History of Astronomy

Aristotle

384 BCE

Greek astronomer that believed that the earth was spherical along with other planets. And that earth was the center of the universe. He believed that the sun and moon orbited the earth. Also believed that the planets were connected to an invisible shell surrounding earth that moved.

Hipparchus

190 BCE

Greek astronomer and mathematician that calculated the distance from the earth to the moon.

Ptolemy

100

Wrote a book called the Almagest that was a catalog of stars and eclipses.

Copernicus

1473

Formulated a heliocentric model of the universe in which the sun is centered instead of the earth.

Tycho Brahe

1546

A Danish astronomer that believed the moon orbited the earth. Had the most comprehensive and accurate space timings of his time.

Galileo

1564

An Italian that discovered Jupiter's moons, Io, Europa, Callisto Ganymede. Studied gravity velocity, and fall speed. Same as heliocentric. Discovered sunspots and proved stars aren't fixed to invisible shells.

Hans Lippershey

1570

First to apply for a patent for a telescope, 3x magnification, lens maker.

Johannes Kepler

1571

Tycho Brahe’s assistant. Discovered that the orbit of the planets are not circular, but elliptical. (oval)

Refracting telescope

1608

Uses a lens as its objective to form an image rather than a curved mirror.

Giovanni Cassini

1625

Italian who discovered 4 new moons orbiting saturn, noted the divisions of rings for Saturn, and the rotation periods of Mars and Jupiter.

Sir Isaac Newton

1642

Formulated the 3 laws of motion, built the first reflecting telescope and furthered developed the works of copernicus and kepler.

Reflecting telescope

1668

Uses a curved mirror to reflect light and form an image rather than a lens.

William Herschel

1738

Pioneered the use of astronomical spectrophotometry, discovered Uranus and its moons, 2 more of Saturn's moons found polar ice on mars leading to studies to find water on mars, and that the nebulae in the Messier catalog were clusters of stars.

Percival Lowell

1855

Speculated that there are canals on mars and discovered Pluto.

Ejnar Hertzsprung

1873

Danish chemist that developed the Hertzsprung–Russell diagram. determined the distances to several Cepheid variable stars.

Albert Einstein

1879

Developed the theory of relativity and gravitation, discovered the law of the photoelectric effect, made the concept of mass energy.

Edwin Hubble

1889

American discovered the universe is expanding using the color of the stars. Hubble’s law, galaxies are moving away from each other. The basis of the Big Bang Theory.

Karl Jansky

1905

American discovered radio waves emanating from the Milky Way.

John Glenn

1921

First American to orbit the Earth. (3 times) In 1961

Neil Armstrong

1930

First man on the moon in 1968

Yuri Gagarin

1934

A Soviet pilot and cosmonaut. He was the first human to journey into outer space and orbit earth.

Sputnik

1957

The first ever satellite that was made by the Soviet Union that put the Soviet Union ahead of the United States. Science and space travel became a new priority for the U.S. and the educational system. In 1958 President Dwight Eisenhower created NASA and began the Space Race.

Apollo Missions

1963

Missions directed towards getting on the moon and getting back safely.

First space shuttle flight

1981

(AKA STS-1) First American manned space flight since 1975

Mars pathfinder expedition

1996

The first robotic rover on Mars.

Cassini Orbiter

1997

Orbiter named after the person who discovered Saturn. An orbiter of Saturn.

SpaceX Falcon Heavy

2018

The most powerful rocket in the world. Heavy lift launch vehicle that took a Tesla Roadster to space.