• Mona Evans

    Johann Gottfried Galle (1812-1910). Based on the calculations of Urbain Le Verrier, Galle and his assistant Heinrich Louis d'Arrest at the Berlin Observatory found the planet Neptune. The orbit of Uranus wasn't quite fitting the expected one and Le Verrier thought it was because the gravity of an unknown planet was affecting it. (Portrait: Olga Radomsky) ©Mona Evans, "Neptune Facts for Kids" http://www.bellaonline.com/articles/art33048.asp

  • Natalia Carnevale

    German observatory astronomer Johann Gottfried Galle discovered the planet Neptune. He was assisted by Urbain Jean Joseph Le Verrier, a French mathematician who specialized in celestial mechanics. Neptune was named by Le Verrier after the Roman mythological god of the sea.

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Christian Mayer (1719-1783), Czech astronomer and teacher. (There is no known portrait of Mayer.) By invitation, Mayer observed the 1769 transit of Venus in St Petersburg. He was Court Astronomer at Mannheim (Germany) until the Jesuit order, of which he was one, was dissolved by the Pope. He was still able to continue his astronomical studies. His is known today for his study of double stars, of which he proposed some were true binaries orbiting each other.

Joint medal for Pierre Janssen and Norman Lockyer issued by the French Académie des Sciences. It was in recognition of their independent innovation of a method of studying the Sun when it was not eclipsed.

John Couch Adams (1819-18920 (Portrait: Hubert von Herkomer, c. 1888) Adams was an English astronomer and mathematician. Inspired by Mary Somerville, he calculated an orbit for an unknown planet disturbing the orbit of Uranus. Astronomers didn't find it, despite Adams's good calculations. But Johann Galle found it using LeVerrier's calculations.

São Tomé and Príncipe issued a set of stamps to mark the 90th anniversary of Arthur Eddington's eclipse expedition to the island. The results supported Einstein's General Theory of Relativity. (Credit: Ian Ridpath) Mona Evans, "Einstein's Eclipse" www.bellaonline.c...

Gene Shoemaker (1928-1997) donning a Bell rocket belt while training astronauts. Shoemaker was a geologist with a particular interest in asteroids and meteors and their craters, and one of the pioneers of planetary science. A possible candidate for an Apollo mission, he was ruled out on health grounds. Along with astronomer wife Carolyn and their friend David Levy, he was co-discoverer of a comet that crashed into Jupiter. After his death Lunar Prospector took some of his ashes to the Moon.

Jan Hendrik Oort (1900-1992) was a Dutch astronomer who made significant contributions to the understanding of the Milky Way and who was a pioneer in the field of radio astronomy. The Oort Cloud is named for him, as he theorized the existence of this distant reservoir of long period comets.

Astronomers Priscilla Fairfield Bok (1896-1975) & Bart Bok (1906-1983) at Mount Stromlo Observatory, Australia. Mona Evans, "B is for Bok Globule", www.bellaonline.c...

Mary Somerville (1780-1872) was the foremost woman of science of her age, by both contemporary and modern standards. An astronomer, mathematician, and geographer, she was at the forefront of the transmission of new scientific and mathematical ideas and practices to the literate public of nineteenth century Great Britain through her books and scientific writings. Mona Evans, "Mary Somerville and the World of Science - book review" www.bellaonline.c...

Vesto Melvin Slipher (1875 – 1969). Slipher, of the Lowell Observatory in Arizona, was the first to measure the radial velocities of what we now know are galaxies. He saw that M31 was blueshifted, and stated that it meant it was moving towards us. However he found that most of them were redshifted. This was the first evidence of what was later understood as the expansion of the Universe.

Clyde Tombaugh using his blink comparator. It "blinks" back and forth between two photos taken at different times. Anything that has moved during that time can be spotted. This is how he found Pluto on February 18, 1930. (Credit: Science Photo Library) Mona Evans, "Pluto Is a Dwarf Planet" www.bellaonline.c...

Day of Remembrance - Challenger memorial, Arlington National Cemetery.

Carl McNair tells the story of his brother Ronald, an African American kid in the 1950s who set his sights on the stars. Ronald McNair, PhD in physics from MIT and accomplished musician, also became a NASA astronaut. He died when the shuttle Challenger broke up soon after launch on January 28, 1986.

Joseph Jérôme Lefrançois de Lalande (11 July 1732 – 4 April 1807) was a French astronomer, lecturer and writer. His name is one of the 72 names inscribed on the Eiffel Tower.

Colin Pillinger (1943 - 2014) with the Beagle 2 landing craft in 2002. The space scientist was the driving power behind the Beagle 2 mission. The craft landed on Mars on Christmas Day 2003. It was never heard from again. Sadly, Pillinger never learned of Beagle's fate. It wasn't finally located until January 2015, using images from the HiRise camera on NASA's Mars Reconnaisance Orbiter.

Subrahmanyan Chandrasekhar (1910 - 1995) Indian physicist and mathematician. He made major contributions to understanding of stellar evolution. A Nobel Prize winner in physics, the Chandra space telescope is named for him. Mona Evans, "Empire of the Stars - book review" www.bellaonline.c...

Johannes Kepler was born on 27 December 1571 in Weil der Stadt, near Stuttgart in Germany. He was a mathematician, astronomer & astrologer. He's best known for his laws of planetary motion, which also provided one of the foundations for Isaac Newton's theory of universal gravitation (he is also known as an assistant to astronomer Tycho Brahe). Mona Evans, "Johannes Kepler - His Life" www.bellaonline.c...

Albert Einstein said: "Knowledge is limited. Imagination encircles the world." (Image: Famous Hubble Space Telescope image of stellar nursery)

William Lassell (1799-1880). Prominent English astronomer who discovered Neptune's moon Triton, a moon of Saturn and two moons of Uranus. He served as president of the Royal Astronomical Society and was awarded its Gold Medal. He was also elected a Fellow of the Royal Society in and won their Royal Medal in 1858.

Francis Baily (1774-1844) was an English astronomer best known for his observations of "Bailey's beads" during a solar eclipse. He twice won the Gold Medal of the Royal Astronomical Society and was four times elected president of the society. Many decades after Lacaille's death, Bailey processed Lacaille's observational data so that a catalog could finally be published. Mona Evans, "Nicolas-Louis de Lacaille" www.bellaonline.c...

TIME Magazine Cover: Sir Arthur Eddington - Apr. 16, 1934. Eddington (1882-1944) was a prominent English astrophysicist, mathematician, professor, and popular science communicator. His eclipse expedition that confirmed a prediction of Einstein's theory of general relativity made both Einstein and Eddington celebrities. Mona Evans, "Einstein's Eclipse" www.bellaonline.c...

"Stuff of Genius: John Herschel: Blueprints" (HowStuffWorks) This video, which needs a Flash player to run, explains how John Herschel invented the photographic process which became known as blueprints. It also tells you why they were important. Mona Evans, "John Herschel" www.bellaonline.c...

Friedrich Wilhelm Bessel (1784-1846). (Portrait by Christian Albrecht Jensen) Prussian astronomer and mathematician, director of the Königsberg Observatory, and the first person to be credited with measuring the distance to a star using parallax.

Heinrich Wilhelm Matthias Olbers (1758-1840). German physician and astronomer. Best known for his discovery of the two asteroids Pallas and Vesta.

Urbain Le Verrier (1811-1877) French mathematician who specialized in celestial mechanics. His calculations on the disturbance to the orbit of Uranus led to the discovery of Neptune. (Portrait by Felix Henri Giacomotti) Mona Evans, "Uranus and Neptune - Twin Planets" www.bellaonline.c...

“A new consciousness is developing which sees the earth as a single organism and recognizes that an organism at war with itself is doomed. We are one planet. One of the great revelations of the age of space exploration is the image of the earth finite and lonely, somehow vulnerable, bearing the entire human species through the oceans of space and time.” — Carl Sagan