The Moon in General Terms


Earth’s moon is the brightest object in our night sky and the closest celestial body. Its presence and proximity play a huge role in making life possible here on Earth. The moon’s gravitational pull stabilizes Earth’s wobble on its axis, leading to a stable climate.

Distance to Earth’s natural satellite “the moon” is appx 380,000 km away.

The moon’s orbit around Earth is elliptical. At perigee — its closest approach — the moon comes as close as 225,623 miles (363,104 kilometers). At apogee — the farthest away it gets — the moon is 252,088 miles (405,696 km) from Earth. On average, the distance from Earth to the moon is about 238,855 miles (384,400 km). However, the moon is moving away from Earth at a rate of about 1.5 inches (4 cm) per year.

The moon is in synchronous rotation with Earth. In other words, the moon rotates on its axis in about the same amount of time it takes to revolve around Earth — 27 days 8 hours, which is called sidereal month. So we always see the same side of the moon; there is no “dark side of the moon.” A lunar month, also called a synodic month, is the time it takes for the moon to complete a lunar cycle — full moon to full moon. A lunar month is about 29 days 13 hours.

How long does it take to get to the moon?

The time it takes to get to the moon depends on the speed of the spacecrafts. The Apollo 11 was launched July 16, 1969 from Kennedy Space Centre and landed on the moon on July 19th It took a total of 3 days, 3 hours and 49 minutes to fly to the Moon and 3 days to return to Earth. Afterwards, on April 11, 1970, Apollo 13 was launched from the Kennedy Space Centre and landed on the Pacific Ocean after traveling around the Moon on April 17th It took total of 5 days, 22 hours and 54 minutes to fly to the Moon and return back to Earth.
Apollo missions took about three days to reach the moon. But the quickest trip to the moon was the New Horizons probe, which zipped past the moon in just 8 hours 35 minutes on its way to Pluto. However, the spacecraft didn’t even slow down or approach lunar orbit. 

Tidal forces

Tides occur because of the gravitational pull of the moon. The oceans bulge in the direction of the moon. High tide happens when the moon is overhead, but it also happens on the opposite side of the planet because the moon is tugging on Earth as well.

Spring tides — so called because the water “springs up,” not because of the season — occur when the moon, the sun and Earth are aligned, during a full moon or new moon. The gravitational forces of the moon and the sun both contribute to these especially strong tides. Neap tides are weak and occur during quarter moons when the forces of the sun and the moon are perpendicular to each other.

Moon Factsmoon-2

  • Star Name: Moon
    Age: 4.5 billion years old
    Mass: 73’490’000’000’000’000 million kg
    Shape: Egg-shaped
    Family: Member of our solar system, satellite of earth
    Active Relationships: Orbits around the earth
    Distance from earth: 384’467 km (~364 397 km at perigee,~406 731 km at apogee)
    Traveling by car: 130 days
    Traveling by rocket: 13 hours
    Traveling by light speed: 1.52 sec
    Diameter: 3476 km (1/4 of the Earth’s)
    Driving around by car: 4 days
    Gravity acceleration: 1.62m/sec2 (1/6 of Earth’s)
    Revolution period: 27.3217 days
    Mean Synodic period (new moon to new moon): 29.530588861 days
    Mean orbital velocity: 1.023 km/sec

Rotation of moon
The same side of the Moon always faces the Earth. The Moon’s rotation period is synchronous with its revolution period around the Earth.

Change of distance
Because of a loss of orbital energy to gravity from the Earth, the Moon is very gradually moving away from the Earth. In the very early history of the Earth, the Moon looked about 3 times larger in apparent size in the sky, because it was closer to the Earth.

Lunar atmosphere
The Moon has almost no atmosphere, because of its weak gravity. All types of gas will escape from its surface.
Without an atmosphere, there is no wind or water erosion. The Moon’s surface is about the same now as it was 3 billion years ago. The astronauts’ footprints remain unchanged on the Moon’s surface. The footprints should last at least 10 million years.

Temperatures on the moon, dress code
The surface temperature fluctuates from roughly +300� F during the 2-week daytime to -270 F during the 2-week night. This is because there is not enough atmosphere to keep the Moon warm at night, nor protect it from the Sun’s rays in the daytime. If you are wondering what to wear, an astronaut’s suit is the most appropriate answer.  

The Apollo 11 mission to the moon

The Apollo 11 Saturn V space vehicle, at Launch Pad 39A, at the liftoff: 9:32 a.m. EDT, along with astronauts Neil A. Armstrong, Michael Collins and Edwin E. Aldrin Jr. 

During the planned eight-day mission, Armstrong and Aldrin descended in a lunar module to the Moon’s surface while Collins was orbiting overhead in the command module. The two astronauts spent 22 hours on the Moon, including two and one-half hours outside the lunar module. They gathered samples of lunar material and deployed scientific experiments.
They rejoined Collins at the command module for the return trip to Earth. 

The astronauts splashed down in the Pacific Ocean and recovery was made by the U.S.S. Hornet on July 24, 1969.

Just twenty seconds’ worth of fuel remained when Apollo 11’s lunar module landed on the moon.

The multi-layered space suit worn by astronauts on the Apollo moon landings weighed 180 pounds on Earth and 30 pounds on the Moon with the reduced lunar gravity.
The average desktop computer contains 5-10 times more computing power than was used to land a man on the moon.

The surface speed record on the Moon is 10.56 miles per hour. It was set in an Apollo lunar rover.

Size comparison
The volume of the Earth’s moon is the same as the volume of the Pacific Ocean.

Lunar magnetic field
The Moon has no global magnetic field. You cannot use a compass to find your direction.

Strange Mathematics: 1/2 equals 1/4
A quarter moon and a half moon are the same thing. The quarter refers to the fraction of the lunar month which has passed, whilst the half describes the portion of the Moon’s disc which is visible.

Calculation of the Easter date
Easter is the first Sunday after the first Saturday after the first full moon after the equinox. (The equinox is quite often March 21, but can also occur on the March 20 or 22.)

Tides and the moon
The moon causes many of the tides in the Earth’s oceans. This is because of the gravity force between the Earth and Moon. At full Moon and new Moon, the Sun, Earth and Moon are lined up, producing the higher than normal tides (called spring tides, for the way they spring up). When the Moon is at first or last quarter, smaller neap tides form.

Sun and Moon Eclipses
An eclipse of the Sun can occur only at New Moon, while an eclipse of the Moon can occur only at Full Moon.

Moon Ingredients
The moon is not made of cheese.

Legal status

# Buying land on the moon

Though several flags of the United States have been symbolically planted on the moon, the U.S. government makes no claim to any part of the Moon’s surface. The U.S. is party to the Outer Space Treaty, which places the Moon under the same jurisdiction as international waters. This treaty also restricts use of the Moon to peaceful purposes, explicitly banning weapons of mass destruction (including nuclear weapons) and military installations of any kind. A second treaty, the Moon Treaty, was proposed to restrict the exploitation of the Moon’s resources by any single nation, but it has not been signed by any of the space-faring nations.

Several individuals have made claims to the Moon in whole or in part, though none of these claims are generally considered credible.


A Shanepedia Compilation

Along with thanks and compliments to the sources for the shared data

Creative Commons Copyright © Shanepedia 2012