When Edward Emerson Barnard peered through the 36-inch refractor at Lick Observatory on Sept. 9, 1892, and spotted Amalthea, it marked the first discovery of a moon of Jupiter in 280 years. Galileo had discovered the four largest jovian moons – Io, Europa, Ganymede, and Callisto – in 1610. Though this fifth moon was closerContinue reading "Sept. 9, 1892: Edward Emerson Barnard sees Amalthea"

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On Sept. 8, 2016, the Origins, Spectral Interpretation, Resource Identification, and Security – Regolith Explorer (OSIRIS-REx) mission launched from Cape Canaveral, setting off on its 4.4-billion-mile (2 billion kilometers) journey to asteroid Bennu. About the size of an SUV, the OSIRIS-REx spacecraft carries several cameras, an altimeter used to create maps of Bennu, and anContinue reading "Sept. 8, 2016: OSIRIS-REx launches"

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James Van Allen, who was born in Iowa on Sept. 7, 1914, showed talent and interest in science and math from an early age. A major in physics from Wesleyan College in 1935 was followed by a Ph.D. in nuclear physics in 1939. Before and after World War II – during which he developed antiaircraftContinue reading "Sept. 7, 1914: The birth of James Van Allen"

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The fall of 1618 was a standout when it came to notable comets, boasting three visible to the naked eye. In late August, C/1618 Q1 appeared, first spotted in the skies over Hungary. Johannes Kepler observed the comet throughout the month of September, spotting it from Linz, Austria, through a small telescope on Sept. 6.Continue reading "Sept. 6, 1618: The first comet seen through a telescope"

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