Who was the first person to orbit the earth?
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On April 12, 1961 Soviet cosmonaut Yuri Gagarin is the first person to orbit Earth. His flight in Vostok 1 lasts less than 2 hr.
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The first known telescope was built by Hannes Lippershey, a Dutch optician, in early 1608.  Other opticians followed, and he sued.  It is this lawsuit, which he won that provides the historical basis for his claim.  The first Englishman to use a telescope that we know of was Thomas Harriot, who discovered lunar craters, phases of Venus, and that there are stars the human eye cannot see.  He never published, and his work, done in August 1609, was lost until a descendent sold his desk in 1912, and the papers were found.  Galileo heard of the telescope from a former student of his living in France, and went out and made a telescope on his own, starting his observations on Nov 30, 1609.  When Kepler heard of this, he also built his own.  These were all refractors.  Isaac Newton built the first reflecting telescope in 1673.
603384
you are rght about aristotle as it was Pythagoras (you know the theorem) 570 BC who hypothesised the curvature of the earth and the heavenly bodies,later the most notable writers on the positioning and behaviour of the planets were copernicus, gallaleio, kepler and newton
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Valentina Vladimirovna Tereshkova was the first woman in space. however, on Vostok 6 in 1963
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Neil Armstrong is the first man to walk on the Moon.  However, no man has ever stayed behind on the moon, as it would be a certain death sentence.
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The first U.S. manned space mission:\n\nMission: Mercury 3 (first manned flight)\nSpacecraft Name: Freedom 7\nOccupant: Alan Shepard\nDate: 5/5/1961
871004
Ancient civilizations knew this. Observations of lunar eclipses, plus the fact that the horizon is at equal distances no matter what direction we look made this pretty obvious. The earliest were probably the Assyrians or Babylonians, who developed the first coherent astronomical systems (claims by people that the natives of India were first notwithstanding)\n\nThe issue was not the shape of the earth, but its size, and its place in the scheme of things (at the center or off to the side.) It took thousands of years to displace the earth conceptually from the center of creation to a planet orbiting a star, which was then displaced from the center of the universe to a position in an outlying arm of our galaxy, which itself was displaced from being the entire universe to being the largest galaxy and at the center of the universe to being just another galaxy among billions. So we're just a bunch of hicks from the sticks.
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The first step was to use Kepler's laws to get relative distances between the planets and the sun. So, it was known that mercury orbited at a distance of 40% of the earth's before the actual distances were known.\n\nAfter that, the actual distance to *one* object orbiting the sun was enough to give all the distances. Historically, that was done by paralax with asteroids that came close to the earth. Today it is done by bouncing radio beams off of other planets such as Venus and measuring the time it takes for the reflected beam to get back to us. Various probes also give a distance calibration.
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Kepler figured out the laws that describe planetary orbits.  This enabled much more accurate planetary positions (which Kepler published), and set the stage for Isaac Newton to explain that gravity  was the force that held the planets in their orbits.\n\nUp until Kepler, everyone was sure that planetary orbits must be some form of perfect circle. His discovery that they are actually elliptical was an important turning point in the history of science, away from the Aristotelian method of applying philosophical concepts to physical reality, and towards modern empirical science.
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matahari is right, it was Aristarchus of Samos. But his ideas were not accepted and his writings were lost. We only know about him from the writings of Ptolemy, who did not believe in heliocentrism himself. The idea was later reinvented by Copernicus, whose writings were preserved and his ideas eventually accepted.
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Ferdinand Magellan was the first to try.  The ships he commanded made it all the way, but he died en route.  Juan Sebastian Elcano took over after he died and brought the ships home, so he made it.  Garcia Jofre de Loaysa's tried a bit alter.  All of his ships sank and he died, but Fernando de la Torre and eight survivors were picked up by a Portuguese ship and made it home. The first person to plan and lead and expedition and survive it was Sir Francis Drake.
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The question doesnt make sense to me but the first person to reach the south pole was Roald Amundsen on the 14th December 1911.
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The first measurement of the equator was done by Eratosthenes of Samos--centuries ago.  He computed it as being roughly 25,000 miles, which is really quite accurate.\n\nEratosthenes was a hotshot at geometry.  He knew that on the spring equinox, the sun cast no shadow at noon in (as I recall it) Syene, Egypt (? on the spelling); in Samos, the shadow at the same time cast a shadow that made an angle of about 6 degrees with the top of the stick.  Using the known distance between the two places, the already accepted fact that the earth was spherical, and a little geometry, he figured out the equitoral diameter, and did a very fine job of it as well.\n\nHe later recomputed the figure, by the way, getting 18,000 miles.  Columbus repeated the calculation, long afterward, and got 19,400.  The Portuguese (the premier mapmakers of Columbus' day) had computed it as about 24,800 or so... They knew the world was round--and bigger than ol' Christopher Columbus thought...  An aside, but a fun one...
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He was the first to come up with a good system of classifying all life on earth. His system, with variations, is still in wide use today. \n\nVery Important Person to scientists!
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John Glenn, Jr., Astronaut / U.S. Senator \n\nBorn: 18 July 1921 \nBirthplace: Cambridge, Ohio \nBest Known As: The first American to orbit Earth
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Saturn was discovered in 1610 by the astronomer Galileo Galilei. \nYes, others had seen Saturn before him--but they didn't exactly take into account what it was. He was the first to realize that it was a planet and also other facts concerning the planet.
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stated the first version of the Law of conservation of mass, recognized and named oxygen (1778) as well as hydrogen, disproved the phlogiston theory, introduced the Metric system, invented the first periodic table including 33 elements, and helped to reform chemical nomenclature, not to mention where Mrs. Lavoisier's erogenous zones were.