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322 BCE
Aristotle
384-322 BC
Aristotle believed in a geocentric universe and that the planets/ stars were perfect spheres but earth wasn't. He thought that the movements of the planets and stars must be circular because then they could go on forever. He believed the earth was the center of the universe. Now we know that some of his beliefs were wrong but he was very well respected and helped us learn how our solar system is made up and how our planets/ stars are made up. -
168
Ptolemy
100-168 AD
Ptolemy believed the earth was the center of the universe. Even though he had an incorrect theory he worked to prove it. So, he started studying the planets. He believed that planets must move in epicycles, smaller circles, and that the Earth moved along an equant. None of this was true but he made us look farther into space and he made us look farther into how our solar system was set up. -
1543
Copernicus
1473-1543 AD
Copernicus had a heliocentric system. He used his own observations of the movements of our planets to support his theory. He believed that the earth rotated on an axis and that the sun was the center of our solar system. He also believed that earth and all of our other planets orbited around the sun. Copernicus did not have tools to prove his theory but later on Galileo found proof. Copernicus showed us how our solar system really worked and answered many questions. -
Tycho Brahe
1546-1601 AD
Tycho Brahe made important contributions to the telescope. He proved that comets were atmospheric phenomena. He showed that comets created a change in the celestial sphere he concluded that the stars were so far away that their parallax was too small to measure. Yet Tycho Brahe believed that the stars were closer than we think. He taught us new things on how the solar system worked and we learned new things on stars and comets. -
Hans Lippershey
1570-1619 AD
Hans Lippershey was the inventer of the first telescope and he helped with the invention of the compound microscope. Hans Lippershey wanted to learn more about space and our solar system so he invented the telescope to look more into the solar system. He gave us new understandings of the solar system and answered many different unknown questions. -
Johannes Kepler
1625-1712 AD
Johannes Kepler discovered 3 major laws of planetary motion. These were laws describing the motions of planets in the solar system. (1) the planets move in elliptical orbits around the sun (2) the time to travel any arc of a planet's orbit is the same as central body and that area law. (3) this is the same relationship between the planet's periodic times and their orbits. With theses laws we had a better understanding of our solar system. -
Galileo
1564-1642 AD
Galileo had his own idea on how motion really worked he devised a telescope that could enlarge objects up to 20 times. He built the first telescope used for astronomy. He was able to use this telescope to prove the truth of the Copernican system of heliocentrism. Other scientists, such as Sir Isaac Newton and Johannes Kepler, were able to learn even more about the ways of the world and the solar system. -
difference between refracting and reflecting telescopes
Refracting and reflecting telescopes use different methods to boost light from dim objects into the sky. Refractor Telescopes have 2 lenses. One gathers light from a distant object and focuses in on it. The second (the eyepiece) enlarges the focused image. Reflector Telescopes use 2 mirrors instead of 2 lenses. Light from an object enters the telescope and reflects off a mirror at the end of a tube. The second mirror is in the middle of the tube and reflects this image to the eyepiece. -
Giovanni Cassini
1625-1712 AD
Giovanni Cassini observed saturn's moons. And began studying rotational periods of planets in Italy. He determined the inclination of the Earth’s orbit by the diameter of the sun and the refraction of light in the Earth’s atmosphere. Cassini determined the rotation of Jupiter. He also determined the rotation of Venus and Jupiter. He gave us a better understanding of our planets -
Sir Issac Newton
1643-1724 AD
Sir Issac Newton discovered 3 new laws of motion (1) objects stay in motion unless hit by another object. (2) force equals mass times acceleration. (3) for every action, there is an equal and opposite reaction. This gave us knew understandings in the laws of motion. -
William Herschel
1738-1822 AD
William Herschel discovered the planet Uranus in 1781. This was the first planet to be discovered since prehistoric times. Herschel discovered over 4,600 nebulae and created. Herschel built some of the most powerful telescopes. William Herschel emphasized different stars densities. He interpreted different stars surrounding planets. He discovered most of our planets in our solar system. -
Percival Lowell
1855-1916 AD
Percival Lowell is the founder of the Lowell Observatory in Flagstaff, Arizona which was meant to observe mars. He believed in the theory of canals on the planet Mars. He was first to realize the possibility of a ninth planet beyond Neptune. He believed that was creating anomalies. Made us look further into our solar system. -
Karl Jansky
1905-1950 AD
Karl Jansky wanted to improve radiotelephone service so, he began building an antenna to receive radio signals. Within months Jansky discovered the time it takes for the stars to rotate across the sky. He later was able to determine rotations of other planets. Some even outside of the milky way galaxy. He gave us knew understandings of space. -
Edwin Hubble
1889-1953 AD
Edwin Hubble found the Cepheid variable star. That proved that there were other galaxies in space beside the Milky Way. Another thing Hubble discovered was that galaxies move away from each other at a constant rate. He also created a classification system which divides galaxies into three classes: ellipticals, lenticulars, and spirals. Edwin Hubble's discoveries taught us more about our universe and different galaxies. -
Albert Einstein
1879-1955 AD
Albert Einstein proved Newton right about most of his theory's but, was wrong about gravity. Einstein had a theory on relativity that the laws of physics are the same for observers, and that the speed of light in a vacuum was separate of the motion of all observers. Einstein's theory of gravity was that massive objects cause a distortion in space-time, which is felt as gravity. He proved his theories and changed the way we think about space. -
Sputnick
1957 AD
Sputnick is any of a series of 10 artificial Earth satelites. Sputnick 1 achieved earth orbit circling it every 96 minutes. Sputnick 2 was the first to carry a living dog into space and circle the earth. Sputnick gave us new information on our universe. -
John Glenn
1921-2016 AD
John Glenn was a NASA astronaut who became the first American to orbit the earth and the oldest human ever to travel into space. He never landed on the moon but completed 3 orbits of earth in 5 hours. -
Ejnar Hertzsprung
1873-1967 AD
Ejnar Hertzsprung showed that a relationship exists between the colours of the stars and their brightness. He also showed that giant dwarf stars must exist. The correlation of colour became the basis of a method called spectroscopic parallaxes of stars. That estimates their distance from earth. He taught us things we never knew about stars before. -
Yuri Gagarin
1934-1968 AD
Yuri Gagarin was the first man to fly into space. He spent several years working on designing a reusable spacecraft for the Soviet Union which launched from the Baikonur space station. His flight orbited earth once. It lasted just under 2 hours. He showed it was possible for people to travel into space. -
Neil Armstrong
1930-2012 AD
Neil Armstrong was a NASA astronaut who stepped out of the lunar lander Eagle and was the first man to set foot on the surface of the Moon. His actions were the purpose of years and years of research and development. When Neil Armstrong set foot on the moon he said "It's one small step for man, one giant leap for mankind". -
The Apollo Program
1963-1972 AD
The Apollo Program was created by NASA and was committed to landing the first astronauts on the moon. The program finally succeeded in 1970. The Apollo Program had 17 missions leading up to landing on the moon. Apollo 7 and 9 were orbit flight tests, Apollo 8 and 10 orbited the moon. The rest of the missions (except 13) landed on the moon. The Apollo Program gave us new information/understandings on the moon. -
The first space shuttle flight
1981 AD
The first space shuttle flight was called the Space Shuttle Enterprise, it happened a year after the first space shuttle was made. The first space shuttle flight occurred on April 12, 1981 with two crew members, astronauts John W. Young, commander, and Robert L. Crippen, pilot. This was the first time ever that a spacecraft was shot into space with people on it. This was a huge accomplishment for NASA and the U.S. -
Mars Pathfinder Expedition
1996 AD
Mars Pathfinder Expedition was launched December 4, 1996 and landed on Mars on July 4, 1997. It was designed as a technology demonstration as a new way to transfer lander and the first ever robotic rover to the surface on mars. Pathfinder reached it's goal but also returned a lot of data and lasted longer than predicted. Both the lander and the rover carried instruments for scientists and provided engineering data to NASA. Such as instruments for atmosphere, climate, geology. -
Cassini Orbiter
1997 AD
The Cassini Orbiter was launched into space with tons of different instruments to accurately measure conditions in the atmosphere. It reached Saturn and it's moons in 2004, and collected data to understand Saturn's system. The Cassini Orbiter equipped 27 science investigations.It communicated back to NASA with an antenna. It also calculated measurements from a distance such as changes in the environment. The Cassini Orbiter gave us new information on Saturn. -
New Horizons
2006-2019 AD
New Horizons is a NASA spacecraft that was the first to visit Pluto in July 2015. It launched January of 2006. New Horizons collected data from Pluto such as photos of it's surface. It reached an object in the Kuiper Belt, called 2014 MU69 in January of 2019. Along New Horizons way to Pluto it passed Mars, Jupiter, Saturn, Uranus, and Neptune collecting data along the way. New Horizons gave us new information on our solar system that we never knew before.
