Owen Gingerich

FOCAL POINTA Bright Future for Planetary Astronomy?A CENTURY AGO planetary astronomy was a major component of the work at most major observatories. Unfortunately, in the view of some astronomers and historians, the long "canals of Mars" controversy soured professional opinion of planetary astronomy...

Newton, Halley, and the CometOwen Gingerich, Harvard-Smithsonian Center for AstrophysicsIN 1696 Britain faced a coinage crisis.For years the irregular edges of hand-struck coins had been systematically clipped by thieves, who made a precarious living by selling the tiny silver chips. Finally, the...

Sir Dames South and the Cauchoix ObjectiveNicholas Der Bagdasarian, West Hartford, ConnecticutAS ASTRONOMERS from PalomarL Mountain to Stellafane know, the obsession to construct bigger and better telescopes has been a central theme in the recent history of astronomy. In the early 19th century, an...

Solar Flares and Shock WavesAlan Maxwell, Harvard-Smithsotiian Center for AstrophysicsFlares on the sun are among the most dramatic events in the solar system. a flare appears with hardly any warning as a small, bright patch on the solar surface and sends material exploding out\vard through the...

gle of the narrowest sector are also cited. The dates are based on Ephemeris time, which differs by less than three hours from Universal time during the period considered. Before 1583 the Julian calendar has been used. Values in the fourth and sixth columns have been rounded to the nearest integer....