Lillquist, History of Astronomy

Aristotle

384 BCE

384-322, Aristotle believed in geocentric Universe and that the planets and stars were a perfect sphere but Earth was not, rather Jagged or crooked. He thought the stars must go on forever, since they are circular.

Ptolemy

168

100-168, Ptolemy created the Ptolemaic system, which stated that the Earth is always stationary, which other planets (Sun, moon, etc.) travel around the Earth in a "Uniform Motion."

Copernicus

1543

1473-1543, Copernicus mostly believed like Ptolemy, that the Earth held it's center, while the sun, moon etc. revolted around it.

Tycho Brahe

1601

1546-1601, Tycho helped overturn the belief heliocentric where the sun is in the center. ( Basically the opposite of geocentric ) He believed that Earth was motionless at the center of the universe though, other than moving.

Hans Lippershey

1619

1570-1619, Hans Lippershey, first person to apply a patent on the telescope, claiming that items could magnify a persons view by looking into the scope. Soon Galileo heard about this and designed a better one the next few days without even seeing one before.

Johannes Kepler

1630

1571-1630, Johannes Kepler created the 3 laws of planetary motion which laws are stated to be, "1. Planets move in orbits shaped like an ellipse. 2. A line between a planet and the Sun covers equal areas in equal times, and number 3. How long a planet takes to go around the Sun is related to the radius of the planet’s orbit." Kepler's laws of planetary motion is describing the motions of the planets in the solar system.

Galileo

1642

1564-1642, Galileo believed most that all things revolted around Earth, and was the first to discover craters on the moon and sunspots. He also discovered the four most massive moons of Jupiter, known as Io, Ganymede, Europa and Callisto.

Giovanni Cassini

1712

1625-1712, Giovanni Cassini discovered four of Saturn's moon, Iapetus, Rhea, Tethys, and Dione, which he called Sidera Lodoicea.

Sir Isaac Newton

1724

1643-1724, Sir Isaac Newton was the first to formulate the law of universal gravitation. Basically states that every object in the universe attracts to every other object with a force.

William Herschel

1822

1738-1822, William Herschel was interested in telescopes when he grew up and created one with a magnifying power of 6,450, which then discovered Uranus and two moons, Titania and Oberon.

Percival Lowell

1916

1855-1916, Percival Lowell predicted the existence of a planet beyond Neptune, also initiated a search but ended with the discovery of Pluto.

First Space Shuttle Flight

1918

1918, the first space shuttle flight to take place in the world. The Shuttle was in Columbia when liftoff, the space shuttle was called STS-1

Karl Jansky

1950

1905-1950 Karl Jansky developed the radio telescope. A radio specialized to receive waves from astronomical waves.

Edwin Hubble

1953

1889-1953, Edwin Hubble discovered 1373 Cincinnati (His only asteroid discovery) which states that, "The X-type asteroid has an extremely inclined, cometary-like orbit of 39 degrees to the ecliptic."

Albert Einstein

1955

1879-1955, Albert Einstein created a famous equation known today as E = mc2, shows that energy and mass are interchangeable.

Sputnik

1957

1957, The first artificial satellite launched called Sputnik-1 made by Mikhail Tikhonravov. At 184 pounds, Sputnik-1 orbited the earth every 90 minutes.

John Glenn

1962

1921-2016, John Glenn made the first 3 orbits around Earth with friendship 7, a space pod. Unlike Yuri who had made only 1, this was the first time man had orbited 3 times around.

Ejnar Hertzsprung

1967

1873-1967, Ejnar created the luminosity scale of Cepheid Variable stars, a tool to measure intergalactic distances.

Yuri Gagarin

1968

1934-1968, Yuri Gagarin flew out on the first trip to space on April 12, 1961. Lasting 108 Minutes, Yuri circled the Earth. Yuri Gagarin had been the first person in space, and had been a Soviet Hero.

Neil Armstrong

1969

1930-2012, Neil Armstrong was the first man to ever land on the moon, with Apollo 11, Neil Armstrong had successfully took his first walk on the moon.

The Apollo Program

1972

1963-1972, the Apollo Program was created in 1963, and the goal was to make 11 spaceflights and a walk on the moon, and their goal was achieved, Neil Armstrong was the first to ever do that.

Mars Pathfinder Expedition

1996

1996, the Mars Pathfinder Expedition began, a rover had been released on mars designed to demonstrate a way to deliver and instrumented lander.

Cassini Orbiter

1997

1997, Cassini Orbiter flew into space, used for taking exact measurements and pictures of different planets etc.

Difference Between Refracting And Reflecting Telescopes

2019

The difference between refracting and reflecting telescopes is that refracting telescopes use lenses while reflecting uses a mirror that helps eliminate the risk of chromatic aberration.