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Adams, John Couch (1819-1892) English astronomer and mathematician who, at the age of 24, was the first person to predict the position of a planetary mass beyond Uranus. But, unfortunately, Adams did not publish his prediction. Galle confirmed the existence of Neptune based on independent calculations done by Le Verrier.
Aldrin, Edwin (Buzz) (1930- ) The American astronaut piloted the lunar module of Apollo 11 and on July 20, 1969, became the second man to walk on the moon. Aldrin was an engineer by training and an elder of the Presbyterian Church. In November 1966, he had made a record 5-hour space walk during the Gemini 12 mission.
Arago, Dominique François Jean (1786-1853) French astronomer and physicist and Director of the Paris Observatory, who discovered the phenomenon of the production of magnetism by rotation.
Aristarchus of Samos (about 320-250 BC) Greek astronomer who, using geometry, measured the distance between the Sun and Moon. He used this to calculate that the sun was 20 times farther away than the moon (it is actually 400 times farther). He also suggested that because the Sun was seven bigger than Earth ( it is actually 109 times bigger), Earth must travel around the Sun. It was 18 centuries before this idea started to become accepted.
Aristotle (320-250 BC) Philosopher in ancient Greece. He developed a great educational outline called “Aristoteles outline” and he is called as the “founder of universal education”. His idea of Universe was that, celestial spheres are rotating around Earth. This is called as the geocentric theory.
Armstrong, Neil (1930- ) American air force test pilot who, as commander of the Apollo 11 mission, was the first man to walk on the Moon on July 20, 1969. As he stepped onto the Moon he said "That's one small step for man, one giant leap for mankind." He left NASA in 1971 and became a university professor before going into business.
Danish astronomer who assisted Galle with the first observations of Neptune. After receiving its predicted position from Le Verier, Galle and d'Arrest began searching. With Galle at the eyepiece and d'Arrest reading the chart, they scanned the sky and checked that each star seen was actually on the chart. Just a few minutes after their search began, d'Arrest cried out, "That star is not on the map!" and earned his place in the history books.
Baade, Walter (1893-1960) Emigrating to the US from Germany in 1931, Baade worked at Mount Wilson Observatory in California and in 1948 moved to nearby Palomar Observatory. In 1943 he discovered that the universe contains two types of stars: very old ones containing few metals, and newer ones rich in metals. This also applied to the Cepheid variable stars, whose properties can be used to help calculate the size of the universe. The universe was then found to be twice as big as previously thought.
Barnard, Edward Emerson (1857-1923) American astronomer; discovered Jupiter's satellite Amalthea and Barnard's star, the second-nearest star system to the Sun.
Bessel, Friedrich (1784-1846) German astronomer who supervised the construction of a new observatory at Königsberg and became its first director in 1813. He concentrated on measuring the exact positions of stars. In 1838 he observed the slight movement of the star 61 Cygni, movement he knew to be caused by viewing it when Earth is at opposite points on its orbit around the Sun. From this, he calculated that the star was 10.3 light-years away. This was the first star to have its distance measured by parallax, and helped establish a scale for the universe.
Bode, Johann Elert (1747-1826) German astronomer, known for the bogus "Bode's Law" which attempts to explain the sizes of the planetary orbits.
Bond, William Cranch (1789-1859) One of the earliest American astronomers of note; rose from poverty and overcame a lack of formal education to become the first director of the Harvard College Observatory where he studied Saturn and (with Lassell) discovered its moon Hyperion.
Brahe, Tycho (a.k.a. Ottensen, Tyge) (1546-1601) Danish astronomer whose accurate astronomical observations formed the basis for Johannes Kepler's laws of planetary motion. At the age of 30, Brahe's astronomical talents were such that King Frederick II of Denmark gave him the Baltic island of Hven on which to build an observatory. Brahe's instruments were well made and accurate, and he measured the position of the sun Sun and planets against the stars for more than 20 years. Between 1572 and 1574, he recorded a new star - a supernova - in the distance to the great comet of 1577 and showed that it was farther away than the Moon, and that it had an elongated orbit that passed the planets. He moved to Prague in 1597 and recruited Johannes Kepler as his assistant. Kepler used Brahe's results to calculate the orbits of the planets.
Burnell, Jocelyn Bell (1943- ) British astronomer who, as a research student at Cambridge, discovered pulsars. On August 6, 1967, while observing the rapid variations in signals from radio sources and looking for quasars, she discovered an unusual radio signal consisting of a rapid series of pulses that occurred precisely every 1.337 seconds. This turned out to be a pulsating neutron star (a pulsar), a star slightly more massive than the Sun but only a few kilometers in diameter.
Cannon, Annie Jump (1863-1941) American astronomer who classified the spectra of more than 300,000 stars into a temperature sequence. She joined the staff of Harvard College Observatory in 1896 and stayed there until she retired in 1940. Her work was cornerstone of the Henry Draper Catalog of stellar spectra.
Cassini, Giovanni Domenico (a.k.a. Dominique, Jean) (1625-1712) Italian-born French astronomer. As professor of astronomy at the University of Bologna, Cassini measured the time it takes Jupiter, Venus, and Mars to spin once on their axes. He also discovered four of Saturn's satellites (Tethys, Dione, Rhea, and Iapetus) and a gap in that planet's rings. Cassini suggested that the rings were not solid but made of individual rocks. In 1669, he moved to France to help build and run the Royal Observatory in Paris. There he measured the distance between Earth and Mars and used this to calculate the Sun-Earth distance. However, he refused to accept that Earth went around the sun or that gravity was universal. Both his son and grandson became directors of the Paris Observatory.
Chandrasekhar, Subrahmanyan (1910-1995) Indian-born astrophysicist who studied astronomy in Madras and England before moving to the US in 1936. He received the 1983 Nobel Prize for Physics for his work on dying stars. Chandrasekhar realized that a white dwarf star with more than 1.4 times the Sun's mass could stop shrinking: It would become a neutron star or a black hole.
Discoverer of Pluto's moon Charon.
Clarke, Arthur C. (1917- ) In 1945, this British science fiction writer suggested that a satellite in geostationary orbit, 35,800km above Earth, would be useful for communications. One satellite above the Atlantic could be used to transmit TV and telephone signals between Europe and North America. The technology was not available then, but geostationary satellites are now commonplace.
Copernicus, Nicolaus (1473-1543) Polish astronomer who advanced the heliocentric theory that the Earth and other planets revolve around the Sun. This was highly controversial at the time as the Ptolemaic view of the universe, which was the prevailing theory for over 1000 years, was deeply ingrained in the prevailing philosophy and religion. (It should be noted, however, that the heliocentric idea was first put forth by Aristarchus of Samos in the 3rd century BC, a fact known to Copernicus but long ignored.) Copernicus studied mathematics and classics in Poland and law and astronomy in Italy. He returned to Poland in 1506 to become a canon at Frauenberg Cathedral, a post he held until he died. His duties were light and he devoted most of his time to astronomy. By about 1513 he had realized that Earth was not the center of the universe or even of the solar system. Earth, which went around the Sun, was not special as had been thought, but merely one of a collection of planets. He was aware that his idea went against the teachings of the church, and his book De Revolutionibus Orbuim Coelestrium was not published until he was on his deathbed.
Drake, Frank (1930- ) American radio astronomer who, in 1960, pioneered the use of radio telescopes to listen for signals from extraterrestrial life. In 1974 this project continued with the use of the Arecibo radio telescope in Puerto Rico. Drake also devised an equation to estimate how many communicating technological civilizations there might be in the Galaxy at any one time.
Eddington, Arthur (1882-1944) English Astronomer who showed how the physical characteristics inside a star can be calculated from its surface features. After studying at Cambridge, Eddington worked at the Royal Observatory in Greenwich before returning to Cambridge to become director of its observatory for 31 years. Eddington produced a model of the interior of a star, discovered the relationship between a star's mass and its luminosity, stressed that nuclear fusion produced stellar energy, and measured how much a ray of light is bent by a gravitational field. He also calculated the mass of the universe, arguing that constants, such as the velocity of light, depended on it. A skillful writer, he popularized both astronomy and Einstein's general theory of relativity.
Einstein, Albert (1879-1955) American physicist born in Germany. He was the first person to succeed in dealing the whole universe theoretically. Einstein received the Nobel Prize for Physics in 1921 for explaining how light is radiated in packets of energy called quanta, but he is best remembered for his theories of relativity. In 1905, he introduced special theory of relativity, and in 1916, introduced general theory of relativity. These showed that nothing could move faster than the velocity of light (c), that is velocity was constant, and that objects became more massive as they moved faster. Einstein found that mass (m) was equivalent to energy (E) according to his now famous equation E = mc2. He also realized that gravitational fields can bend light beams and change their wavelengths. Einstein was a life-long pacifist and in 1933 moved to America to avoid Nazi persecution as a Jew. In 1952 he turned down the offer to be president of Israel. Einstein's theory of relativity, together with Quantum theory, forms the base of present cosmology.
Eratosthenes of Cyrene (about 273-192 BC) Greek scholar who calculated the size of Earth. Born in north Africa, Eratosthenes was educated in Athens and then became librarian at Alexandria in Egypt and the tutor of the son of King Ptolemy III of Egypt. He was, among other things, a skilled geographer who calculated the curvature of Earth. He did this by measuring the length of shadow cast by the sun at two places 950 km apart. From this he estimated the circumference of Earth to be 46,500km (it is actually 40,075 km at the equator).
Eudoxus of Cnidus (about 408-355 BC) A Greek astronomer and mathematician who constructed a model of the solar system with Earth at it's center and the planets carried around Earth, supported on a series of transparent spheres. The spheres were nested inside each other, with the axis of each sphere attached to the inside of the surrounding sphere. His model was able to explain the motion of planets as viewed from Earth, but it did not account for everyday changes that occur in the distances between Earth and individual planets. It was replaced after a few centuries.
Flamsteed, John (1646-1719) As England's first Astronomer Royal, Flamsteed was in charge of the new Roayl Observatory at Greenwich near London, which opened in 1676. He used a mural arc and a sextant with telescopic sights in conjunction with the new, accurate clocks that ran for a year to produce a new catalog of 3,000 stars. This was published after he died, in 1725, and the accuracy of the star positions was 15 times better than previous catalogs. Flamsteed also made detailed studies of the shape of the orbits of both the Moon and Earth.
Fraunhofer, Joseph Von (1787-1826) A Bavarian glass and lens maker, Fraunhofer tried to make a lens that did not disperse light into its rainbow of colors. In 1814, while testing this lens, he noticed that the Sun's spectrum was crossed by numerous fine dark lines. He measured the wavelengths of 324 of the 54 lines that he could see: They are now known as Fraunhofer lines. In the 1820s he found that light could be split into colors by passing it through a grating of fine slits, and that the splitting increased as the slits were moved closer together. Gratings are now used extensively in spectroscopy.
Gagarin, Yuri (1934-1968) On April 12, 1961, the Russian cosmonaut Gagarin became the first person to fly in space. The first lasted one orbit of Earth; the Vostok 1 spaceship reached a height of 344km. Gagarin was airborne for 108 minutes before the retrorockets slowed him down and he parachuted the last 7km to the ground. He died in a plane crash while training to return to space.
Galileo Galilei (1564-1642) Astronomer and physicist from Italy. He is called as the father of modern science. By studying dynamics he approved, law of inertia, constant acceleration of falling object, and the route of a projectile are always describes a parabola. IN 1609, he invented Galilei telescope, and he was the first man to observe universe through a telescope. He found satellites of Jupiter, craters on the Moon, Blackspots on the Sun, etc. He is famous for emphasizing heliocentric theory. He became confident of his idea when he observed the motion of 4 biggest satellites of Jupiter. As professor of mathematics at the universities of Pisa and Padua, Galileo did much to disprove ancient Greek theories of physics. On learning of the invention of the telescope, he built one in 1609 and discovered that the Sun spun around every 25 days, the Moon was mountainous, Jupiter had four satellites, and Venus showed Moonlike phases. The Venus observations helped prove that the Sun and not Earth was at the center of the solar system. These revolutionary ideas, coupled with his belligerent nature and love of publicity, got him into trouble with the church, and late in life he was tried by the Inquisition in Rome and placed under house arrest.
Galle, Johann Gottfried (1812-1910) German astronomer who, with Heinrich Louis d'Arrest, made the first observation of Neptune based on calculations by Le Verrier. Though Galle was the first to observe Neptune, its discovery is usually credited to Adams (who made an earlier calculation) and Le Verrier.
Gamow, GeorgeGamow, George (1904-1968) Ukrainian physicist who in 1933 defected to the US. In 1948, with Ralph Alpher (1921- ) and Hans Bethe (1906- ), he showed how helium could be produced during the Big Bang from protons and neutrons, and how helium could combine with other nuclei to create elements. Gamow also predicted that the universe would be filled with radiation remaining from the intense temperatures that existed during the Big Bang.
Glenn, John (1921- ) In 1962, Glenn was the first American to orbit Earth; he made three orbits during a 5-hour flight. After retiring from the space program in 1964 he took up politics, and in 1974 was elected senator in Ohio. In 1998, he became the world's oldest astronaut when he flew on a space shuttle mission.
Goddard, Robert (1882-1945) Goddard was a rocket pioneer whose work was mainly ignored by his own country. From an early age he was fascinated by the idea of space travel, and he carried out experiments at Clark University in Massachusetts, where he was a research student and, for 30 years, a lecturer in physics. In 1919, he published his theories of Konstantin Tsiolkocsky two decades earlier. In the 1930s he launched his first stabilized rocket. This had a liquid-fuel motor that pumped oil and liquid oxygen into a combustion chamber. Its success attracted funding and Goddard went on to produce rockets with gyroscopic control and jet vanes.
Guth, Alan (1947- ) American particle physicist who turned to cosmology. He devised the theory of inflation in 1979, in which he proposed that just after the Big Bang the universe expanded from the size of a proton to the size of a grapefruit in a tiny fraction of a second. This both smoothed out space-time and made a universe that looks the same in all directions.
Hale, George Ellery (1868-1938) American astronomer who founded the Yerkes, Mt. Wilson and Palomar observatories. He also invented the spectroheliograph, an instrument that revealed the details of the Sun's surface. In 1904 he became the director of the Mount Wilson Observatory in California where, in 1908, he discovered that sunspots had magnetic fields, and then measured the strengths of these fields. Hale devoted much of his working life to raising funds for and organizing the building of large telescopes, including the great 5-meter telescope on Palomar Mountain in California, which was named the Hale Telescope in his honor.
Hall, Asaph (1829-1907) American astronomer who discovered the two moons of Mars, Deimos and Phobos.
Halley, Edmond (1656-1742) English astronomer who applied Newton's laws of motion to historical comet data and predicted correctly the reappearance of the comet which now bears his name. Halley did much of his research while working for the Royal Society. He was a close friend of Isaac Newton and, in the 1680s, helped him to prepare his book, Principia. IN 1698 Halley became a captain in England's Royal Navy and sailed over the north and south Atlantic measuring the deviation of the magnetic compass and hoping to invent a mechanism foe measuring longitude. Halley drew the first map of the southern sky, discovered that stars move, and realized that Earth was very old. He is best known for predicting that Halley's comet returns to the Sun every 76 years. Later in life he became professor of mathematics at Oxford and England's second Astronomer Royal.
Harrison, John (1693-1776) Harrison, a British clockmaker, introduced a pendulum that did not change length as its temperature varied, and a ratcher that kept a clock going as it was being wound up. In the early 1730s he was given money to build a clock that worked accurately when on board a ship at sea. His final precision clocks enabled a ship's longitude to be measured when out of port, and Harrison received a 20,000 prize for this. Accurate clocks are very important in astronomy for measuring the position of stars in the sky.
Hawking, Stephen (1942- ) British theoretical physicist who, even though he suffers from a severe neuromotor disease, has spent his life studying the behavior of matter close to a black hole. Astronomers used to think that nothing could escape from a black hole but Hawking showed that thermal radiation could be emitted. His Brief History of Time is one of the best-selling science books ever.
Herschel, Caroline (1750-1848) Born in Hannover, Germany, Caroline Herschel came to England in 1772 to collaborate with her brother William. She discovered eight comets between 1786 and 1797. In 1787, the British King granted her a salary to continue as assistant to her brother. She is remembered especially for her catalog of 2500 nebulas and star clusters.
Herschel, Sir William (1738-1822) British astronomer who discovered Uranus and cataloged more than 800 double stars and 2,500 nebulae. In 1757 Herschel moved from Hannover to England where he earned a living as a musician. In 1766 he was hired as an organist in Bath. There he started building telescopes and grinding their metal mirrors. In 1781, using one of his telescopes outside his house, he accidentally discovered the planet Uranus (thinking at first that it was a comet). This made him so famous that, within a year, he gave up music and became the king's astronomer. He built the largest telescope in the world, with a mirror 100cm across, and used this to survey the sky and Galaxy. He was greatly assisted by his sister Caroline. William discovered hundreds of nebulas and found that the Sun was moving toward the constellation Hercules. His son John (1792-1871) also became a famous astronomer.
Hertzsprung, Ejnar (1873-1967) Danish astronomer who devised a standard of stellar brightness, defined as the brightness stars would have if they were all 32.6 light-years away. He noticed in 1906 that standard brightness was related to the temperature of a star. This was independently discovered in 1913 by Henry Russell. The graph plotting standard brightness against temperature, the Hertzsprung-Russell diagram, is a vital tool in the study of stellar evolution.
Hewish, Antony (1924- ) English radio astronomer who studied fluctuations in radio sources and the way in which the signals from two radio telescopes can be combined to mimic a dish as large as the distance between them. In 1967, together with his student Jocelyn Bell Burnell, he discovered pulsars. he was awarded a Nobel Prize for Physics jointly with Martin Ryle, in 1974.
Hipparchus (about 190-120 BC) Greek mathematician and astronomer who invented an improved theodolite with which he measured the position of about 850 stars. He produced a catalog of these, which was still in use 18 centuries later. He also classified the stars according to how brigth they appeared in the sky. this system forms the basis for today's magnitude scale of stellar brightness. Earth's spin axis moves like that of a top as it spins, and Hipparchus measured the rate at which the axis changed position, and the way in which the distance between Earth and the Sun varies throughout the year.
Hoyle, Fred (1915- ) English astrophysicist who showed how stars could produce elements and who suggested that the universe was in a steady state. Hoyle was based at the University of Cambridge in England, but spent ten years at the Hale Observatory in California. At Hale, he collaborated with William Fowler (1911-1995), and in 1957 they showed how elements such as lithium, carbon, oxygen, and iron could be created inside stars. When large stars eventually explode as supernovas, these elements are distributed into space and are recycled in second-generation stars. In 1948 Hoyle, with Thomas Gold and Hermann Bondi, introduced the steady state theory of the universe. This theory lost ground after the discovery of the background radiation, the remnant of the Big Bang, in 1965.
Hubble, Edwin Powell (1889-1953) American astronomer whose observations proved that galaxies are "island universes", not nebulae inside our own galaxy. His greatest discovery was the linear relationship between a galaxy's distance and the speed with which it is moving. The Hubble Space Telescope is named in his honor. Hubble studied law at Chicago and in England, but on returning to the US he became an astronomer. At the Mount Wilson Observatory in California he used the new 2.5m telescope to study nebulas. He identified two types: those in our own Galaxy and those beyond. In 1924, he realized that the distant ones were separate galaxies. He also found that the fainter and more distant the galaxy, the faster it was moving away from our own Galaxy. He classified the different types of galaxies but (incorrectly) suggested that one type evolved into another as they aged.
Huggins, William (1824-1910) Until 1854 this Englishman sold dry goods, but he then left the family business to concentrate on observing the sky. He built his own private observatory in London and designed a telescope. Using this, he was able to study the composition of the Sun, Moon, planets, and stars and showed, in 1863, that universe is made of the same elements as exist on Earth. In 1868, he became the first astronomer to use the spectroscope to measure the speed with which stars are moving away from Earth. He also discovered that some nebulas are made of gas.
Huygens, Christiaan (1629-1695) Huygens was a Dutch scientist who moved to Paris in 1666 and worked there for 15 years before returning home. He produced the best telescope of his time and a new form of telescope eyepiece. In 1655 he used these to observe Saturn and discovered a large satellite that later became known as Titan. He then discovered that the planet was surrounded by a ring. Huygens also invented the pendulum clock and proposed that light was a wave motion, like sound or water.
Jansky, Karl (1905-1950) American radio engineer who was the father of radio astronomy. He set out to discover the source of interference in radio signals being used for ship-to-shore communications. In 1934 Jansky built a rotating radio antenna and receiver, and soon realized that the interference came from the constellation of Sagittarius. This is the densest part of the Milky Way, and he was detecting radiation from electrons in the Galaxy's magnetic field.
Keeler, James E. (1875-1900) American astrophysicist, probable discoverer of the dark narrow gap in the outer part of the A ring of Saturn, and the second director of Lick Observatory. Keeler was (probably accidentally) cheated of his rightful fame when the A ring gap became known as "Encke's Division". Encke had earlier seen a broad, poor contrast feature in the A-ring which is quite different from the sharp, distinct gap that Keeler recorded on the very first night of observing with the Lick 36-inch refractor. On the other hand, the gap may have been seen even earlier by Francesco De Vico, William Lassell and the Rev. William R. Dawes. The history of visual observations of gaps in Saturn's rings is very confusing.
Kepler, Johannes (1571-1630) German astronomer and mathematician. Considered a founder of modern astronomy. Kepler figured out his three laws of planetary orbits - now known as Kepler's laws of motion - using data obtained by Tycho Brahe, whom he assisted for the last few months of the Danish astronomer's life. Kepler was convinced that Brahe's observations were accurate, and persisted until he had calculated the orbits correctly. By 1609, Kepler had found that the orbits of planets were ellipses, not circles, and that the speed of a planet around its orbit was slower the farther away it was from the Sun. Kepler was a Lutheran and, because of religious persecution, had to move several times. In 1627 he published the Rudolphine Tables, which allowed astronomers to calculate the positions of planets, in the future, present, and past. Mistakenly, he suggested that planets emitted musical notes as they moved.
Korolev, Sergei (1906-1966) In 1931 this Russian engineer was a founding member of the Moscow Group for the Study of Rocket Propulsion. In World War II he was imprisoned by Stalin and put to work developing jet-assisted aircraft. After the war, he developed improved versions of captured German V-2 rockets and was responsible for the production of the first Russian intercontinental missile. He went on to design the Sputnik satellite, and the Vostok, Voskhod, and Soyuz crewed spacecraft.
Kowel, Charles T. (1940- ) American astronomer; discovered Leda and the comet-like object 2060 Chiron (a.k.a. 95 P/Chiron).
Kuiper, Gerard (1905-1973) Dutch-born American astronomer best known for his study of the surface of the Moon; discovered Miranda and Nereid, found an atmosphere on Titan. (Dr.Kuiper was solidly Americanized; his name is pronounced to rhyme with "viper.")
Lagrange, Joseph Louis (1736-1813) French (originally Italian, Giuseppe Luigi Lagrangia; born in Turin, moved to Paris and became a French citizen) mathematician and astronomer; made a number of contributions to the study of celestial mechanics.
Laplace, Pierre Simon De (1749-1827) French mathematician and astronomer who was a professor at École Militaire in Paris. Starting in 1773, he spent 13 years explaining how the variations in the orbits of Jupiter and Saturn could be accounted for within Newton's laws of gravity. In 1796 he proposed that the Sun and the solar system were formed out of a gas cloud that rotated faster and faster as it shrank, and threw off rings of material as it go smaller. These rings then formed planets. This theory of the formation of the solar system held until the end of the 19th century.
Lassell, William (1799-1880) British astronomer, discovered Neptune's largest satellite, Triton and (with Bond) discovered Saturn's moon Hyperion. A successful brewer before turning to astronomy.
Leavitt, Henrietta (1868-1921) Leavitt worked at Harvard College Observatory in Massachusetts, measuring the brightness of star images on photographic plates. For many years, she studied Cepheid variables - stars that oscillate in brightness in regular cycles - in the Magellanic Clouds. In 1912, she confirmed that the longer the cycle, the brighter the star: So by determining the length of the cycle, a star's distance could be calculated from its apparent and real magnitude. This led to the discovery that the Magellanic Clouds were about 100,000 light years away and were small galaxies beyond our own Galaxy
Lemaître, Georges (1894-1966) Belgian physicist who became a priest in 1923 and then turned to cosmology. In 1931, Lemaitre proposed that the universe was once contained in a primeval atom about 30 times the size of the Sun. This exploded into space, scattering material that then condensed to form galaxies and stars. He suggested that the movement of galaxies could be used as indicators of expansion of the universe. This later developed into the Big Bang theory.
Le Verrier, Urbain Jean Joseph (1811-1877) French mathematician whose prediction of the position of an undiscovered planet (Neptune) that caused perturbations in the orbit of Uranus was the first to be confirmed (by Johann Galle) though Adams had made a similar but unpublished prediction some months earlier.
Lovell, Bernard (1913- ) Lovell developed airborne radar for nonvisual bombing raids during World War II. In 1949 he instigated funding for a 76m radio telescope at Jodrell Bank near Manchester. Building started in 1951 and it was completed just in time to track the rocket of the first Russian satellite, Sputnik 1, in 1957. This attracted much needed funds. Lovell was director of the Jodrell Bank radio observatory for more than 30 years.
Lowell, Percival (1855-1916) American astronomer. He founded the Lowell Observatory in Arizona (1894), where his studies of Mars led him to believe that the linear markings (first noted by Schiaparelli) on the surface were "canals" and therefore that the planet was inhabited by intelligent beings. His successors later discovered Pluto.
Marius, Simon (a.k.a. Simon Mayr) (1573-1624) German astronomer who gave Jupiter's "Galilean" moons their names. He and Galileo both claimed to have discovered them in 1610 and likely did so independently. Marius was also the first to observe the Andromeda Nebula with a telescope and one of the first to observe sunspots.
Messier, Charles (1730-1817) Comets were the main interest of this French astronomer; he was the first deliberately to search for new comets, starting with the predicted appearance of comet Halley in 1758-1759. Messier discovered more than 15 new comets, earning him the nickname of he "comet ferret." He also compiled a list of 103 nebulas, star clusters, and galaxies so that he would not mistake them for comets. This list is still used: Andromeda Galaxy, for example, is Messier 31 or M31.
Ukrainian astronomer; discovered the asteroid 951 Gaspra.
Newton, Isaac (1642-1727) Physicist and astronomer from England that became professor of mathematics at the University of Cambridge at the age of 26. He studied dynamics and found the law of universal gravitation. He set up 3 laws of motion, and all his works were published in Principia Mathematica in 1687. He also invented Newton's reflective telescope in the area of optics. By approving Newton dynamics, he physically approved Kepler's motion of planets. Until early 20th century when theory of relativity and quantum theory rose, Newton's dynamics held great power.
Nicholson, Seth Barnes (1891-1963) American astronomer; discovered Lysithea, Ananke, Carme and Sinope; also did important work on sunspots.
Oberth, Hermann (1894-1989) With Robert Goddard and Konstantin Tsiolkovsky, Oberth was a founding father of astronautics, and his books The Rocket into Interplanetary Space (1923) and The Road to Space Travel (1929) are classics. Oberth experimented on rocket motors in the 1930s and, during World War II, developed the German V-2 rocket. In the late 1950s, he spent some time in the US with his old assistant, Wernher von Braun, developing satellite launchers.
Oort, Jan Hendrik (1900-1992) Dutch astronomer made major contributions to knowledge of the structure and rotation of our galaxy. After studying at Groningen University, Oort moved to Leiden University where he became interested in the structure of our Galaxy. By 1927 he realized that the Sun was not at the center of the Milky Way, and that the paths of nearby stars indicated that the galactic center was 30,000 light-years away, behind the constellation Sagittarius. He found that the Sun orbited the Milky Way every 200 million years and that the Galaxy's mass was 100 billion times that of the Sun. In 1951 he traced the shape of the galactic spiral arms by monitoring the radio waves emitted by the hydrogen between the stars. More or less as a sideline, Oort studied comets as well. The result of this work was a theory, now widely accepted, that the Sun is surrounded by a distant cloud of comets, now called the Oort Cloud, bits of which are occasionally hurled into the solar system as comets.
Öpik, Ernst (1893-1985) This Estonian astronomer spent his early life working at the University of Tartu, but in 1948 moved to Northern Ireland, where he later became director of the Armagh Observatory. In 1932, he predicted that the solar system was surrounded by a cloud of comets - a cloud that is now named after Jan Oort. Öpik's work on the way dust particles burn up as they enter Earth's atmosphere has been applied to the design of devices to protect spacecraft from heat as they reenter the atmosphere.
Payne-Gaposchkin, Cecilia (1900-1979) After attending lectures at Cambridge given by Sir Arthur Eddington, Celcilia Payne decided to become an astronomer. In 1923, she left England for Harvard College Observatory in Massachusetts to work with Harlow Shapely. After showing that the temperature of a star is related to its type or spectral class, she established that main sequence stars are made almost entirely of hydrogen and helium. In 1934 she married Sergei Gaposchkin: Working together, they identified variable stars using photographic observations. She also studied very luminous stars, used today for measuring distances to the farthest galaxies. In 1956 she was awarded the Harvard Chair in Astronomy, becoming the first female professor at Harvard.
Penzias, Arno (1933- ) A refugee from Nazi Germany, Penzias moved to the US as a child. He became a radio engineer, joining Bell Telephone Laboratories in 1961. In 1965, while trying to trace a source of radio interference, Penzias and his colleague Robert Wilson found radio waves that came toward Earth from all directions. The sources had a temperature of -270oC, and was what remained from the hot radiation produced by the Big Bang. In 1978 Penzias and Wilson received the Nobel Prize for Physics for their work.
Perrine, Charles Dillon (1867-1951) Argentine-American Astronomer who discovered Himalia and Elara.
Pickering, William Henry (1858-1938) American astronomer. His photographs of Mars, among the earliest obtained, provided a basis for his opposition to Lowell's observations of supposed canals on Mars. Discovered Phoebe.
Planck, Max Karl Ernst Ludwig (?1858-1947) German Physicist who initiated the study of quantum mechanics when he announced in 1900 his theoretical research into radiation and absorption of a black body.
Poliakov, Valeri (1942- ) Russian doctor and cosmonaut who holds two world records: the most time spent in space and the longest single stay in space. He traveled aboard Soyuz TM-6 to the Mir orbiting space station on August 29, 1988, and stayed for 241 days. He returned to Mir on January 8, 1994, when he stayed for 438 days. He was participating in an unusual medical experiment: Before the mission he had some bone marrow removed so that it could be compared with another sample of bone marrow taken when he returned after months of weightlessness.
Ptolemy (a.k.a Ptolemaeus, Claudius) (about 90-168) Alexandrian astronomer, mathematician, and geographer who based his astronomy on the belief that all heavenly bodies revolve around the Earth. The astronomical works of Ptolemy dominated scientific thought until the 17th century. His writing built on the works of Hipparchus and others. To these he added his own observations, made from a rooftop observatory. Ptolemy thought that Earth was a perfect sphere at the center of the universe, surrounded by seven transparent spheres, each of which carried a moving object. In order of speed across the sky (and supposed distance from Earth), these were Moon, Mercury, Venus, Sun, Mars, Jupiter, and Saturn. An eighth sphere contained the stars. He devised a mathematical system that could predict the movement of the planets. He also noted the latitude and longitude of many places on Earth; his maps were so good that Christopher Columbus used them.
Rees, Martin (1942- ) The major work of England's 15th Astronomer Royal has been done at the University of Cambridge where he has concentrated on the study of the centers of active galaxies and the way in which jets of gas from these galaxies interact with the surrounding interstellar medium. He has also written extensively on cosmology and the dark matter in the universe. Rees enthusiastically promotes the communication of science to the general public.
Russell, Henry (1877-1957) An american who became professor of astronomy at Princeton in 1905, Russell studied multiple stars and the relationship between their orbits and masses. From his work on stellar distances, he was able to show that there was a main sequence of stars by plotting stellar luminosity against surface temperature on a graph. This became known as the Hertzsprung-Russell diagram because Ejnar Hertzsprung had plotted a similar graph in 1906. Russell incorrectly predicted that stars evolved by moving either up or down this sequence. In 1929 he suggested, correctly that stars consist mainly of hydrogen.
Ryle, Martin (1918-1984) The son of a physician, Ryle worked on radar during World War II. Afterward, he moved to Cambridge University where he perfected a technique of combining signals from different movable radio telescopes to create one high-resolution image of the onject emitting radio waves. In the late 1940s, Ryle observed the Sun and mapped the regions that gave out radio waves. In the early 1950s he discovered that radio waves were being emitted by distant galaxies. In a series of detailed catalogs of radio sources, he showed that galaxies were closer together in the early universe - strong evidence for the Big Bang. In 1974, Ryle and Antony Hewish were awarded the Nobel Prize for Physics.
Sagan, Carl (1934-1996) American astronomer whose studies concentrated on the atmosphere of planets. In the 1960s he calculated that the surface of Venus was very hot as a result of a runaway greenhouse effect. He also researched the early atmosphere of Earth and experimented with ways in which life could be generated. Sagan was a well-known science popularizer, and in 1980 his television series, Cosmos, was viewed by millions of people around the world.
Sandage, Allan (1926- ) American astronomer who worked at the Mount Wilson and Palomar Observatory in California, starting as an assistant of Edwin Hubble. In1960, with Canadian astronomer Tom Matthews Sandage was the first to provide an optical identification of a quasar. In 1965, he discovered the first "radio-quiet" quasars. In fact, only 1 in 200 quasars emits radio waves. Sandage's measurements of the distances of galaxies indicate that the universe is expanding rather slowly.
Schiaparelli, Giovanni Virginio (1835-1910) Italian astronomer who in 1877 first observed the "canals" on Mars. He believed that the features he observed included straight lines that joined in a complicated pattern. He called these lines 'canali', which means 'channels'. However, the Italian word was mistranslated into the English word 'canals'. That, combined with the suspicious straightness of the lines, bespoke of artificial structures, and this created a furor. Speculations concerning the possibility of intelligent life on Mars sprang up in the popular press. Even astronomers felt the pull of that dramatic possibility. Foremost among these was Percival Lowell, who carried matters far beyond Schiaparelli. He worked at Brera Observatory in Milan and in 1862 realized that the Perseid meteor shower was produced by decay of comet Swift-Tuttle, and that they both had the same orbit. He also incorrectly suggested that one face of Mercury was always pointing toward the Sun.
Schmidt, Bernhard (1879-1935) Born in Estonia, Schmidt moved to Germany to 1900 to study engineering. He then made astronomical lenses and mirrors, eventually joining the staff of the Hamburg Observatory in 1926. Large reflecting telescopes can cover only a very small field of view, and Schmidt devised a telescope for the observatory that used a spherical mirror behind a thin correcting lens to produce a very sharp image over a large field of view. Many Schmidt telescopes have been used for mapping the sky.
Shapley, Harlow (1885-1972) Starting work as a journalist, this American quickly turned to astronomy. While working at Mount Wilson Observatory in California, he used Cepheid variable stars to estimate the distance to globular star clusters. He used these cluster to plot the shape and size of the Milky Way Galaxy. Shapley moved to Harvard in 921 and became famous for the debate he had with Heber Curtis (1872-1942), the director of the Allegheny Observatory in Pittsburgh, about whether the universe consisted of one galaxy or a multitude. Shapely showed that galaxies are clustered into groups.
Shepard, Alan (1923-1998) This US Navy test pilot was the first American in space. His suborbital hop on May5, 1961, took him and his Mercury space capsule to a height of 180km before it landed in the Atlantic Ocean 485km downrange from the launchpad at Cap Canaveral in Florida. He returned to space in early 1971, when he commanded the Apollo 14 Moon mission.
Shklovskii, Josef (1916-1985) Ukrainian astronomer who, in 1953, stared the radio astronomy division of Russia's Astronomical Institute. He was among the first to suggest that spiraling electrons trapped in astronomical magnetic fields produced radio waves with a long wavelength called synchrotron radiation.
Tarter, Jill (1944- ) Turning her back on the hunt for brown dwarf stars, this American astrophysicist became the first radio astronomer to start searching full-time for extraterrestrial intelligence in the early 1970s. As the chief scientist of Project Phoenix, she uses a multi-channel analyzer that takes the signal from large radio telescopes and then listens to many frequencies at the same time, searching for messages.
Tereshkova, Valentina (1937- ) A former textile worker and ameteur parachutist, this Russian cosmonaut was the first woman in space. In June 1963, she made 48 orbits of Earth on the Vostok 6 spacecraft in a 71-hour flight. Nineteen years passed before the next woman flew. Tereshkova married in 1963 and, after having a child, continued to train as a cosmonaut until 1969.
Thomson, William (a.k.a. Lord Kelvin) (1824-1907) British physicist who developed the Kelvin scale of temperature. Also supervised the laying of a trans-Atlantic cable.
Tombaugh, Clyde (1906-1997) American astronomer born in Illionois, this astronomer was too poor to attend college. Instead he joined the Lowell Observatory, in Flagstaff, Arizona, in 1929 as an assistant. Percival Lowell had in 1905 predicted the position of Planet X. To assist the search, Tombaugh built a machine that looked at two photographic plates taken of the same area of sky, a few hours apart, to see if anything had moved against the fixed background of stars. On February 18, 1930, he found Pluto. Uncertain as to whether Pluto was big enough to disturb the orbit of Uranus, he continued his search for another planet for eight years without success.
Tsiolkovsky, Konstantin (1857-1935) Tsiolkovsky produced theories of rocketry but had no resources to build a rocket. By 1898 he had produced a theory that showed how much fuel a rocket would use and how its velocity was related to the thrust of its engines. His book Exploration of Cosmis Space by Means of Reaction Devices (1903) contained designs of liquid hydrogen and liquid oxygen rockets very similar to those in use today. He also showed that multistage rockets would be needed to leave Earth's gravitational field; these, he said, could be stacked one on top of another (as in the US Saturn V) or arranged side by side (as in the Russian space boosters).
American physicist who discovered the Earth's radiation belts (that now bear his name) with an instrument aboard the first successful American satellite, Explorer 1.
Von Braun, Wernher (1912-1977) Von Braun's work on rocket engines in the 1930s led to his appointment as technical director of the rocket establishment in Peenemünde, where he developed the V-2, a liquid-fueled rocket weapon, during World War II. Between 1942 and 1945, more than 5,000 v-2s were built. After the war, the US Army selected von Braun for work in New Mexico. There he designed the Redstone rocket, which in 1958 put Explorer 1, America's first satellite, into orbit, and in 1961 launched Alan Shepard on the first Mercury suborbital mission. In 1960 von Braun was put in charge of the Marshall Space Flight Center in Alabama, where he developed the Saturn rockets that were used to send astronauts to the Moon in the Apollo program.
Whipple, Fred (1906- ) American astronomer who studied in California before moving to Harvard University in Massachusetts in 1931. Whipple became professor of astronomy at Harvard in 1950 and director of the Smithsonian Astrophysical Observatory in 1955. In addition to discovering six new comets, he suggested in 1951 that the heart of a comet was a large ball of snow and dust, the surface of which evaporated as it was heated in the inner solar system. Whipple also studied the orbits of meteors and spacecraft, and figured out how the density and temperature of Earth's upper atmosphere affected their orbits.
Wilson, Robert (1936- ) Born in Houston, Texas, this American physicist joined Bell Telecommunication Laboratories in New Jersey in 1963. Working with Arno Penzias on reducing radio noise in a horn-shaped radio antenna, in 1965 he discovered radio waves coming in all directions from a source that had a temperature of -270oC. This was what remained of the hot radiation produced by the Big Bang. Penzias and Wilson received the 1978 Nobel Prize for Physics for their work.
Young, John (1930- ) American astronaut who trained as a test pilot in the navy. In 1965, he flew in Gemini 3, the first US two-man space mission. After flying in Gemini 10, in 1969 he made 31 lunar orbits in Apollo 10, the dress rehearsal for the first Moon landing. He was commander of the Apollo16 mission in 1972, making three walks on the Moon. In April 1981 he was commander of the first space shuttle flight.
Zwicky, Fritz (1898-1974) Swiss astrophysicist who in 1927 moved to the California Institute of Technology. In 1934, he realized that supernova explosions were much more energetic than novas. He suggested that the supernova explosion destroyed most of the star, leaving only the central core, which appeared as a neutron star. He searched for supernovas but calculated that in any galaxy only one would appear every 400 years. Zwicky also studied clusters of galaxies and observed that, unlike the universe as a while, the clusters were not expanding. |