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Seated Liberty dollar obverse, 1860

The Seated Liberty dollar was a dollar coin designed by Mint Chief Engraver Christian Gobrecht and struck by the United States Mint from 1840 to 1873. The coin's reverse features a heraldic eagle first seen on coins in 1807, based on a design by late Mint Chief Engraver John Reich; the coin's obverse is based on the Gobrecht dollar. "In God We Trust" was added to the dollar in 1866 following its introduction to other US coins earlier in the decade. In the final years of the series, there was more silver produced in the US, and mintages increased. These were the last dollar coins before the Coinage Act of 1873 temporarily ended their production for American commerce and authorized the trade dollar for use in foreign commerce. Representatives of silver interests were unhappy when the metal's price dropped again in the mid-1870s; they advocated the resumption of the free coinage of silver into legal tender. After passage of the Bland-Allison Act in 1878, silver dollar production resumed with the Morgan dollar. (Full article...)

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April 21

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Atmosphere of Jupiter

A 14-frame clip showing the atmosphere of Jupiter as viewed from the NASA probe Cassini. Taken over a span of 24 Jupiter rotations between October 31 and November 9, 2000, this clip shows various patterns of motion across the planet. The Great Red Spot rotates counterclockwise, and the uneven distribution of its high haze is obvious. To the east (right) of the Red Spot, oval storms, like ball bearings, roll over and pass each other. East-west bands adjacent to each other move at different rates. Strings of small storms rotate around northern-hemisphere ovals. The large grayish-blue "hot spots" at the northern edge of the white Equatorial Zone change over time as they proceed eastward across the planet. Ovals in the north rotate counter to those in the south. Small, very bright features appear quickly and randomly in turbulent regions, possibly lightning storms. The smallest visible features at the equator are about 600 km (370 miles) across.

Animation: NASA/JPL/University of Arizona

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