Lowells Calculations And My Search

It has been stated by some writers of the Pluto story that Percival Lowell's calculations greatly aided my finding Pluto. Quite to the contrary, when I found out in the latter part of 1929 how Lowell had drastically changed his predicted position of Planet X from Libra to Gemini, this indicated to me that considerable uncertainty was involved, and I could not take the prediction seriously. At the start of my trans-Neptunian planet survey at the Lowell Observatory in the spring of 1929, I...

William H Pickering And Planets O P Q R S T And U

Pickering (1858-1938) made and published more predictions for the existence of trans-Neptunian planets than any other astronomer. Like Percival Lowell, Pickering was born in Boston, came from a family of social and intellectual distinction, was well educated (M.I.T.), and had travel and adventure in his blood (Pickering especially liked primitive areas and mountain climbing). Like Lowell, Pickering was a bundle of energy. Besides leading four solar eclipse expeditions as a staff...

Galileos Observation Of Neptune And Its Implications

Jr., Jet Propulsion Laboratory Nearly two and a half centuries before the discovery of Neptune in 1846, the astronomer Galileo unknowingly observed that planet through his telescope, noted its motion in the sky, and drew a diagram of its location. This startling fact was uncovered in 1980 by Charles T. Kowal and Stillman Drake while searching through Galileo's notebooks. Galileo drew the object as a background star for reference. There is no question, however, that it...

Epilogue For Voyager

Voyaier2's planetary mission is complete. It is now embarked on its interstellar mission and a journey through the ages. On its Grand Tour of the giant planets, Voyager 2 visited 60 worlds 25 of them for the first time, 16 of them previously unknown. The cost of the Voyager project (both Voyager 1 and Voyager 2) was 865 million, or 3.60 for every American citizen the price of one lunch at McDonald's* Never again within our solar family can there be a mission like Voyager 2 first to explore four...

George Biddell Airy Astronomer Royal

Young George was not popular with his classmates at school because, he said, he had very little animal vitality. He was also snobbish and conceited. But his classmates endured him when he created useful gadgets for mischief such as peashooters. At the age of 12, George, already concerned for his own advancement, conspired with his mother's brother, a wealthy and well-educated farmer, to adopt and hide him from his family without informing them so that he would have better social contacts. His...

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such an extraordinarily beautiful planet, said astronomer Richard S., of the giant worlds, Neptune, surprisingly, has more visible a res in its atmosphere than Uranus or even Saturn. Only Jupiter, of J e four planets along Voyager2's route, could exceed Neptune in cloud- Yet how strange to see convection clouds and even eruptive cloud vior on a world so far from the Sun. The Sun's heat drives the weather on Earth. But Neptune is too distant for sunlight to stir its at mosphere significantly....

Voyager

NASA's Pioneer 10 and 11 and Voyager 1 and 2 spacecraft are headed out of the solar system. Artist Don Davis portrays Pioneer lO, at present the most distant craft, moving outward from the Sun (the brightest star visible) and away from the heart of our Milky Way galaxy. heliopause to contract. Solar scientists think that the heliopause lies at a distance of 100 to 200 astronomical units 100 to 200 times the Earth's distance from the Sun. Neptune orbits at a distance of 30 astronomical units....

Toward Uranus

Fate often smiles kindly upon great endeavors. Charles Kohlhase. Voyager mission Design Manager A flashlight provides more light in one second than Uranus has provided to Earth in the 200 years since it was discovered by Herschel in 1781.' No wonder that two centuries passed before Uranus was revealed in detail. Watching Uranus as scarcely more than a dot in the skies had told astronomers about its orbit. Watching its moons in orbit had told astronomers the mass of Uranus and that the planet...

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The work that led directly to the Grand Tour began at the Jet Propulsion Laboratory in 1965 when 1 was given a summer position to supplement my Ph D stipend as a graduate student in aeronautics at the California Institute of Technology. I had worked at JPL several times previously doing engineering work on missile trajectories, aerodynamics, and guidance systems. I learned as much from working there as from any of my formal graduate studies. The outstanding engineers at JPL had been a major...

Jupiter

The internal structure of Uranus compared to that of Earth and Jupiter. Voyager 2 indicated that a two-layer model for the interior of Uranus is correct rather than the earlier three-layer model. (The internal structure of each planet is drawn to scale, but not its size compared to the others. Uranus is about 4 times the diameter of Earth Jupiter is more than 11.) the sunlight it receives. The upper atmosphere of Uranus, warmed feebly by sunlight and the weak internal heat of the planet, is...

Planets Beyond

Astronomers carefully measured the amount of light coming fro** Pluto-Charon system. The two are brightest when they are sideT to the line of sight neither blocking the light of nor casting a on the other. When Charon is in transit across the face of Pluto the bined light of the planet-moon system declines by about 40 percent I 0.55 magnitude) as Charon blocks part of the reflective surface of Pi from view. As Charon emerges from transit, the brightness of Pi Charon is again at a maximum. Then...

Mekschels Telescopes

The discovery of Uranus brought Herschel a flood of inquiries about his instruments and techniques. Only then did it begin to dawn on him that he, William Herschel, an amateur isolated in Bath, England, was the best-equipped astronomer in the world. Despite Herschel's sale of telescopes, the world did not catch up with him in his lifetime. Because other astronomers did not check his observations on stars and faint nebulae, they could not appreciate his work on the structure of the heavens....

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Callisto, the outermost large moon of Jupiter. Voyager pieces showed that it was saturated with craters. Any new craters formed by gashing asteroids or comets will obliterate older craters. This thoroughly Watered landscape suggests that Callisto has changed little since it formed. .VASAjef Propulsion Laboratory 0g(e2 and 29. Titan, Saturn's largest satellite and the second-largest moon in the solar system. Only two moons, Titan and Neptune's TViton, have permanent atmospheres. The...

Song Of The Heavens Caroline Herschel 17501848

I never forgot, wrote Caroline Herschel, the caution my dear Father gave me against all thought of marrying, saying as I was neither handsome nor rich it was not likely that anyone would make me an offer, till perhaps, when advanced in life, some old man might take me for my good qualities.1 So Caroline dreamed of a career to keep her from being dependent on family members. She had a good singing voice. She came from a musical family. But her mother disapproved of careers for women. Anna even...

The Discovery of Uranus

It was that night its turn to be discovered. William Herschel describing his discovery of Uranus , very different from any comet I ever read any description of or saw. Nevll Maskelyne, Astronomer Royal. April 1781 On March 13, 1781, amateur astronomer William Herschel discovered a new planet. It was completely unexpected. For as long as anyone could remember, for the thousands of years of recorded history, the solar system ended at Saturn. Mercury, Venus, Mars, Jupiter, Saturn, the Sun. and the...

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Each exposure captured 50,000 stars. Then pushed on into Gemini, closer to the Milky Way. Now each plate p vided 400,000 stars to be inspected. Five days into his search, on April 11, 1929, Tombaugh exposed pl number 10 and captured the object he was seeking. He captured itagsjj on April 30, its companion plate for comparison. But the ninth pW went unnoticed by the Lowell Observatory astronomers who weI responsible for the blink comparator examination. Plate 10 had cracked in the...