In celebration of 1,000 days in orbit, the Lunar Reconnaissance Orbiter team released two beautiful videos of our moon, one a fiery drama showing the moon's tough evolution and another touring its most interesting sites.
When our planet was still forming, collisions with other planetesimals — and a Mars-sized object that sheared away the moon — turned the embryonic Earth into a roiling ball of molten rock. Iron and other heavy elements sank toward the core, and other iron-loving elements did, too. As a result, there’s plenty of gold at our planet’s center. So why, then, is there also gold in the hills? A new study supports the theory that it was all a gift from above.
U.S. coasts seemed as vulnerable 62 years ago as they suddenly seemed after September 11. Today the threat is understood to be hidden-bombs or terrorists arriving in container ships-but then fear centered around a naval assault. Batteries of 16- and 12-inch guns were built near principal harbors, but mostly went unused. Where they might have been tested, at Pearl Harbor, they were silent, ineffective against the surprise aerial attack.
(Left: The concept
of umbrella coastal defense— placing large weaponry near presumed major entry points—took a beating