Layton History of Astronomy timeline

Aristotle lived from 384-322 BC and is sometimes known as the grandfather of science. Aristotle was a student at Plato's Academy. He then opened his own school and taught students of his own. Aristotle spent much time in Athens studying, teaching, writing, and working. He believed that all stars and planets were a perfect sphere except for Earth. Aristotle then thought that since stars and some planets were round, they would move in a circular motion therefore being able to go on forever.

Ptolemy lived from 100-168. Ptolemy was an astronomer and a mathematician. He believed in a theory called the "geocentric" theory. This theory stated that Earth was the center of the universe. Because Ptolemy was a mathematician, he was able to predict the movements of the planets by using geometry. To make sure that his predictions were correct, he worked out that Earth moves in epicycles (small circles). The "geocentric" theory has been a flawed theory and was excepted for many centuries.

Nicolaus Copernicus lived from 1546-1601. He came up with a unique way of looking at our universe. Copernicus's heliocentric system put the Sun in the center of our universe and that Earth was to spin on an axis and revolve around the sun. Even though Copernicus got all of the credit for this theory, there were starwatchers who also believed in the heliocentric system. Copernicus had different ideas but were to big for scholars to study so they only study part of the ideas.

Tycho Brahe lived from 1546-1601 and was a Danish nobleman. Brahe believed in both ideas of the geocentric and the heliocentric theory's. He then made models of both theory's. Brahe discovered that the geocentric model was wrong and then only believing the the heliocentric theory. Brahe recorded Mars motions and made one of the best measurements that were actually correct. He concluded that the Earth was either motionless at the center of the universe or the stars were to far away to measure.

Galileo lived from 1564-1642. Galileo was very smart and had his own ideas on how motion worked but opposed what Aristotle had taught. He was able to use a telescope that made an object in 20 times larger to prove that Copernicus's heliocentric theory was correct. Once his observations were published, people found that they were against the church. Galileo was then sentenced to jail for his life. Other scientists then studied his observations and were able to learn way more about the world.

Hans Lippershey lived from 1570-1619. Hans was a Dutch eyeglass maker. He invented the telescope and some inventors gave him the credit of creating the compound microscope. When two children were playing in his lens workshop, they held up two different lens to their eyes. They discovered that the vane on top of the church looked either zoomed in or zoomed out with a different lens. Lippershey tried it himself and was amazed. He then stuck the lenses in between a tube and created the telescope.

Johannes Kepler lived from 1571-1630 and was a German astronomer. He believed in the heliocentric theory. He discovered the three major laws of planetary motion. 1) the planets move in elliptical orbits with the Sun at one focus 2) the time necessary to traverse any arc of a planetary orbit is proportional to the area of the sector between the central body and the arc 3) there is an exact relationship between the squares of the planets’ periodic times and the cubes of the radii of their orbits.

$Refracting and Reflecting Telescopes$

The refracting telescope was created in 1608 by Galileo and the reflecting telescope was created in 1688 by Sir Isaac Newton. The refracting telescope has two lenses. One collects the light from objects and bends it into a single point of focus, while the other lens enlarges an image. The reflecting telescope uses mirrors instead of lenses. the light from an object enters the telescope and bounces off of the first mirror then to the second and then the image is reflected onto the eyepiece.

Sir Isaac Newton lived from 1643-1742. He was an English mathematician, physician, astronomer, and author. He is famous for discovering the three laws of motion and gravity. When Newton was sitting underneath an apple tree, one feel on his head and then came up with the idea of gravity. Also, when Newton was holding up a prism to sunlight, a ray of colors came down. The colors were red, orange, yellow, green, blue, and violet. He was the first one to understand the rainbow and it's colors.

Giovanni Cassini lived from 1652-1712. He was a great astronomer, mathematician, and engineer. He was involved in many great discoveries. For example, he was the first to discover that Saturn has four moons, Lapetus, Rhea, Tethys, and Dione. In addition he took part credit in finding the big red spot on Jupiter and observed the different rotations on Jupiter's atmosphere. Cassini also discovered how far away Mars was from Earth.

William Herschel lived from 1738-1822. He was a British-German astronomer and composer. William Herschel used the telescope for many of his discoveries. These discoveries included the finding of our planet Uranus along with two of it's moons and two of it's satellites, the discovery of the satellite Mimas and Enceladus of Saturn, the discovery of the first shape description of our milky way, the discovery that Mars's atmosphere is very thin, and used the word asteroid for small planets.

Percival Lowell lived from 1855-1916. He was an American businessman, author, mathematician, and astronomer. Lowell is also the founder of the Lowell observatory in Flagstaff, AZ. Because he founded the Lowell observatory and predicted that there was another planet beyond Neptune, he is given partial credit for the founding of Pluto 14 years after his death. He is most famous for the idea that Mars has canals. This gives scientist another clue that there was once life on Mars.

Ejnar Hertzsprung lived from 1873-1967. Hertzsprung was a Danish chemist and astronomer. He classified different stars by relating their color to their absolute brightness. In 1913 he created the luminosity scale of Cepheid variable stars, which is a tool for measuring intergalactic distances. Hertzsprung is best known for his diagram that he created with Henry Russel called the HR diagram. This diagram shows the difference between stars magnitudes and their stellar classifications.

Albert Einstein lived from 1879-1955. Einstein in known for one of the most influential scientists of the 20th century. Einstein also found that light speed travels in a vacuum. It goes 300,000,000 km/sec. The equation to figure this out was E= mc2 even though not all people understood physics, it still became famous. Two most famous discoveries from Einstein are special relativity (space time structure) and general relativity (gravitation).

Edwin Hubble lived from 1889-1953. While looking at images of NGC 6822, M33 and M31, Hubble noticed a pulsating star (Cepheid variable) inside each one. Hubble calculated how far away each Cepheid lay and found that they were too distant to be inside of the Milky Way. Astronomers realized that the nebulae were in fact galaxies like the Milky Way, containing billions of stars. Hubble also discovered that galaxies are actually moving and going away from earth and are moving at 90 million mph.

Karl Jansky lived from 1905-1950. Jansky was an American physicist and radio engineer. In 1931, he discovered radio waves emanating from the Milky Way. Jansky built an antenna designed to receive radio waves. Jansky got three types of static from the antenna. 1.close thunderstorms 2.far thunderstorms 3.faint steady hiss- unknown origin. Jansky studied the third static and found out that it was the radiation coming from the Milky Way and was strongest in the center, constellation Sagittarius.

John Glenn lived from 1921-2016. Glenn was one of NASA's original Mercury astronauts. His flight on the spacecraft Friendship 7 on Feb. 20, 1962, proved to the world that America was a serious contender in the space race with the Soviet Union. That day, he orbited the earth three times in less then five hours. When he was launched on Oct. 29, 1998, he was 77 and that made him the oldest human to go into space. He was the also the first astronaut to experience a control system failure.

Neil Armstrong lived from 1930-2012. Neil was an American astronaut and aeronautical engineer. On July 20, 1969, Apollo 11 landed on the moon and was commanded by Neil Armstrong. He was the first man to ever walk on the moon. When he first got out, Armstrong radioed back down to earth with his famous line, "That's one small step for a man, one giant leap for mankind." He went up to the moon with Buzz Aldrin and they both collected samples to bring back down to earth.

Yuri Gargain lived from 1934-1968. Gargain was the first person ever launched into space. He launched on April 12, 1961. He lasted in space for 108 minutes just orbiting the earth in the Soviet Union's Vostok spacecraft. When he landed, he became a hero to the Soviet Union and an international superstar. Six decades after the flight, he was put all over Russian museums with artifacts, many of his trophy's, and his statues.

Sputnick lived from 1957-****. The Sputnick is a type of satellite that was the size of a beachball and only weighed 183.9 lbs The satellite changed the world when it was launched on October 4, 1957 by the Soviet Union. It was the world's first artificial satellite and took only about 98 minutes to orbit around earth. As a technical achievement, the Sputnik caught the world's attention and got the American public off-guard. Because the Sputnick launched, it led to the creation of NASA.

The Cassini Orbiter launched in 1957. The Cassini Orbiter was one of the most ambitious missions ever launched to space.Because it was loaded with an array of powerful instruments and cameras, the spacecraft could take great measurements and detailed images of the atmospheres conditions and light spectra. It was sent to Saturn to gather data and information. It sent valuable information back down to Earth. The spacecraft had discovered many things. For example, it found four of Saturn's moons.

The Apollo Program lasted from 1963-1972. This program was designed by NASA. Their goal of this program was to have spacecrafts go to the moon and come back successfully. There were 11 flights in total. Four of the flights were to test the equipment and six of the seven other flights landed on the moon. While this program lasted, 12 astronauts walked on the moon including Neil Armstrong who was the first.

The first space shuttle flight launched in 1981. The space shuttle was called Columbia and was the first shuttle to fly into space. John Young commanded and Bob crippen piloted the mission. The shuttle was humankind's first re-usable spacecraft. The orbiter would launch like a rocket and then land like a plane. The two rocket boosters that helped them into space would also be re-used, after the recover in the ocean. Only the massive external fuel tank would burn up as it fell back to Earth.

The Mars Pathfinder Expedition launched in 1996 and landed on Mars' Ares Vallis on July 4, 1997. The mission was relatively inexpensive and it tested out many of the technologies build into later missions, like the Mars Exploration rovers. The purpose of the Pathfinder was to prove that the concept of “faster, better and cheaper” missions could work. One example of what the robot has discovered was proof that there was once water. This means that there could have once been life on that planet.

Our universe has many stars, galaxies, planets, e.t.c. On January 31, 2019, some of NASA's scientists discovered a brand new galaxy. This galaxy's name is called Bedin 1. When a group of astronomers were taking a picture of the globular star cluster called NGC 6752, the telescope captured a never before seen galaxy. located behind the star cluster. The newly found galaxy is only 30 million lightyears away from earth.