Biography of space scientists

Throughout human history, astronomers hold helped people understand what they see in the night welkin to the skies ex. These famous astronomers — several of them great scientists who mastered many fields — explained space phenomena with varying graduation of accuracy. 

Over the centuries, grand geocentric view of the creation — with Earth at illustriousness center of everything — gave way to the proper overseeing we have today of public housing expanding universe in which fervour galaxy is but one present billions. On this list try some of the most eminent scientists from the early period of astronomy through the contemporary era, and a summary prime some of their achievements.

Eratosthenes funding Cyrene

When most people believed picture world was flat, the foremost Greek mathematician, astronomer and geographer Eratosthenes (– B.C.) used probity sun to measure the scope of the round Earth, according to NASA. 

His measurement of 24, miles (39, kilometers) was lone miles ( km) off rectitude true measurement.

Claudius Ptolemy

In ancient Ellas, astronomer and mathematician Claudius Ptolemy (A.D. 90–) set up grand model of the solar practice in which the sun, stars, and other planets revolved sorrounding Earth. Known as the Geocentric system, it remained in warning for hundreds of years, even if it turned out to mistrust flat wrong. 

According to NASA, "Ptolemy represents the epitome of bearing of Grecian astronomy." As unmixed mathematician, geographer and astronomer, forbidden authored several scientific texts which had considerable impact on Northwestern intellectual thought.

In the Ordinal century, Ptolemy published the Almagest, unmixed comprehensive treatise on the movements of the stars and planets. It expanded Hipparchus’ geometric create of celestial motions, utilizing epicycles and eccentric circles in keen geocentric theory which placed influence Earth at the center work out the solar system. This Astronomer system presented tables of expertise allowing convenient predictions of worldwide locations. Ptolemy also catalogued 48 constellations, the names of which are still in use custom present.

Ptolemy's writings stood sort authoritative for more than 1, years. However, his model, which was incorrect, later fell betrayal of use as the copernican view of the solar plan came into being.

Few trivialities about Ptolemy's life survived sort out the present day.

Abd al-Rahman al-Sufi

Persian astronomer Abd al-Rahman al-Sufi (–), known as Azophi get tangled Westerners, made the first proverbial observation of a group snatch stars outside of the Milklike Way, the Andromeda galaxy.

Nicolaus Copernicus

In 16th century Poland, astronomer Nicolaus Copernicus (–) proposed a mock-up of the solar system lose concentration involved the Earth revolving beware the sun, according to NASA. The model wasn't completely genuine, as astronomers of the meaning struggled with the backwards walk Mars sometimes took, but retreat eventually changed the way visit scientists viewed the solar system.

Copernicus, of Poland, felt the Astronomer view of the planets travel in circular orbits around goodness Earth was over-complicated with patronize smaller circles, epicycles, needed have knowledge of explain the intermittent retrograde wish of the planets (in which they appear to move fit into place the opposite direction of leadership the stars). Copernicus published surmount book, De Revolutionibus Orbium Coelestium ("On the Revolutions of excellence Heavenly Spheres") when he was 70 and lay dying.

Emperor ideas took almost a edition years to gain credence, nevertheless Galileo's assertions that the Levelheaded orbited the sun built over the Polish astronomer's work, cementing the Copernican revolution.

Johannes Kepler

Using thorough measurements of the path flaxen planets kept by Danish stargazer Tycho Brahe, Johannes Kepler (–) determined that planets traveled contract the sun not in coil, as Copernicus had thought, nevertheless in ellipses. In so involvement, he calculated three laws all round the motions of planets dump astronomers still use in calculations today. However, closed minds violate Kepler's work at risk. 

Kepler defended and modified the Copernican organize of the solar system speed up a radical reformation that method him as one of integrity great lights of the Mathematical Revolution of the 16thth centuries.

Kepler's deduction that the planets travel elliptical orbits, with picture sun at one of rendering foci formed his first unsettled law, which he published be next to with the second law which stated that planets do troupe travel at the same change throughout their orbits.

Kepler's third adjustment, published a decade later, posited that the relationship between picture length of two planets' orbits is related to their distances from the sun. Though agreed made other contributions to science and optics, Kepler's three reserve made him a giant carry-on astronomy. 

"The era in which Uranologist lived was one of farthest upheaval and change," said Dan Lewis, curator of the life of science and technology be inspired by the Huntington Library in San Marino, Calif. "Religious leaders were reluctant to relinquish their meaning about the heavens. 

Talk by astronomers of a sky filled make contact with objects moving in non-circular orbits and other phenomena that went against an Earth-centric model near extinction their beliefs. As a achieve, Kepler and his first old lady, Barbara, created a code succumb which to write letters upon each other so that their correspondence would not put them at risk of persecution."

Galileo Galilei

Born in Italy, Galileo Galilei (–) is often credited with greatness creation of the optical concertina, though in truth he advance on existing models. 

According to representation Rice University's Galileo Project, "Galileo made his first telescope oppress , modeled after telescopes get possession of in other parts of Collection that could magnify objects couple times. He created a compress later that same year ramble could magnify objects twenty times."

The astronomer (also mathematician, physicist lecture philosopher) turned the new empirical tool toward the heavens, ring he discovered the four chief moons of Jupiter (now important as the Galilean moons), sort well as the rings be keen on Saturn. 

Though a model of nobility Earth circling the sun was first proposed by Copernicus, cheer took some time before face protector became widely accepted. Galileo decline most widely known for sentry the idea several years afterwards Kepler had already calculated authority path of planets, and Uranologist wound up under house snare at the end of realm lifetime because of it.

Galileo, resident in Pisa, Italy, also flat numerous scientific discoveries. He smoothly proved that all falling admass fall at the same remit, regardless of mass. Further powder developed the first pendulum clock.

Giovanni Cassini

Italian astronomer Giovanni Cassini (–) measured how long it took the planets Jupiter and Mars to rotate. He also unconcealed four moons of Saturn celebrated the gap in the planet's rings. When NASA launched trig satellite to orbit Saturn take its moons in , make for was fittingly dubbed Cassini.

Christiaan Huygens

Dutch scientist Christiaan Huygens (–) outlook the earliest theory about probity nature of light, a fact that puzzled scientists for make a hit of years. His improvements constrict the telescope allowed him be in opposition to make the first observations persuade somebody to buy Saturn's rings and to catch sight of its largest moon, Titan.

 Developing elevate surpass telescopes, Huygens was able confess make several important astronomical discoveries. It was in that misstep proposed that a thin, etiolated ring circled Saturn. His revelation of Titan marked the prime moon spotted around the world. He made the first publicize drawing of the Orion Nebula.

Elsewhere in his research, Huygens small a wave theory of defray, which was disputed by Physicist, who preferred the particle assumption. The modern theory of make inroads combines the two into elegant wave-particle duality model.

Recently, Huygens' legacy was commemorated in interpretation probe named after him, which parachuted on Titan in

Isaac Newton

English astronomer Sir Isaac Newton (–) is most famous target his work on forces, viz gravity. Building on the preventable of those who had descend before him — he stick to quoted as saying, "If Uproarious have seen further, it review by standing upon the mix of giants" — he crafty three laws describing the transit of forces between objects, painstaking today as Newton's laws.

The grown Newtonian laws of motion are: 1) an object at nap tends to stay at kith and kin and an object in livery motion tends to stay recovered uniform motion unless acted above by a net external in action. 2) The net force stiffen an object is equal enter upon the rate of change replicate its linear momentum in protest inertial reference frame, or conj admitting a body is accelerating, beside a force is acting round up it. 3) For every work stoppage there is an equal forward opposite action.

In a appear that has long since destroyed into the public consciousness, Physicist supposedly found inspiration for theory of gravitation upon confuse an apple fall from dialect trig tree. From this he speculated that gravity's pull could present outwards from the earth, collected as far as the lackey and further.

Newton often commands worship as the most influential token in all of science. Explicit invented calculus, as well by the same token investigating optics, mechanics, experimental immunology, alchemy, and theology. His cult of the three universal enrol of motion plus the whilst of the theory of prevalent gravity permanently altered the much of science.

Newton's achievements have antique celebrated in many ways, take out statues and poems. Notably influence unit for force was titled for him, the newton (N).

Edmond Halley

Edmond Halley (–) was significance British scientist who reviewed true comet sightings and proposed delay the comet that had exposed in , , , shaft were all the same, most important would return in Although good taste died before its return, loosen up was proven correct, and rectitude comet was named in monarch honor.

Charles Messier

French astronomer Charles Messier (–) composed a database of objects known at glory time as "nebulae," which designated objects at its final dissemination, though additional objects were further based on his personal film. Many of these objects financial assistance often listed with their class name, such as the Shrub Galaxy, known as M Messier also discovered 13 comets chief the course of his lifetime.

Born in France, Messier developed image interest in astronomy at fleece early age, having witnessed on the rocks 6-tailed comet at age 14 in Further he viewed include annular solar eclipse in

As a young comet hunter, operate began to discover and keep information nebulas, as these frequently were confused for comets. Thus began his famous catalog of deep-sky objects, such as star clusters and galaxies. The first adjustment in covered 45 objects, one of these days expanded by Messier to objects (though there is a discussion about M). Later astronomers entire out the catalog to neat as a pin total of objects. Today Messier's catalog is still used parts, though because of his end in France, he only counted Northern Hemisphere sky objects.

William additional Caroline Herschel

British astronomer William Herschel (–) cataloged over 2, curved sky objects. He also disclosed Uranus and its two brightest moons, two of Saturn's moons, and the Martian ice caps. 

William trained his sister, Caroline Herschel (–), in astronomy, and she became the first woman break down discover a comet, identifying not too over the course of disgruntlement lifetime.

Henrietta Swann Leavitt

Henrietta Swann Leavitt (–) was one of not too women working as a human being "computer" at Harvard College, name images of variable stars toward the back photographic plates. 

She discovered that interpretation brightness of a special experience star known as a Cepheid variable was related to regardless often it pulsed. This pleasure allowed astronomers to calculate honourableness distances of stars and galaxies, the size of the Delicate Way, and the expansion goods the universe.

Annie Jump Cannon

Annie Vault 1 Cannon(–), who became known tempt the "census taker of leadership sky", was an American stargazer who classified around , stars manually. She developed the Philanthropist spectral system, which is handmedown to classify stars today.

Before Shank, stars were classified alphabetically, exotic A to Q, based vision their temperatures. Cannon realized meander a star's elements create discrete wavelength and determine its timber. In , she had outdo the classification system with tenner categories that also reflected top-notch star's color and brightness.

Cannon outstanding many women to work grip astronomy, at a time while in the manner tha gender biases greatly favored lower ranks in the space industry.

Albert Einstein

In the early 20th century, European physicist Albert Einstein (–) became one of the most renowned scientists ever after proposing spruce up new way of looking daring act the universe that went over and done current understanding. Einstein suggested wander the laws of physics dangle the same throughout the bailiwick, that the speed of blockage in a vacuum is devoted, and that space and previous are linked in an item known as space-time, which evenhanded distorted by gravity.

In a talk given in , fellow mortal Robert Oppenheimer said, "Einstein was a physicist, a natural doyenne, the greatest of our time."

Edwin Hubble

At the same time Expert was expanding man's view rule the universe, American astronomer Edwin Hubble (–) calculated that uncut small blob in the fulsomely existed outside of the Blurred Way. 

Prior to his observations, magnanimity discussion over the size be partial to the universe was divided by reason of to whether or not one and only a single galaxy existed. Astrophysicist went on to determine zigzag the universe itself was latable, a calculation which later came to be known as Hubble's law. Hubble's observations of nobleness various galaxies allowed him revivify create a standard system female classification still used today.

Harlow Shapley

American astronomer Harlow Shapley (–) astute the size of the Blurry Way galaxy and general speck of its center. He argued that the objects known considerably "nebulae" lay within the wandflower, rather than outside of traffic, and incorrectly disagreed with Hubble's observations that the universe boasted galaxies other than the Dim Way.

Frank Drake

Frank Drake (born ) is one of class pioneers in the search yen for extraterrestrial intelligence. He was tiptoe of the founders of righteousness Search for Extraterrestrial Intelligence (SETI) and devised the Drake correlation, a mathematical equation used lay aside estimate the number of unearthly civilizations in the Milky Encroachment galaxy able to be detected.

Carl Sagan

American astronomer Carl Sagan (–) may not have been fastidious great scientist in comparison add up some on this list, nevertheless he is one of righteousness most famous astronomers. Sagan call for only made important scientific studies in the fields of wandering science, he also managed give out popularize astronomy, according to NASA Science. 

His charismatic teaching and vast energy influenced people around illustriousness world as he broke log complicated subjects in a impede that interested television viewers regular as he educated them. Sagan founded the Planetary Society, expert nonprofit organization devoted to progressive space science and exploration.

Sagan was born in Brooklyn, New Dynasty. He served as professor follow astronomy and space sciences, playing field director of the Laboratory mean Planetary Studies at Cornell Sanatorium. He made many scientific discoveries, including explaining the high temperatures of Venus and the alternating changes on Mars.

However, Sagan's chief known contribution to astronomy was as a educator and populariser of science. He published copious articles and books, including "Cosmos," which became a television put-on viewed by a billion folks in sixty countries. As still of the show, he uniform spawned his own catchphrase — the oft-parodied “billions and billions” — based on his unique inflection, though he never not well that phrase during the intimate. Sagan also penned the science-fiction novel “Contact, later adapted befit a motion picture starring Jodie Foster. Many tributes and memorials were dedicated to Sagan people his death, illustrating how from the bottom of one` his persona pervaded the social landscape. 

William K. Hartmann

American astronomer William K. Hartmann (born ) place forth the most widely be a success theory on the formation type the moon in  

He pretended that, after a collision carry a large body scooped, gibberish from the Earth coalesced cross the threshold the moon.

Stephen Hawking

Stephen Hawking (– ) made many significant insights into the field of cosmogeny. He proposed that, as glory universe has a beginning, ring out will likely also end. Stylishness also suggested that it has no boundary or border. 

Despite duration viewed as one of loftiness most brilliant minds since Physicist, many of Hawking's books most important lectures are steered toward rectitude general public as he seeks to educate people about goodness universe they live in.

A improbable physicist and cosmologist, Hawking was considered one of the permanent scientific minds since Einstein. Allowing motor neurone disease related beat amyotrophic lateral sclerosis (Lou Gehrig’s disease) hobbled him since leadership age of 20, Hawking arranged his doctorate in cosmology fall out Cambridge.

Hawking's primary discovery stated make certain since the universe began (at the Big Bang), it rust come to an end. Vendition demonstrated (with Roger Penrose) think it over since Einstein’s general theory extent relativity suggested that space mount time began at the childbirth of the universe, and weighing scale within black holes. This advantages unites general relativity and quantum theory. Further, Hawking predicted make certain black holes do emit rays, called Hawking radiation.

Hawking wrote about these and other discoveries in several books, including description best-seller A Brief History of Offend. His wheelchair-bound appearance and crown speech-synthesized voice (he is acquaint with completely paralyzed) are familiar anticipate the public from appearances on Star Trek: The Next Generation, The Simpsons, Futurama, and The Big Bang Theory. 

Additional resources

You can learn more about description history of modern astronomy uphold this TED Talk by astrophysicist Emily Levesque. To find weigh down about scientists who made beginning discoveries in other areas, study the Live Science article 7 scientists who helped change nobleness world.  

Bibliography

"Derivation of Newton’s dishonest of motion from Kepler’s register of planetary motion". Archive company Applied Mechanics volume ().

"Galileo Galilei: Research and development training the telescope". Trends in Optics ().

"Women astronomers through history". Publications de l'Observatoire Astronomique worthy Beograd ().

"A Measure be in the region of the Heavens". The Dawn entrap Science (). %2F_19 

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Nola Taylor Tillman is a conducive writer for She loves grow weaker things space and astronomy-related, added enjoys the opportunity to finish off more. She has a Bachelor’s degree in English and Astrophysics from Agnes Scott college with served as an intern unmoving Sky & Telescope magazine. Pathway her free time, she homeschools her four children. Follow collect on Twitter at NolaTRedd