Or Luna, is Earth’s only natural satellite. It is the fifth largest moon in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth diameter.
- Distance to Earth: 384,400 km
- Radius: 1 737.4 km – (Earth’s radius is 6,371 km)
- Orbital period: 27 days – (Earth’s orbital period is 365 days)
- Age: 4.53 billion years – (Earth’s age is 4.543 billion years)
- Gravity: 1.62 m/s² – (Earth’s gravity is 9.807 m/s²)
- Density: 3.34 g/cm³ – (Earth’s density is 5.51 g/cm³)
How did the moon formed
Most planetologists (those who study planets) agree that the Moon was formed by the impact with the Earth of an object roughly the size of Mars (Mars is about half the size of Earth), called Theia, right in the early days of our planet’s birth. In reality there are still many unknowns about the details of this event.
While scientists and onlookers wait impatiently for the countdown of the Artemis mission to resume, which will take us back to lunar orbit, we return to talk about the origins of our satellite. The Arthemis mission takes place on November 16, 2022 at 8:47 AM GMT+2.
Are we loosing our moon
By studying sedimentary layers, researchers have deduced valuable information about the distance between the Earth and the Moon. They showed that 2.46 billion years ago, our satellite was much closer to us, so that days only lasted 17 hours.
In 1969, during the Apollo missions, a reflector was installed on the surface of our satellite with the aim of being able to measure the Earth-Moon distance using a laser. Since then, it has been found that the average distance between us increases by 3.8 cm each year. An effect due to the dissipation of the tides, especially in the oceans, which tends to move the Moon away from the Earth. But if this value of 3.8 cm is projected into the past, we arrive at an origin only 1.5 billion years ago.
The Moon is an object of multi-millennial beliefs
Alternately god or goddess, the Moon has many names. From ancient Mesopotamia, she was embodied by the god Sîn among the Assyrians, or Nanna(r) for the Summerians, and gave birth to the Sun god, Shamash/Utu. The city of Ur, one of the largest cities of ancient Mesopotamia (located in present-day Iraq), venerates the moon-god Sîn more than 3,000 years before our era.
In the West, we are more accustomed to hearing about their Greek or Roman versions. The Greeks thus call her Selene, daughter of the Titans Hyperion and Theia, sister of Helios (the Sun) and Eos (the Dawn). She represents the full moon and is the second member of a triad made up of Artemis, the crescent moon, and Hecate, the new moon. For their part, the Romans baptized this goddess Luna.
6 Fun fact about the moon
Its diameter is equivalent to the lenght of China
The numbers don’t lie. In width, China measures 3,530 km; the Moon has a diameter of 3,476 km.
The moon is as wide as the United States as well. From the west to the east coast, the whole United States can fit on the moon. If you measure the moon’s surface area, we could fit all of Europe, China, the United States, Brazil, and South Africa altogether! The moon’s surface area is about 15.9% of Earth’s overall land area (excluding the area of Earth covered by oceans).
Neil Armstrong’s footprint and the flag
Because on the Moon there are no atmospheric agents that could erode the soil, no air, no rain or wind, on July 20, 1969, when Man took his first steps on the Moon, and the American astronaut who set foot on the lunar soil left a footprint there that is still visible on the surface.
On July 21, 1969, Neil Armstrong, then Buzz Aldrin, pose in their spacesuit next to an American flag. A few weeks before the fiftieth anniversary of the first steps of Man on the Moon, someone wondered the question of the possibility of the flag posed and floating on the satellite of the Earth. For that they had to put a horizontal bar on the flag. We do not see it well, but if we look more closely at the flags of the Apollo missions, we see this cheat.
The Moon causes the tides
The lunar gravity in fact slows the rotation of the Earth, influencing the oceans. Anyone who has seen the film Bruce Almighty may already know it: the lunar gravity exerts such an attraction on our planet that it causes tides. How strong is this attraction? Let’s put it this way, if there were no moon our days would only last 6 hours!
The tide is a direct application of Newton’s law of gravitation. It is generated by the action of the Moon and the Sun, which combine their forces to “attract” the masses of water from the earth – a bit like a magnet, even if the phenomenon is not magnetic.
The moonquakes
In recent period it has been discovered that there is regular seismic activity on the Moon. Moonquakes (as they are named) mostly occur when the moon’s crust, which is freezing due to two weeks of freezing nights, expands with the heat of the day. It is the so-called phenomenon of solid tides, which unlike the Earth, where the oceans prevent earthquakes from lasting more than a few minutes, on the moon they can last up to ten minutes.
The almost habitable subsoil of the moon
In the coming decades, multiple space agencies are planning to send astronauts to the lunar surface. More than that, there are multiple plans to construct permanent outposts on the Moon. Perhaps the best-known of these is the plan to build an International Lunar Village.
It starts in Japan, a space agency has recently discovered under the lunar surface a tunnel 50 km long and 1000 meters high, witch could be large enough to house an entire city, remaining sheltered from meteorites, cosmic rays and the very strong temperature range, which during the day it reaches a boiling hot 120°C and at night it can drop to -130°C. This space under the surface can certainly be more habitable for the man on the surface.
The Sun and the Moon look the same size in the sky, but they are not.
This happens beacuse from Earth the Moon is 400 times closer than the Sun, and the Sun is 400 times bigger than the Moon.
A solar eclipse occurs when the Moon passes between Earth and the Sun, given the fact that they look to us in the sky to be the same size, the Moon thereby obscuring the view of the Sun from a small part of the Earth, totally or partially.
