How Long Does it Take the Moon to Orbit the Earth?
How long does it take the moon to orbit the earth? It takes the moon 27.322 days to orbit the Earth.
It takes the moon 27.322 days to orbit the Earth and this orbit is almost circular. The moon is the fifth largest moon in the solar system and is bigger than the dwarf planet Pluto. The moon’s average distance from Earth is 384,400 km or 238,855 miles.
Orbits and Rotations
While the moon is orbiting the Earth, it is also rotating. Its rotation is the same length as its revolution, or orbit. That means that we never see the other side of the moon. This is due to the effect of tidal forces.
The gravity of both the Earth and the moon attract one another. The force of the moon’s gravity is stronger on the side of the Earth that is facing the moon and weaker on the other side of the Earth.
Planets are not solid and therefore change shape. For example, the Earth bulges at the equator because it spins. Planets can also change shape because of tidal forces and this causes the tides of the oceans to rise and fall.
Other Moons
Since you know that it takes the moon almost a month to orbit the Earth, you might be wondering about the other moons of our solar system:
- Venus and Mercury have no moons
- Mars has two
- Jupiter has 63
- Saturn has 60
- Uranus has 27
- Neptune has 13
The shortest orbit of any moon is 0.295 days, made by the moon Metis of the planet Jupiter. The longest orbit of any moon is 9,136.11 days, made by the moon Psamathe of the planet Neptune.
Facts About the Earth’s Moon
Aside from knowing how long it takes the moon to orbit the earth, there are plenty of other facts about the moon to know as well.
- The radius of the moon averages 1,079.6 miles, which is around 27% of the Earth’s radius.
- The gravity of the moon is about 1/6 of the Earth’s. That means you would weigh much less on the moon and if you dropped something, it would fall much slower than here on Earth.
- The average distance from the center of the Earth to the center of the moon is 238,897 miles.
- The temperature of the moon ranges from -280 degrees F to 260 degrees F.
When you look at the moon:
- The lighter areas are called terrae, which is Latin for “lands.” These are the rugged highlands which were the original crust of the moon. They are full of craters from asteroids, meteoroids, and comets.
- The darker areas are called maria, which is Latin for “seas”. Since these areas are smooth and dark, they look like seas. They are actually cratered landscapes that were flooded with lava from volcanoes. When the lava froze, it became dark rock.
Also when you look at the moon, you will notice its phases. They are: full, first quarter, last quarter, and new moon. These appear because you see a different section of the lit side of the moon every day. When the moon is between the Sun and the Earth, its lit side is facing the Sun. Since it is dark, this is called a new moon. As the moon phases from new moon to full moon, it is said to be waxing. Going from full moon to new moon is waning.
Exploration of the Moon
Un-manned spacecraft began exploring the moon in 1959. The Luna 3 from the Soviet Union took the first pictures of the dark side of the moon. The United States Apollo 11 lunar module named the Eagle landed on the moon on July 20, 1969, and Neil Armstrong became the first human to step on the moon.
Two United States space probes, named Clementine and Lunar Prospector, found frozen water at the poles of the moon. Scientists believe the water came from comets that hit the moon in the past. The ice was found in the shadows of crater rims that the Sun’s light never touches.