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Saturday, April 24, 2010

Top 10 Things You Didn't Know About the Moon

Searching for the Lunar Jackpot — Ice


 It may not sound like precision science, but researchers are hopeful that plowing a spacecraft into the moon's surface may reveal a hidden layer of frozen water beneath the surface. On Oct. 9, a NASA satellite will hurl a spent rocket into a dark and frigid lunar crater at 5,600 m.p.h.; the impact will equal the force of 1.5 tons of TNT and kick up a massive, six-mile-high plume of dirt and debris. The satellite — the Lunar Crater Observation and Sensing Satellite, or LCROSS — will then photograph and study the plume for evidence of water or ice from colliding comets. After a few minutes of observation, the space vehicle will plunge into the moon's surface as well. Images taken by an Indian satellite earlier this year suggested there was indeed water on the moon; confirming the discovery would be a major boon for scientists who dream of humans inhabiting the moon, Mars and other planets someday.

Was it something we said? While our two celestial bodies remain locked in orbit, the moon is slowly — very slowly — inching away from Earth, at a rate of about 3.8 cm a year. Right now the moon is more than 238,000 miles from Earth, but when it formed, it was just 14,000 miles away.
How do scientists know? The moon's distance is measured by bouncing laser beams off reflectors on the moon's surface that astronauts from the Apollo missions left behind. Scientists can measure the time it takes for the laser beams to travel there and back and calculate the distance with a high degree of accuracy. Eventually, the moon's distance will substantially weaken the oceans' tides and total eclipses of the sun won't be possible for observers on Earth, since the moon will have moved too far away. But that could still take another billion years.

 What was the first sport played on the moon? That would be golf. In 1971, Apollo 14 astronaut Alan Shepard swung a makeshift 6-iron on the moon's surface — and missed the ball. His second swing, however, connected, and the golf ball went flying "miles and miles and miles," as Shepard put it after his swing. In reality, the ball traveled only a few hundred yards — not bad for a 6-iron. That's not Shepard's fault; while the moon's gravity is only one-sixth Earth's, his space suit was so stiff that he could swing the club with only one hand.

Lunar Souvenirs

The astronauts of NASA's Apollo missions collected some 840 lb. of lunar rocks and debris during the 340 hours they spent tooling around on the moon. Since they were brought to Earth, however, the samples have ended up in some unusual places. During the Nixon Administration, nearly 270 moon rocks were presented as gifts to foreign nations. But when a fake turned up in the Netherlands' national museum in September, the Associated Press launched an independent investigation to track the whereabouts of the rest — only to find that many had disappeared. "NASA turned over the samples to the State Department to distribute," one NASA historian told the AP. "We don't have any records about when and to whom the rocks were given." Apollo astronauts were allowed to keep a few rocks as lunar souvenirs, under the condition that they would never be sold but instead passed down from generation to generation. Today, NASA's remaining samples are kept in Teflon bags and stored in nitrogen-filled steel cabinets at the Johnson Space Center in Houston. Any researcher who wishes to handle them must wear three pairs of gloves to prevent contamination.

Slow and Steady Wins the (Space) Race

The first creature to orbit the moon was neither man nor monkey, but a pair of Soviet turtles. The tortoises — along with a passenger list of mealworms, wine flies, seeds and bacteria — were part of a biological payload launched by the Soviet Union in September 1968.
After the Zond 5 spacecraft returned to Earth, the animal comrades were retrieved from the Indian Ocean and found not to have a scratch on them; the shells probably helped. They had, however, lost 10% of their weight, although researchers didn't observe a permanent decrease in appetite.

Seas on the Moon?

 The massive lava plains on the lunar service, dubbed seas by Earth-bound observers, were created by the violent impacts of meteors. Interestingly, most of these lava seas are on the side facing Earth; the force of Earth's gravity pulls the moon's molten interior closer to the surface, making it more susceptible to seeping out during a meteor strike.

Easier Than Peace on Earth

The U.S. joined with the Soviet Union in 1967 to create the Outer Space Treaty, declaring the moon subject to a similar set of rules as those used to govern international waters on Earth. The treaty, which 97 other countries are now party to, makes the moon off-limits for military purposes, keeping countries from ever constructing bases or weaponry on the lunar surface.

Weather in Moon

Talk about extreme weather changes. The moon's surface temperature varies by nearly 500°F, from -240°F when it is dark to 220°F in the sun. And once those extreme temps set in, they stick around for a while — a spot on the moon spends about 13 days in frigid darkness, followed by 13 days in water-boiling sunlight. The lack of atmosphere, which on Earth helps trap heat so it doesn't all dissipate at night, accounts for the wild temperature swings. However, if you dig a meter below the moon's surface, the temperature evens out to a nearly constant -31°F.

The moon doesn't have a dark side, although there's always part of it in the dark — just as there's always a part of Earth that's experiencing night. There is a far side of the moon that we can't see from Earth: because of the way the moon orbits, it always keeps the same side facing us. But the far side is light just as often as it is dark.

Everlasting Footprints

No atmosphere on the moon means no wind or weather — and that, luckily, means no erosion of mankind's historic tracks and prints that still dot the lunar surface. To prove it, NASA's Lunar Reconnaissance Orbiter (LRO) sent back photos in July of the still visible tracks from five of the six Apollo landing sites. While on the moon in 1971, Apollo 14 astronauts Edgar Mitchell and Alan Shepard left behind an Apollo Lunar Surface Experiments Package, or ALSEP, along with sampling equipment and a small cart. The LRO photos were able to clearly show the footpath the astronauts had worn between the two artifacts, and future images are expected to have two to three times the resolution. "The images are fantastic, and so is the focus," says LRO principal investigator Mark Robinson. "It's great to see the hardware on the surface, waiting for us to return."

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