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322 BCE
Aristotle
Aristotle believed that the Earth was geocentric, or the center of the solar system and that the Earth was round. However, during a lunar eclipse (when the Earth is between the Sun and the Moon), the shadow on the moon is round, which means that Earth is round. Lunar eclipses gave ancient astronomers such as Aristotle more opportunities to understand the world and the solar system than just realizing the Earth is round. -
168
Ptolemy
Ptolemy came up with an idea, about how the universe works and how the planets and stars move known as the Ptolemaic System. The main idea of the Ptolemaic System was that Earth was the center of the universe and all of the other planets, stars and the Sun revolved around it. This idea was how people thought of the universe for 1400 years. -
1543
Copernicus
Copernicus believed that the sun was the center of the universe and that planets revolved in perfect circles. The idea of the sun being the center was called heliocentric. His idea also claimed that the Earth's rotation accounted for the rising and setting of the Sun and the movement of the stars not that the Sun and stars moved around Earth. -
Tycho Brahe
Tycho Brahe didn't believe in a heliocentric universe instead he believed in a universe were the Moon and Sun revolved around the Earth and the other 5 known planets revolved around the Sun. He also worked on developing new astronomical instruments and in measuring and fixing the positions of stars . -
The difference between refractoring and reflectoring telescope
A reflector telescope uses two mirrors and refractor uses two lenses. The mirrors in the reflector bounce light and image into the eyepiece. The refractor lenses work by the first one captures the light and images and bounces it to the second lense where the image is magnified and bounced to the eyepiece. -
Hans Lippershey
Hans had made the first telescope. He claimed that his telescope could magnify objects to make the object look 3 times closer. No one knows who actually invented the telescope but rumors have it that Hans did. -
Johannes Kepler
Kepler believed in a heliocentric universe.Kepler had three laws for planetary motion. The first laws is that the planets move around the sun in an elliptical orbit. The second laws is that a radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time. The third is that the squares of the sidereal periods (of revolution) of the planets are directly proportional to the cubes of their mean distances from the Sun. -
Galileo
Galileo supported the heliocentric universe. He built a telescope off of the idea of the spyglass. Using this telescope he discovered that Venus had phases just like the moon. This supported the idea of the heliocentric universe. He also discovered 4 of Jupiter's moons. -
Giovanni Cassini
He discovered the Cassini Division, the dark gap between the rings A and B of Saturn. He discovered four of Saturn's moons. he was also one of the first astronomers to study zodiacal light. -
Sir Isaac Newton
He created the three laws of motion. When he was studying the laws of modern physics he resulted in creating the formulation of the law of universal gravitation. Universal Gravitation is statement that any particle of matter in the universe attracts any other with a force varying directly as the product of the masses and inversely as the square of the distance between them -
William Herschel
He discovered the planet Uranus, hypothesized that nebulae are composed of stars, and developed a theory of stellar evolution. He was the founder of sidereal astronomy for the systematic observation of the heavens.he created the theory of the evolution of stars and theory of the structure of nebulae. -
Ejnar Hertzsprung
He classified types of stars by relating their color to their absolute brightness.he showed that a relationship exists between the colors of the stars and their true brightness and that giant and dwarf stars must exist. The correlation of color with true brightness became the basis of a widely used method of deducing the so-called spectroscopic parallaxes of stars (estimates of their distances from the Earth). -
Percival Lowell
Lowell predicted the existence of a planet beyond the orbit of Neptune and initiated the search that ended in the discovery of Pluto. He also studied Mars. He championed the now-abandoned theory that intelligent inhabitants of a dying Mars constructed a planet-wide system of irrigation, utilizing water from the polar ice caps, which melt annually. Turns out the canals he say were just his eyelashes on the telescope. -
Karl Jansky
Jansky discovery of radio waves from an extraterrestrial source inaugurated the development of radio astronomy, a new science that from the mid-20th century greatly extended the range of astronomical observations. After months of study he discovered that the source of the unidentified radio interference came from the stars. After this he did not pursue the further development of radio astronomy. -
Edwin Hubble
Hubble worked in the field of extragalactic astronomy and is generally regarded as the leading observational cosmologist of the 20th century. When Hubble was studying he found Cepheid variable stars in the Andromeda Nebula, a very well-known spiral. The fluctuations in light of these stars enabled Hubble to determine the nebula’s distance using the relationship between the period of the Cepheid fluctuations and its luminosity. The Hubble space telescope was named after him. -
Albert Einstein
Einstein's work helps astronomers study everything from gravitational waves to Mercury's orbit. He also is known for his work on general relativity and the photoelectric effect. Einstein showed that physical laws are identical for all observers. However, the speed of light in a vacuum is always the same, no matter at what speed the observer is travelling. This work led to his realization that space and time are linked into what we now call space-time. -
Sputnik
Sputnik, any of a series of 10 artificial Earth satellites whose launch by the Soviet Union beginning on Oct. 4, 1957, inaugurated the space age. Sputnik 1, the first satellite launched by man into orbit was a 184-pound capsule. It achieved an Earth orbit. -
Yuri Gagarin
Gagarin Soviet cosmonaut who in 1961 became the first man to travel into space. Gagarin’s 4 3/4-ton Vostok 1 spacecraft was launched on April 12, 1961, orbited Earth once in 1 hour 29 minutes at a maximum altitude of 187 miles. -
John Glenn
Glenn was the first U.S. astronaut to orbit Earth, completing three orbits in 1962. Glenn flew on the Mercury-Atlas 6, and on February 20, 1962, his space capsule, Friendship 7, was launched from Cape Canaveral, Florida. Its orbit ranged from approximately 161 to 261 km (100 to 162 miles) in altitude. -
Neil Armstrong
Armstrong was a U.S. astronaut, and the first person to set foot on the Moon. On July 16, 1969, Armstrong, blasted off in the Apollo 11 towards the moon. -
Apollo Program
The Apollo program was designed to land humans on the Moon and bring them safely back to Earth. Six of the missions (Apollos 11, 12, 14, 15, 16, and 17) achieved this goal. Apollos 7 and 9 were Earth orbiting missions to test the space crafts. Apollos 8 and 10 tested elements of space flight while orbiting the Moon, and returned photography of the lunar surface. Apollo 13 didn't land on the Moon due to a malfunction, but also returned photographs. -
First Space Shuttle Flight
The first space shuttle flight took off on April 12, 1981. Its name
was Space Shuttle Columbia, or STS-1.The shuttle was humankind's first re-usable spacecraft. The shuttle would launch like a rocket and land like a plane. The two solid rocket boosters that helped push them into space would also be re-used, after being recovered in the ocean. Only the massive external fuel tank would burn up as it fell back to Earth. It was all known as the Space Transportation System. -
Mars Pathfinder Expedition
Mars Pathfinder was launched December 4, 1996 and landed on Mars' Ares Vallis on July 4, 1997. It was designed as a technology demonstration of a new way to deliver an instrumented lander and the first-ever robotic rover to the surface of Mars. Pathfinder didn't only accomplished this goal but also returned a huge amount of data and outlived its design life. -
Cassini Orbiter
Cassini-Huygens was one of the most ambitious missions ever launched into space. Its mission was to get to Saturnian system ( Saturn, it's rings, and it's moons) for astronomical information on the beautiful gas giant. It's loaded with an array of powerful instruments and cameras, the spacecraft was capable of taking accurate measurements and detailed images in a variety of atmospheric conditions and light spectra. -
Total Solar Eclipse
Scientifically Total Solar Eclipse is also called Umbra.The Moon is 400 times closer to the sun and in the total solar eclipse Moon covers the whole Sun into its crescent. The conditions in the path of totality can change frequently making air temperature drop with an immediate effect of making the area of darker.The moon completely obscures Sunandonly solar corona is visible during this astronomical events. If any planet exists at the time of Solar Eclipse they can be seen as a point of light. -
The Difference Between Reflectors and Refractors in Telescopes
The difference between a reflecting and refractoring telescope is that the reflector uses two mirrors and the refractor uses two lenses. The reflector mirrors bounce the light and image to the eyepiece where it can be seen. The refractor lenses work by the first lenses grabs the light and image and the second lenses inlarges the image and bounces it into the eyepiece where it can be seen.
