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384 BCE
Aristotle
384-322 BC. Aristotle had two observations that supported the idea that the Earth was the center of the universe. He had made the geocentric model. He opened a school. -
100
Ptolemy
100-168 - Ptolemy. Ptolemy had made the mathematical model of the universe. He stated that earth was stationary and at the center of the universe. His first major astronomy work was the Almagest which contains reports of observations that he made over the preceding quarter of a century. -
1473
Copernicus
1473-1543. Nicolaus Copernicus discovered and proposed that the planets revolve around the sun when everyone else believed that all other planets revolved around the sun. Other scientist have built on his idea of this and there was a model of the universe. -
1546
Tycho Brahe
1546-1601 Tycho Brahe. He was an astronomer and writer known for his accurate and comprehensive astronomical and planetary observations. He used instruments to measure and fix the positions of the stars. This was a big change since they didn't have telescopes yet. -
1564
Galileo
1564-1642 Galileo. Galileo proved the law of motions for scientists and had improvements on the telescope which helped better understanding of the world and universe. He also worked with pendulums and steady motions. -
1570
Hans Lippershey
1570-1619 Hans Lippershey. Lippershey had invented the telescope in 1608 which was helpful to astronomers to understand the universe in a better way and observe the stars. -
1571
Johannes Kepler
1571-1630 Johannes Kepler. Kepler discovered three major laws of planetary motion. The planets move in elliptical orbits with the Sun at one focus. 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. And there is an exact relationship between the squares of the planets’ periodic times and the cubes of the radii of their orbits. -
Difference between refracting and reflecting telescopes
The refracting telescope was invented in 1608 and the reflecting telescope was invented in 1668. A reflector telescope uses two mirrors instead of two lenses. Isaac Newton developed this telescope to combat chromatic aberration. Light from an object enters the telescope tube and is reflected off a curved mirror at the end of the tube. -
Giovanni Cassini
1625-1712 Cassini. Astronomer Giovanni Cassini is associated with a number of scientific discoveries and projects, including the first observations of Saturn's moons. he was the first one to discover the first estimation of the dimensions of the solar system. Other accomplishments of Cassini include being the first to observe four of Saturn's moons, Lapetus, Rhea, Tethys and Dione which he called Sidera Lodoicea, or Louisian Stars, after the French king. -
Sir Issac Newton
1643-1724 Issac Newton. Sir Isaac Newton contributed significantly to the field of science over his lifetime. 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. He determined the three laws of motion for the universe. -
William Herschel
1738-1822 Herschel. He discovered the planet Uranus, and developed a theory of stellar evolution. In order to interpret the differences between these star clusters, it was natural for William to emphasize their relative densities. In 1785 he developed a cosmogony, a theory concerning the origin of the universe. The stars originally were scattered throughout infinite space, in which attractive forces gradually organized them into even more fragmented and tightly packed clusters. -
Percival Lowell
1855-1916 Lowell. When the red planet drew closest to Earth, Lowell decided to build an observatory. In search of the ideal place to study Mars, he selected Flagstaff, Arizona, where the high altitude, thin atmosphere and remote location would give him a good view of the planet. Soon after his observations, Lowell announced his discovery of canals and oases on Mars. The long straight lines he sketched and described were not natural features but channels of water made by dying civilization. -
Ejnar Hertzsprung
1873-1967 Hertzsprung. An astronomer who classified types of stars by relating their color to their absolute brightness.This was an accomplishment of the importance of astronomy. He showed that a relationship exists between the colors of the stars and their true brightness and that giant and dwarf stars must exist. He came up with the HR diagram. Hr diagram classifies the temperature of the stars compared to the luminosity of the stars. -
Albert Einstein
1879-1955 Einstein. Einstein made vain attempts to unify all the forces of the universe in a single theory, which he was still working on at the time of his death. His equation that helped explain special relativity, E = MC^2 – is famous even among those who don't understand the underlying physics. He also is known for his work on general relativity and the photoelectric effect. -
Edwin Hubble
1889-1953 Hubble. Edwin Powell Hubble made several significant discoveries that changed how scientists viewed the universe.Hubble noticed a pulsating star known as a Cepheid variable inside each one. Cepheid's are special because their pulsation allows for precise measurements of distance. Hubble calculated how far away each Cepheid lay, and how far to each nebula, and realized they were too distant to be inside of the Milky Way. -
Karl Jansky
1905-1950 Jansky. He was an american engineer whose discovery of radio waves from an extraterrestrial source inaugurated the development of radio astronomy, a new science that from the mid-20th century greatly extended the range of astronomical observations. He built a linear, directional antenna by which he was able to identify all the sources of interference except one. After months of study he discovered in 1931 that the source of the unidentified radio interference came from the stars. -
John Glenn 1962
1921-2016 Glenn. 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. The successful mission concluded with a splashdown and recovery in the Atlantic Ocean, 800 miles southeast of Bermuda. -
Neil Armstrong 1969
1930-2012 Armstrong. On July 20, 1969, American astronaut Neil Armstrong stepped off the lunar landing module Eagle, and became the first human to walk on the surface of the moon. Nearly 240,000 miles from Earth, Armstrong spoke these words to more than a billion people listening at home: "That's one small step for man, one giant leap for mankind." Along with Michael Collins and Edwin E. Aldrin, he was part of NASA's first manned mission to the moon. -
Sputnik
1957 Sputnik. Sputnik 1 was about the size of a basketball and weighed about 180 pounds. It was equipped with two radio transmitters and four long antennas that broadcasted a constant beep while circling the Earth for 21 days. Sputnik's launch stunned the world and changed it, too. It created an identity crisis in the United States, led to the creation of NASA and began a flurried race between the world's two superpowers to place a human on the moon. Sputnik touched all walks of life. -
Yuri Gagarin
1961 Gagarin. Yuri Gagarin was the first man in space. His flight lasted 108 minutes when he circled Earth for a little more then one orbit. Following the flight, Gagarin became a cultural hero in the Soviet Union. Even today, more than six decades after the historic flight, Gagarin is widely celebrated in Russian space museums, with numerous artifacts, and statues displayed in his honor. -
1972 The Apollo Program
1963 Apollo Program.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. Apollos 8 and 10 tested various components while orbiting the Moon, and returned photography of the lunar surface. Apollo 13 did not land on the Moon due to a malfunction. -
1981 First Space Shuttle flight
1981 Space Shuttle. On April 12, 1981, twenty years ago today, the space shuttle orbiter Columbia became the first shuttle to orbit the Earth. Columbia was launched again seven months later becoming the first piloted reusable orbiter. The oldest operating shuttle orbiter, Columbia's 1981 debut was followed by Challenger in 1982. -
1996 Mars Pathfinder Expedition
1996 Mars Pathfinder. The Mars Pathfinder mission was an important first step in rovers for NASA. The 1997 mission included the first successful rover on Mars, called Sojourner, which was delivered to the surface by the Pathfinder lander. One of the mission's innovations was Pathfinder's landing system. Rather than using conventional rockets to touch down on the surface, NASA decided to use a cocoon of airbags. After going through the higher parts of the atmosphere. -
Cassini orbiter
1997 Cassini orbiter. Cassini-Huygens was one of the most ambitious missions ever launched into space. Loaded with an array of powerful instruments and cameras, the spacecraft was capable of taking accurate measurements and detailed images in a variety of atmospheric conditions and light spectra. Equipped to thoroughly investigate all the important elements that the Saturn system may uncover, many of the instruments had multiple functions. -
Current event (Farthest object discovered in space)
Ultima Thule is the farthest space object that humans have ever seen up close. It's so far from Earth it takes more than 6 hours for signals to travel at the speed of light to reach the Earth. At 4 billion miles from Earth, Ultima Thule is the farthest-away body in space scientists have ever viewed up close. It is a door to future exploration in a mysterious, unknown region. However, it is also a time capsule from the era when the planets formed, it could contain how Earth came to be.
