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322 BCE
Aristotle
(384 BCE - 322 BCE) Aristotle was a ancient philosopher and astronomer. He was one of the few scientists that thought that earth is round. With Ptolemy, he believed in a geocentric universe where the planets revolves around the sun. He also discovered celestial bodies which is a naturally occurring physical structure that exists in space. -
168
Ptolemy
(100 - 168) Ptolemy is an Egyptian astronomer, mathematician, and geographer. He believed that the earth was the center of the universe. Ptolemy created the geocentric model which was a model of space where the other planets were revolving around the earth. -
1543
Copernicus
(1473 - 1543) Copernicus believed in a heliocentric universe. A heliocentric universe is the theory that all the planets revolve around the sun. He also suggested that Earth's rotation was the reason for the sun rising and the sun setting , the star movement, and that the cycle of seasons was caused by Earths revolution around the sun. -
Tycho Brahe
(1546 - 1601) Brahe was an astronomer who believed in a geocentric universe. He He also made some of the most accurate observations of positions of the planets which would soon be useful to the other believers of geocentrism. He also helped in measuring and fixing the positions of the stars. -
Hans Lippershey
(1570 - 1619) Lippershey was a spectacle maker from the United Netherlands. He was credited with inventing the refracting telescope because he was the first to try to get a patent for the design. -
Johannes Kepler
(1571 - 1630) Kepler discovered the laws of planetary motion. The laws describe the motion of planets around the sun or how the planets move around the sun in elliptical movements. Elliptical movements are movements around the sun but in an circular rotation. Mars was appearing to be moving backwards but Kepler figured out that planets travel in huge circles known as eclipses. -
Galileo
(1564 - 1642) Galileo improved the refracting telescope and invented the thermometer. He also studied the pendulum and discovered that the periods did not depend on the arc of the swing. He then had the idea of a pendulum clock. He then discovered Jupiter's four moons. When NASA sent a satellite to Jupiter they named the mission Galileo. -
Difference between refracting and reflecting telescopes
The refracting telescope was invented in 1608, and the reflecting was invented in 1668. The difference is that a reflector telescope uses two mirrors instead of two lenses.The mirror on a reflecting telescope can be fixed onto a metal plate, reflecting telescopes can be much bigger than the refractor telescope. Reflecting telescopes are cheaper to make and buy. -
Giovanni Cassini
(1625 - 1712)Cassini was a mathematician, an astronomer, and an engineer. He discovered all 62 of Saturn's moon's and divided its rings into 2. That's how people got the name for the "Cassini Division". The Cassini Spacecraft orbited Saturn in 2004 and the mission ended in 2017 by the spacecraft plunging down. The mission discovered that Saturn has water jets. Thanks to him we have been curious about Saturn and now more things about the planet are being discovered. -
Sir Isaac Newton
(1643 - 1724) Newton was a mathematician. He developed the three laws of motion which form the principles of physics. His discovery of calculus lead to more ways of solving mathematical problems. He was also famous for his 3 laws of gravitation that explained gravity. -
William Herschel
(1738 - 1822) William Herschel was an astronomer. He discovered what he first thought to be a comet, but he later found out it was the planet Uranus. He had also viewed the Orion Nebula. A nebula is a cloud of gas and dust in outer space, visible in the night sky. Herschel also made and believed the theory of stellar evolution. Stellar evolution is the process by which a star changes over the course of time. -
Percival Lowell
(1855 - 1916) Lowell was an astronomer, author and mathematician who founded the Lowell Observatory in Flagstaff Arizona. He looked at mars with a telescope and saw possible to be canals. Then other astronomers looked at mars with more advanced telescopes and discovered Lowell was not right. -
Karl Jansky
(1905 - 1950) Jansky was an American astronomer, engineer, and physicist. He discovered radio waves which developed radio astronomy and that unidentified radio interference came from the stars.The telescope was named the Hubble telescope and had to be flown into space to see because most telescopes from earth ground can not look through the atmosphere. -
Edwin Hubble
(1889 - 1953) Hubble was an American astronomer and before his discovery's, people believed that that the milky way was the only galaxy. He discovered there was more than one. He also knew the universe is expanding based on the level on redness in light coming from the galaxy. -
Albert Einstein
(1879 - 1955) Einstein came up with an equation that will help astronomers estimate the distance between a star and earth. He created the theory of relativity which revolutionized modern astrophysics. Astrophysics are the branch of astronomy concerned with the physical nature of stars. He also proved that mass and energy are equal. -
Sputnik
Sputnik was the first artificial satellite that was successfully placed to orbit the Earth. It was launched at Tyratuam in Kazakhstan. Sputnik burned up in the atmosphere. A month after the launch of that satellite, a second was sent up containing Laika. It orbited for five hours and died from overheating.As of today, Sputnik is destroyed and is not orbiting the earth anymore. -
Yuri Gagarin
(1934 - 1968) Gagarin was the first human to ever go into outer space. His mission was called Vostok 1. He orbited around the earth once in his Vostok spacecraft and it took him 108 minutes to do so. Gagarin became a cultural hero in the Soviet Union. -
John Glenn
(1921 - 2016) Glenn's flight was called Friendship 7. The tests for the automatic control system went badly. Glenn experienced nearly 9,000 hours of flying time,in about 3,000 jets. He then had around a 5 hour flight in a real space shuttle. Glenn is still the oldest person to fly into space at 77 years old. -
Ejnar Hertzsprung
(1873 - 1997) Hertzsprung is a danish astronomer and identify stars based on their color and brightness . The color and brightness became a method to measure the distance from earth. He believed the red stars are small and were the coolest. The blue stars were the biggest and the hottest. he believed the star starts out blue and then turns into a red star over time. -
Neil Armstrong
Armstrong was an american astronaut. He was the first person to walk on the moon. He said, "That's one small step for man, one giant leap for mankind," as he stepped a foot on the moon. The mission was called Apollo 11, and the it was a success. -
The Apollo Program
The Apollo Program was made to get astronauts to the moon and back to earth safely. It was the first US human space flight program. There were 17 missions and only 6 of them were successful and the others only orbited the earth and the moon. The successful missions came back with many lunar samples. -
First Space Shuttle Flight
The shuttle flight began in Florida on April 12, 1981. NASA started to create the shuttle in 1966, when they were looking for more missions after Apollo. When the first landing on the moon happened, NASA started to really work hard on the shuttle. Because of this, the cargo bay was increasing to use for satellites. -
Mars Pathfinder Expedition
The mars pathfinder was made to give a demonstration of the technology that is needed to land a spacecraft on another planet. The lander and the river successfully touched mars.They also outlived their design lives. The lander be 3 times and the lander by 12 times. -
Cassini Orbiter
Because of the Cassini orbiter, astronomers were able to find out more advanced information about Saturn. It was the first spacecraft to orbit Saturn, land in the outer solar system, and the first to sample an extraterrestrial ocean. Cassini expanded the understanding of the different worlds where life could exist. -
Parker Solar Probe
The Parker Solar Probe was scheduled to launch on July 31, 2018. ( the date changed and it launched on August 12, 2018) NASA's Solar Probe is billed as the “mission that will touch the Sun.” Designed to study the Sun's corona, the probe will pass just 3.7 million miles from the Sun's visible surface. The Parker Solar Probe is expected to reach a speed of 200 kilometers per second, making it the fastest spacecraft on record.
