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China's plans to solve the mysteries of the moon

Fifty years ago, on July 20, 1969, the world watched as Neil Armstrong walked on the Moon. Since then, space agencies around the globe have sent rovers to Mars, probes to the furthest reaches of our galaxy and beyond, yet ...

50 years ago, humanity's first steps on another world

Fifty years ago on Saturday, American astronauts Neil Armstrong and Buzz Aldrin became the first humans in history to set foot on the Moon, an event watched on television by half a billion people.

Lunar rocks debunk moon landing conspiracy theories

Rocks collected from the moon 50 years ago and analyzed by an international team of scientists, including from the Australian National University (ANU), dispel any notion that the lunar landing was faked, an ANU expert says.

Marsquakes rock and roll

Fifty years after Apollo 11 astronauts deployed the first seismometer on the surface of the moon, NASA InSight's seismic experiment transmits data giving researchers the opportunity to compare marsquakes to moon and earthquakes.

Powering the future with lunar soil

Building a lunar base would be one of the next logical steps in our exploration of the solar system, but the survival of a future crew depends on access to a reliable source of energy. An ESA Discovery & Preparation study ...

What Artemis will teach us about living, working on the moon

Humans have not had much of an opportunity to work on the moon. The 12 Apollo astronauts who got to explore its surface clocked in 80 hours in total of discovery time. From their brief encounters, and from extensive analyses ...

Why the moon is such a cratered place

Look up on a clear night and you can see some circular formations on the face of our lunar neighbour. These are impact craters, circular depressions found on planetary surfaces.

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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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