The Moon has been a close companion of the Earth since time immemorial, and while our view of its shape and size varies somewhat as it orbits our planet, its presence is always and continuous in the sky.
But could that change?
In the movie Moonfall, which was broadcast a few days ago, specifically on the fourth of February, a mysterious force drives the moon out of its orbit around the Earth and pushes it on a collision course towards us, with a potentially devastating effect on our planet looming on the horizon, within a few weeks. .
Faced with the scenario of an impending catastrophe and the resulting dangers, the film's characters scramble to save the planet and while doing so, they learn that our natural satellite is not at all natural.
The idea of the Moon as a giant artificial structure built billions of years ago by intelligent extraterrestrials is firmly rooted in the realm of science fiction.
However, is there any natural object in space that can really push the moon out of its orbit?
With tens of thousands of asteroids and comets orbiting the solar system, could a collision with a large enough rock turn the moon into a projectile that could hit the Earth?
In the movie, the characters know that our natural satellite is not at all natural (IMDB).
Can the moon be moved from its orbit?
According to Newton's first law, a moving object continues to move unless something pushes or pulls it.
The orbits occur as a result of the perfect balance between the forward motion of an object in space, here the Moon, known as inertia, and the gravitational pull on it by another object in space, here the Earth.
These inertial and gravitational forces must be perfectly balanced in order for the object to remain in orbit.
And if the perfect balance between the moon's inertia and its gravitational pull were to change, the orbit would fail.
This can happen when the moon collides with something in space, and it gains or loses speed, depending on the direction of the collision. If the moon slows down, it will collide with the Earth.
Many scientists believe that such an impact was responsible for the death of the dinosaurs and many other types of life 65 million years ago, when a meteor hit the Earth.
How is the moon formed?
According to a report published in the Live Science website, our moon is a solid rocky body surrounded by a very thin layer of gases known as the atmosphere, and the moon was formed around the same time as the earth, about 4.5 billion years ago.
A widely accepted hypothesis is that the Moon is made of rocky debris from a massive collision between Earth and a smaller planet, a hypothetical being called Theia.
NASA also says that there is another hypothesis about the collision that both the Moon and the Earth formed after the collision of two bodies, each 5 times the size of Mars.
The moon is located about 385,000 km from Earth, and its mass is estimated at more than 81 million tons, which is almost a quarter of the Earth's size.
A hypothesis indicates that the moon was caused by a collision between the Earth and a smaller planet called Theia (websites)
very low probability
Images of the moon show that its surface is riddled with craters of various sizes, resulting from collisions in the past.
Most of these things first formed billions of years ago, when there was a lot of debris flowing through the air, says Paul Chodas, director of the Center for Near-Earth Object Studies (CNEOS) for NASA's Jet Propulsion Laboratory at the California Institute of Technology (Caltech) in Pasadena, California. Solar System.
Most of the planet-forming rocky debris that once filled the solar system has long since dissipated, Chodas tells Live Science, "so the number of impacts has gone down a lot now, there's a lot less material to affect the Earth or the Moon."
The Center for Near-Earth Object Studies (CNEOS) identifies asteroids and comets, to determine if they pose a threat to Earth or the Moon.
The center is currently tracking the movement of about 28,000 objects approaching the Earth within 194.5 million km.
“In general, asteroids are much less likely to hit the Moon than Earth, because our planet is a more massive target and has a stronger gravitational pull that is able to attract objects to it,” Chodas says. So a space rock that might veer off course and come in our neighborhood will be pulled toward Earth instead of the moon.
When you look at the moon you can feel comfortable that it's not going anywhere anytime soon (NASA)
What is the size of the objects threatening the moon?
The size of objects hurtling toward Earth or the Moon is taken into account when scientists think about the danger posed by an asteroid hurtling toward us.
According to NASA, NEOs are classified as a threat to us when they are at least 140 meters in diameter.
As for the moon, for an asteroid impact to affect its orbit, it must be at least as large as the moon itself.
Fortunately for us on Earth and for the Moon of course, there are no known asteroids in the Solar System close to the size of the Moon, anywhere near.
According to NASA, the largest known asteroid with a mass less than 70 times that of the Moon, orbits between Mars and Jupiter in the main asteroid belt, about 180 million km from Earth.
The surface of the moon is filled with craters of various sizes resulting from collisions in the past (NASA)
Does the moon move from its place a man-made object?
The possibility of an asteroid from the solar system displacing the moon might be ruled out, but what about a man-made object?
For example, the booster stage of the expendable SpaceX Falcon 9 rocket that was launched in 2015 is currently on a collision course with the moon, and it is expected to collide with it in March 2022, and this collision will result in a crater with a diameter of about 20 meters, according to Live Science in a previous report.
There is no risk of such an impact affecting the Moon's orbit.
So, the next time you look at the moon in the night sky, you can take comfort from the thought that it's not going anywhere anytime soon.