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After SpaceX, NASA taps Bezos's Blue Origin to build Moon lander

Two years after awarding Elon Musk's SpaceX a contract to ferry astronauts to the surface of the Moon, NASA on Friday announced it had chosen Blue Origin, a rival space company founded by billionaire Jeff Bezos, to build ...

Researchers announce 62 new moons of Saturn

The work of an international team of astronomers has resulted in the announcement of 62 new moons of Saturn, catapulting it back into first place of the "moon race" around the giant planets of our solar system.

NASA's Juno mission nears Jupiter's moon Io

NASA's Juno spacecraft will fly past Jupiter's volcanic moon Io on Tuesday, May 16, and then the gas giant itself soon after. The flyby of the Jovian moon will be the closest to date, at an altitude of about 22,060 miles ...

Building planetary systems that could last forever

Vacations can be quite enjoyable. Visiting historic cities, lounging in the sun on a tropical beach, or snuggling up at a cozy mountain resort. But while the destinations are great, traveling itself can be a chore. Crowds, ...

Thirsty on the moon? Just throw some regolith in the microwave

No matter where we go in the universe, we're going to need water. Thus far, human missions to Earth orbit and the moon have taken water with them. But while that works for short missions, it isn't practical in the long term. ...

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The 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.

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