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
Pioneering images of both martian moons (w/ Video)
Space & Earth / Space Exploration
14 hours ago |
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(PhysOrg.com) -- For the very first time, the martian moons Phobos and Deimos have been caught on camera together. ESA's Mars Express orbiter took these pioneering images last month. Apart from their ‘wow’ ...
Scientists explain puzzling lake asymmetry on Titan
Space & Earth / Space Exploration
Nov 29, 2009 |
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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 ...
STAR TRAK for December: Geminid meteors flash in December skies
Space & Earth / Space Exploration
Dec 03, 2009 |
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(PhysOrg.com) -- The annual Geminid meteor shower, which will reach its maximum on the night of Dec. 13-14, usually offers the best show of the year, outperforming even the Perseid shower of August. This year ...
NASA puzzled why parachutes failed in rocket test
Space & Earth / Space Exploration
Dec 03, 2009 |
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(AP) -- NASA still isn't sure why two parachutes failed during a test flight of its prototype moon rocket just over a month ago.
LCROSS Impact Finds Water on the Moon
Space & Earth / Space Exploration
Nov 13, 2009 |
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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 ...
China to launch second lunar probe: state media
Space & Earth / Space Exploration
Nov 27, 2009 |
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China will launch its second moon orbiter next October, state media reported Friday, as it powers ahead with a space programme that has sparked concerns abroad.
Red Sea coral seen to feed on jellyfish
Nov 17, 2009 |
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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 |
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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 ...
Jupiter's Moon Europa Has Enough Oxygen For Life
Space & Earth / Earth Sciences
Oct 16, 2009 |
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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 ...
Partial lunar eclipse will take place on 31st December
Space & Earth / Space Exploration
Dec 03, 2009 |
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(PhysOrg.com) -- In a lunar eclipse, the Earth, Sun and Moon are almost exactly in line and the Moon is on the opposite side of the Earth from the Sun.
2 parachutes malfunctioned in NASA test flight
Space & Earth / Space Exploration
Oct 30, 2009 |
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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 |
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(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.
How the Moon produces its own water
Space & Earth / Space Exploration
Oct 15, 2009 |
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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 ...
Scientists Make Oxygen Out of Moon Rock
Space & Earth / Space Exploration
Aug 11, 2009 |
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(PhysOrg.com) -- If humans ever create a lunar base, one of the biggest challenges will be figuring out how to breathe. Transporting oxygen to the moon is extremely expensive, so for the past several years ...
