per hour (27,000 km/hr). The successful mission with a splashdown and recovery in the Atlantic Ocean, 800 miles (1,300 km) southeast of Bermuda. -
Super Blue Moon Eclipse
On January 31, the full moon will be a supermoon, when the lunar orb is relatively close to Earth and so appears bigger and brighter than average. And since the second one in the month, it will also be what’s known as a blue moon.
