The Moon is an astronomical body that orbits planet Earth and is Earth’s only permanent natural satellite. It is the fifths largest natural satellite in the Solar System, and the largest among planetary satellites relative to the size of the planet that it orbits (its primary). The Moon is after Jupiter’s satellite To the seconds densest satellite in the Solar System among those whose densities are known .The Moon is thought to have formed about 4.51 billion years ago, not long after Earth. The most widely accepted explanation is that the Moon formed from the debris left over after a giant impact between Earth and a Mars seized body called Theia.
The Moon is in synchronous rotation with Earth, and thus always shows the same side to Earth, the near side. The near side is marked by dark volcanic maria that fill the spaces between the bright ancient crustal highlands and the prominent impact craters. After the Sun, the Moon is the seconds brightest regularly visible celestial object in Earth’s sky. Its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its gravitational influence produces the ocean tides, body tides, and the slight lengthening of the day.
The Moon’s average orbital distance is 384,402 km (238,856 ), or 1.28 lights seconds. This is about thirty times the diameter of Earth. The Moon’s apparent size in the sky is almost the same as that of the Sun, since the star is about 400 times the lunar distance and diameter. Therefore, the Moon covers the Sun nearly precisely during a total solar eclipse. This matching of apparent visual size will not continue in the far future because the Moon’s distance from Earth is gradually increasing.
The Moon was first reached in September 1959 by the Soviet Union’s Luna 2, an unmanned spacecraft. The United States’ NASA Apollo program achieved the only manned lunar missions to date, beginning with the first manned orbital mission by Apollo 8 in 1968, and six manned landings between 1969 and 1972, with the first being Apollo 11 in July 1969. These missions returned lunar rocks which have been used to develop a geological understanding of the Moon’s origin, internal structure, and the Moon’s later history. Since the 1972 Apollo 17mission the Moon has been visited only by unmanned spacecraft.
Both the Moon’s natural prominence in the earthly sky and its regular cycle of phases as seen from Earth have provided cultural references and influences for human societies and cultures since time immemorial. Such cultural influences can be found in language, lunar calendar systems, art, and mythology.
17 great fact of a moon
1 The Moon is the Earth’s only natural satellite. A natural satellite is a space body that orbits a planet, a planet like object or an asteroid.
2 It is the fifth largest moon in the Solar System. Learn more about the other moons in the Solar System.
3 The average distance from the Moon to the Earth is 384403 kilometres (238857 miles).
4 The Moon orbits the Earth every 27.3 days.
5 Mons Huygens is the tallest mountain on the Moon, it is 4700 metres tall, just over half the height of Mt Everest (8848m).
6 The Moon rotates on its axis in around the same length of time it takes to orbit the Earth. This means that from Earth we only ever see around 60% of its surface (50% at any one time).
7 The side that we can see from Earth is called the near side while the other side is called the far side (it is sometimes called the dark side despite the fact that it illuminated by the Sun just as much as the near side).
8 The effect of gravity is only about one fifth (17%) as strong on the surface of the Moon compared to the strength of gravity on the surface of the Earth.
9 The Soviet Union’s Luna program featured the first successful landing of an unmanned spacecraft on the surface of the Moon in 1966.
10 The USA’s NASA Apollo 11 mission in 1969 was the first manned Moon landing.
11 The first person to set foot on the Moon was Neil Armstrong.
12 The far side of the Moon looks quite different due to its lack of maria (ancient pools of solidified lava).
13 The surface of the Moon features a huge number of impact craters from comets and asteroids that have collided with the surface over time. Because the Moon lacks an atmosphere or weather these craters remain well preserved.
14 Although research is continuing, most scientists agree that the Moon features small amounts of water.
15 The Moon is very hot during the day but very cold at night. The average surface temperature of the Moon is 107 degrees Celsius during the day and -153 degrees Celsius at night.
16 The Earth’s tides are largely caused by the gravitational pull of the Moon.
17 The phases of the Moon are: New Moon, Crescent, First Quarter, Waxing Gibbous, Full Moon, Waning Gibbous, Last Quarter, Crescent, New Moon…