Adams, John Couch-- (1819-1892)
English astronomer and mathematician. At the age of 24, he became the first person to predict the position of a planetary mass beyond Uranus. Unfortunately, he didn't publish his prediction, and Johann Gottfried Galle used Urbain Jean Joseph LeVerrier's calculations to discover Neptune.

Arago, Dominique Francois Jean--(1786-1853)
French astronomer and physicist and Director of the Paris Observatory. He is credited for discovering that rotation may produce magnetism.

d'Arrest, Heinrich Louis--
Danish astronomer. He assisted Johann Gottfried Galle with discovering Neptune. Armed with Urbain Jean Joseph LeVerrier's prediction, Galle and d'Arrest began the search. With Galle looking into vast space and d'Arrest checking the sky chart, they checked each star on the chart. After just a few minuets, d'Arrest cried, "That star is not on the map!!". By saying this, he earned his place in history.

Barnard, Edward Emerson--(1857-1923)
American astronomer. He discovered Jupiter's satellite Amalthea and Barnard's star, the second closest star system to the sun.

Bond, William Cranch--(1789-1859)
One of the earliest American astronomers. He rose from poverty and overcame a lack of formal education. He became the first director of the Harvard College Observatory. There he studied Saturn and with William Lassell, discovered its moon Hyperion.

Brahe, Tycho--(1546-1601)
Danish astronomer. His accurate astronomical observations formed the basis for Johannes Kepler's laws of planetary motion.

Cassini, Giovanni Domenico--(1625-1712)
Italian-born French astronomer. He was also know as Jean Dominique and was the first director of the Royal Observatory in Paris. He discovered four of Saturn's moons (Dione, Rhea, Lapetus, and Tethys) and the major gap in its rings.

Copernicus, Nicolaus--(1473-1543)
Polish astronomer. He advanced the heliocentric theory, the theory that the Earth and other planets revolve around the sun. This theory was highly controversial. (The heliocentric idea was first theorized by Aristarcus of Samos in the third century BC, a fact known to Copernicus but long ignored.)

Galilei, Galileo--(1564-1642)Italian astronomer. In 1610's, Galileo claimed to have seen four moons orbiting Jupiter, mountains on the Moon, phases like that of the moon on Venus, and found evidence to prove that the Milky Way was made up of tiny stars.

Galle, Johann Gottfried--(1812-1910)
Italian astronomer and physicist. He was the first to use a telescope to observe the stars, and discovered Jupiter's four largest moons. Galileo was an outspoken supporter of Copernicus's heliocentric theory.

Hale, George Ellery--(1868-1938)
American astronomer. He founded the Yerkes, Palomar, and Mt. Wilson Observatory.

Hall, Asaph--(1829-1907)
American astronomer. He discovered the two moons of Mars, Dimos and Phobes.

Halley, Edmond--(1656-1742)
English astronomer. He applied Newton's laws of motion to historical comet data and correctly predicted the reappearance of the comet which now bears his name.

Herschel, Sir William--(1738-1822)
British astronomer. He discovered Uranus and cataloged over 800 double stars and 2, 500 nebulae.

Hubble, Edwin Powell--(1889-1953)
American astronomer. His observations proved that galaxies are "island universes". His greatest discovery was the linear relationship between a galaxy's distance and speed with which it is moving. The Hubble Space Telescope is named in his honor.

Huygens, Christiaan--(1629-1695)
Dutch physicist and astronomer. He first described the nature of Saturn's rings in 1655 and discovered its moon, Titan.

Kepler, Johannes--(1571-1630)
German astronomer and mathematician. He is considered a founder of modern astronomy and formulated the three laws of planetary motion.

Kuiper, Gerard--(1905-1973)
Dutch-born American astronomer. He is best known for his study of the surface of the moon. He discovered Miranda and Nerid and found atmosphere on Titan.

Lagrange, Joesph Louis--(1736-1813)
French mathematician and astronomer. He made a number of contributions to the study of celestial mechanics.

Lassell, William--(1799-1880)
British astronomer. Lassell discovered Triton, Neptunešs largest satellite and Saturnšs moon ,Hyperion, with William Cranch Bond.

Lowell, Percival--(1855-1916)
American astronomer. He founded the Lowell Observatory in Arizona in 1894, where his studies of Mars led him to believe that the markings on the surface were "canals", and therefore that the planet was inhabited by intelligent beings. His successors later discovered < A HREF="PLUTO.HTML">Pluto.

Marius, Simon--(1573-1624)
German astronomer. He gave Jupiteršs "Galilean" moons their names. He and Galileo both claimed to have discovered them in 1610 and probably did so seperatley. They soon became incolved over a dispute over priority. Marius also was the first to observe the Andromeda Nebula with a telescope and was one of the first to observe sunspots.

Neujmin, Grigority--
Ukranian astronomer. He discovered asteroid 951, Gaspra.

Newton, Issac--(1642-1727)
English cleric and scientist. Newton discovered the classical laws of motion and gravity.

Oort, Jan Hendrick--(1900-1992)
Dutch astronomer. He made important discoveries regarding the structure and rotation of our galaxy. He also studied comets and came up with a theory that the sun is surrounded by a distant cloud of comet-like material, now know as the Oort cloud.

Pickering, William Henry--(1858-1938)
American astronomer. He produced the first photographs of Mars that helped to overturn Lowell's theory about canals on Mars. He also discovered Phobe, one of the moons on Mars.

Ptolemy, Claudius--(87-150)
Alexandrian astronomer, geographer, and mathematician. He based his study of astronomy on the fact that Earth was at the center of the universe.

Schiaparelli, Giovanni Virginio--(1835-1910)
Italian astronomer. In 1877 he was the first to observe "canals" on Mars. He called these lines 'canali' which means 'channels'. However it was mistranslated into the English word, 'canals'.

Thomson, William--(1824-1907)
British physicist. He developed the Kelvin scale of temperature.

Tombaugh, Clyde--(1906-1997)
American astronomer. He discovered Pluto in 1930 at the Lowell Observatory.

Van Allen, James A.--
American physicist. He discovered Earth's radiation belts, which are know named after him.

HOME