Posts Tagged ‘ΜΟΟΝ

Mapping the Moon’s Shackleton Crater

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If humans are ever to inhabit the moon, the lunar poles may well be the location of choice: Because of the small tilt of the lunar spin axis, the poles contain regions of near-permanent sunlight, needed for power, and regions of near-permanent darkness containing ice — both of which would be essential resources for any lunar colony.

The area around the moon’s Shackleton crater could be a prime site. Scientists have long thought that the crater — whose interior is a permanently sunless abyss — may contain reservoirs of frozen water. But inconsistent observations over the decades have cast doubt on whether ice might indeed exist in the shadowy depths of the crater, which sits at the moon’s south pole.

Now scientists from MIT, Brown University, NASA’s Goddard Space Flight Center and other institutions have mapped Shackleton crater with unprecedented detail, finding possible evidence for small amounts of ice on the crater’s floor. Using a laser altimeter on the Lunar Reconnaissance Orbiter (LRO) spacecraft, the team essentially illuminated the crater’s interior with laser light, measuring its albedo, or natural reflectance. The scientists found that the crater’s floor is in fact brighter than that of other nearby craters — an observation consistent with the presence of ice, which the team calculates may make up 22 percent of the material within a micron-thick layer on the crater’s floor.

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Written by physicsgg

June 20, 2012 at 7:52 pm


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Trojan collision may have shaped the Moon

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Simulation of a collision between the Moon and a smaller companion moon. (Courtesy: Martin Jutzi and Erik Asphaug)

Differences between the near and far sides of the Moon could be the result of a collision between the Moon and a “Trojan” companion that occurred billions of years ago. That is the conclusion of geophysicists in the US and Switzerland who have done computer simulations on how the Moon would be affected by such a massive impact.

Ever since the Luna 3 space mission ventured behind the Moon in 1959, we have known that the nearside and farside of the Moon are different. The nearside (which always faces the Earth) is dominated by relatively smooth basalt plains called “maria”, while the farside is mountainous and deeply pitted with craters. The two sides are also believed to be different beneath the surface, with the nearside crust appearing much thinner than the crust on the farside.

Scientists have several theories for why the two sides are so different. These include tidal heating of the Moon by the Earth’s gravitational field or a piling up of debris from the huge impact crater at the Moon’s south pole.

Now, Martin Jutzi and Erik Asphaug of the University of California, Santa Cruz have done computer simulations that suggest that the lunar farside is the remnant of a collision between the Moon and a smaller companion moon.

Low-speed crash

According to the pair, the companion moon could have been formed at the same time as the Moon – when a Mars-sized planet collided with the Earth shortly after the solar system was formed…. Read the rest of this entry »

Written by physicsgg

August 4, 2011 at 2:54 pm


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