Moon
hideThe Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is 384,403 km, about thirty times the diameter of the Earth. The common centre of mass of the system (the barycentre) is located about 1,700 km—a quarter the Earth's radius—beneath the surface of the Earth. The Moon makes a complete orbit around the Earth every 27.3 days (the orbital period), and the periodic variations in the geometry of the Earth–Moon–Sun system are responsible for the phases of the moon, which repeat every 29.5 days (the synodic period).
The Moon's diameter is 3,474 km, a little more than a quarter of that of the Earth. Thus, the Moon's surface area is less than a tenth that of the Earth (about a quarter the Earth's land area, approximately as large as Russia, Canada, and the United States combined), and its volume is about 2 percent that of Earth. The pull of gravity at its surface is about 17 percent of that at the Earth's surface.
The Moon is the only celestial body to which humans have traveled and upon which humans have performed a manned landing. While the Soviet Union's Luna program was the first to reach the Moon with unmanned spacecraft, the NASA Apollo program by the United States achieved the only manned missions to date, beginning with the first manned lunar mission by Apollo 8 in 1968, and six manned lunar landings between 1969 and 1972- the first being Apollo 11 in 1969. Human exploration of the Moon temporarily ceased with the conclusion of the Apollo program, although a few robotic landers and orbiters have been sent to the Moon since that time. The U.S. has committed to return to the moon by 2018.
For more information about Moon, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
News tagged with moon
LCROSS Impact Finds Water on the Moon
Space & Earth / Space Exploration
Nov 13, 2009 |
4.9 / 5 (31) |
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(PhysOrg.com) -- The argument that the moon is a dry, desolate place no longer holds water. Secrets the moon has been holding, for perhaps billions of years, are now being revealed to the delight of scientists ...
Scientists explain puzzling lake asymmetry on Titan
Space & Earth / Space Exploration
Nov 29, 2009 |
4.4 / 5 (14) |
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Researchers at the California Institute of Technology (Caltech) suggest that the eccentricity of Saturn's orbit around the sun may be responsible for the unusually uneven distribution of methane and ethane ...
Red Sea coral seen to feed on jellyfish
Nov 17, 2009 |
4.5 / 5 (12) |
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(PhysOrg.com) -- Corals depends on the products of photosynthetic algae for most of their food, but they also eat tiny plankton. Now, for the first time, there is evidence of a coral eating jellyfish.
Rosetta bound for outer Solar System after final Earth swingby (w/ Video)
Space & Earth / Space Exploration
Nov 13, 2009 |
4.9 / 5 (7) |
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(PhysOrg.com) -- This morning, mission controllers confirmed that ESA’s comet chaser Rosetta had swung by Earth at 8:45 CET as planned, skimming past our planet to pick up a gravitational boost for an epic ...
2 parachutes malfunctioned in NASA test flight
Space & Earth / Space Exploration
Oct 30, 2009 |
4.8 / 5 (6) |
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(AP) -- Two of three parachutes malfunctioned in the test flight of a prototype moon rocket earlier this week, causing major damage to the booster, NASA said Friday.
NASA's Ares I-X moon rocket makes first test flight
Space & Earth / Space Exploration
Oct 28, 2009 |
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(PhysOrg.com) -- NASA's Ares I-X test rocket lifted off at 11:30 a.m. EDT Wednesday from NASA's Kennedy Space Center in Florida for a two-minute powered flight.
Robot Armada Might Scale New Worlds
Space & Earth / Space Exploration
Oct 28, 2009 |
4.3 / 5 (11) |
5
(PhysOrg.com) -- An armada of robots may one day fly above the mountain tops of Saturn's moon Titan, cross its vast dunes and sail in its liquid lakes.
Jupiter's Moon Europa Has Enough Oxygen For Life
Space & Earth / Earth Sciences
Oct 16, 2009 |
4.8 / 5 (94) |
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New research suggests that there is plenty of oxygen available in the subsurface ocean of Europa to support oxygen-based metabolic processes for life similar to that on Earth. In fact, there may be enough ...
How the Moon produces its own water
Space & Earth / Space Exploration
Oct 15, 2009 |
4.7 / 5 (15) |
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(PhysOrg.com) -- The Moon is a big sponge that absorbs electrically charged particles given out by the Sun. These particles interact with the oxygen present in some dust grains on the lunar surface, producing ...
Water Bears to Travel to Martian Moon, Test Theory of Transpermia
Space & Earth / Space Exploration
Oct 13, 2009 |
3.9 / 5 (14) |
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(PhysOrg.com) -- Tiny microscopic creatures commonly known as water bears (also called Tardigrades), along with a few other life forms, will be sent to the Martian moon Phobos to test whether organisms can ...
Astronomers Detect Sodium Gas Ejected by Lunar Impact
Space & Earth / Space Exploration
Oct 12, 2009 |
4.4 / 5 (21) |
10
(PhysOrg.com) -- Boston University astronomers announced today observations of a cloud of sodium gas ejected from the Moon’s surface as a result of the NASA impact experiment that was part of its Lunar Reconnaissance ...
Alfalfa sprouts hold the line on meandering streams (w/ Video)
Space & Earth / Earth Sciences
Oct 05, 2009 |
4.3 / 5 (3) |
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(PhysOrg.com) -- Sinuous, meandering streams produce diverse and wildlife-rich habitats and are the aim of many river restoration efforts, but until now, the bank, water flow and sediment conditions required ...
New NASA temperature maps provide 'whole new way of seeing the moon'
Space & Earth / Space Exploration
Sep 17, 2009 |
4.9 / 5 (14) |
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(PhysOrg.com) -- NASA's first-ever moon temperature-mapping effort has returned its first data.
NASA's LCROSS Reveals Target Crater For Lunar South Pole Impacts
Space & Earth / Space Exploration
Sep 11, 2009 |
4.6 / 5 (8) |
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(PhysOrg.com) -- NASA has selected a final destination for its Lunar Crater Observation and Sensing Satellite, or LCROSS, after a journey of nearly 5.6 million miles that included several orbits around Earth ...
Will Kepler find habitable moons?
Sep 03, 2009 |
5 / 5 (14) |
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(PhysOrg.com) -- Since the launch of the NASA Kepler Mission earlier this year, astronomers have been keenly awaiting the first detection of an Earth-like planet around another star. Now, in an echo of science ...
