Moon
is shown as the beautiful circular light from the Earth. Therefore, in the past
time, human realized that the earth is a holy thing. So many people have the
great mythology about moon. Some of them call the moon as God, and any other
mythology. This is happen because the moon just shown as far object that cannot
be reached by human in that time.
The
Moon is Earth's only natural satellite and the fifth largest satellite in the
Solar System. It is the largest natural satellite in the Solar System relative
to the size of its planet, a quarter the diameter of Earth and 1/81 its mass,
and is the second densest satellite after Io. It is in synchronous rotation with
Earth, always showing the same face; the near side is marked with dark volcanic
Maria among the bright ancient crustal highlands and prominent impact craters.
It is the brightest object in the sky after the Sun, although its surface is
actually very dark, with a similar reflectance to coal. Its prominence in the
sky and its regular cycle of phases has since ancient times made the Moon an
important cultural influence on language, the calendar, art and mythology. The
Moon's gravitational influence produces the ocean tides and the minute
lengthening of the day. The Moon's current orbital distance, about thirty times
the diameter of the Earth, causes it to appear almost the same size in the sky
as the Sun, allowing it to cover the Sun nearly precisely in total solar
eclipses.
The
Moon is the only celestial body on which humans have landed. While the Soviet
Union's Luna program was the first to reach the Moon with unmanned spacecraft in
1959, the United States' NASA Apollo program achieved the only manned missions
to date, beginning with the first manned lunar orbiting mission by Apollo 8 in
1968, and six manned lunar landings between 1969 and 1972—the first being Apollo
11 in 1969. These missions returned over 380 kg of lunar rocks, which have been
used to develop a detailed geological understanding of the Moon's origins (it is
thought to have formed some 4.5 billion years ago in a giant impact event
involving Earth), the formation of its internal structure, and its subsequent
history.
After
the Apollo 17 mission in 1972, the Moon has been visited only by unmanned
spacecraft, notably by Soviet Lunokhod rovers. Since 2004, Japan, China, India,
the United States, and the European Space Agency have each sent lunar orbiters.
These spacecraft have contributed to confirming the discovery of lunar water ice
in permanently shadowed craters at the poles and bound into the lunar regolith.
Future manned missions to the Moon are planned but not yet underway; the Moon
remains, under the Outer Space Treaty, free to all nations to explore for
peaceful purposes.
