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 ...
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 |
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 |
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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.
China to launch second lunar probe: state media
Space & Earth / Space Exploration
Nov 27, 2009 |
5 / 5 (5) |
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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.
Fantastic Voyage
Space & Earth / Space Exploration
Nov 02, 2009 |
4.8 / 5 (19) |
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By travelling to the outer solar system, the two Voyager spacecraft allowed us to see amazing details of far-distant planets and moons.
NASA: Booster rocket damaged in test flight
Space & Earth / Space Exploration
Oct 29, 2009 |
3 / 5 (6) |
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(AP) -- NASA says the booster rocket used in a test flight was badly dented when it fell into the Atlantic.
New Celestial Map Gives Directions for GPS
Space & Earth / Space Exploration
Oct 29, 2009 |
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(PhysOrg.com) -- Many of us have been rescued from unfamiliar territory by directions from a Global Positioning System (GPS) navigator. GPS satellites send signals to a receiver in your GPS navigator, which ...
Cassini Sends Back Images of Enceladus as Winter Nears
Space & Earth / Space Exploration
Nov 23, 2009 |
4.4 / 5 (7) |
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(PhysOrg.com) -- NASA's Cassini spacecraft has sailed seamlessly through the Nov. 21 flyby of Saturn's moon Enceladus and started transmitting uncalibrated temperature data and images of the rippling terrain. ...
Before Darkness Falls: Cassini to Scan Enceladus on Winter's Cusp
Space & Earth / Space Exploration
Nov 20, 2009 |
4.5 / 5 (2) |
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(PhysOrg.com) -- NASA's Cassini spacecraft will fly by Saturn's moon Enceladus this weekend for a last peek at the intriguing "tiger stripes" before winter darkness blankets the area for several years.
Discoveries in the Deep
Space & Earth / Earth Sciences
Nov 12, 2009 |
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Scientists from NASA and the Canadian Space Agency have been using Pavilion Lake as a testing ground for the future human exploration of other worlds.
Successful Flight Through Enceladus Plume (w/ Video)
Space & Earth / Space Exploration
Nov 04, 2009 |
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(PhysOrg.com) -- Cassini has started sending data back from its Nov. 2 flyby of Saturn's moon Enceladus.
STAR TRAK for November: Mars is prominent again
Space & Earth / Space Exploration
Nov 02, 2009 |
4 / 5 (2) |
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(PhysOrg.com) -- Pumpkin-colored Mars will return to prominence during November, rising shortly before midnight at the beginning of the month and more than two hours earlier by month's end. The orange planet ...
