The Shrinking [Expanding] Moon

New images from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft show the moon's crust is being stretched, forming minute valleys in a few small areas on the lunar surface. Scientists propose this geologic activity occurred less than 50 million years ago, which is considered recent compared to the moon's age of more than 4.5 billion years.

A team of researchers analyzing high-resolution images obtained by the Lunar Reconnaissance Orbiter Camera (LROC) show small, narrow trenches typically much longer than they are wide. This indicates the lunar crust is being pulled apart at these locations. These linear valleys, known as graben, form when the moon's crust stretches, breaks and drops down along two bounding faults. A handful of these graben systems have been found across the lunar surface.

We think the moon is in a general state of global contraction because of cooling of a still hot interior," said Thomas Watters of the Center for Earth and Planetary Studies at the Smiths...
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Birth of a Great Observatory

See this fascinating story from ESOCast. For many centuries, maps of the southern sky showed extensive blank areas -- the Terra Incognita of the heavens. The year 1595: For the first time, Dutch traders set sail to the East Indies. At night, navigators Pieter Keyser and Frederik de Houtman measured the positions of more than 130 stars in the southern sky. Soon, celestial globes and maps showed twelve new constellations, none of which had ever been seen before by any European.

The British were the first to construct a permanent astronomical outpost in the southern hemisphere. The Royal Observatory at the Cape of Good Hope was founded in 1820. Not much later, John Herschel built his own private observatory, close to South Africa's famous Table Mountain.

What a view! Dark skies. Bright clusters and star clouds high overhead. Little wonder that Harvard, Yale and Leiden observatories followed suit with their own southern stations. But the exploration of the southern sky still too...
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