At least 5,000 years, the earthlings were impressed with full solar eclipses. But once this phenomenon can be a folklore-well, 600 million years, plus minus.
About every 18 months the month completely blocks the sunlight somewhere on the earth, creating a complete solar eclipse. One is even planned for April in the United States, when tens of millions of people can feel this phenomenon.
Enjoy it while you can, because the moon is moving away from Earth - about 3.8 centimeters (1.5 inches) every year, according to NASA. When the average distance from the ground increases by another 14,600 miles, it will be too far to completely close the sun from the Earth's point of view.
"3.8 centimeters a year may not mean much to anyone," said Noah Peter, a scientist from NASA. "When you add it for a lifetime, for thousands or millions of years, it is added."
Complete solar eclipses are a celestial miracle. The diameter of the sun is about 400 times larger than the diameter of the moon, but by accident it is 400 times from the Earth than a month. These eclipses occur when the angular size of the moon (the amount of space it takes in your review) is largely the same as the angular size of the sun. As the moon moves further, its angular size will seem smaller.
Assuming that the moon will continue to move away at the current speed - which is a great assumption, Petro said - the month will be 14,600 miles (23,000 kilometers) in about 600 million years. But given that the sun is expected to grow at this time, full solar eclipses may disappear a little earlier.
Scientists have discovered this slow drift, experimenting with the reflective panels made from the mirrors that remained on the month after Apollo missions. For decades, they sent a ray of light to the reflectors and determined the time at which the light returned to the Earth. They found that a laser journey is a little extended every year, that is, the moon moves further into space.
The rotation of the Earth, the orbit of the moon and the rotation of the moon are interconnected and form the angular moment of the land-moon system, said physicist Richard Olenik. The angular moment remains constant for sufficiently isolated systems such as land and moon; So, if the rotation of the Earth changes, the orbit of the moon will change. (Think about how the angular moment of the figure skater is stored when it pulls hands and rotates faster.)
The rotation of the Earth is slowed down by the gravity of the moon (although it decreases by only about 1.4 milliseconds per centuries). This is because the moon pulls the earthly tides and outflows, and the oceans of the planets protrude to it. These tidal bulges create resistance and slow down the rotation of the Earth.
To compensate for the slowdown of the rotation of the Earth, the orbit of the moon becomes greater, said Olenik, Professor of the University of Dallas. The moon also rejects a smaller shadow on the ground.
"Since the tides and outflows are a bit different, one of the ways of energy comes to the moon is that it is slowly moving away," Peter said.
The moon probably drifted from the very beginning of its existence. It is believed that the moon was formed from debris after a large object in the size of Mars collided with the young land about 4.5 billion years ago. According to Peter, modeling implies that the moon could be at a distance of 15,000 miles (24,000 kilometers) after its formation. From that moment, the moon was slowly moving away, although speed was likely to fluctuate during history when the Earth and its gravitational attraction changed.
“It happens so gradually. It would not be the way someone wakes up once and says, "Oh, wait a moment." What happened here? ”Petro said.
If after 600 million years there are still human generations on Earth, they will see only a "fiery ring" or annular eclipse, when the moon passes by the sun, but does not close it completely. The moon may also look a little smaller, probably as we see the moon now at the farthest point of orbit.
When the moon is removed, the "duration" of the earth's day will also change slowly over time, Peter said. Olenik said that the angular speed of the moon should also slow down, keeping in mind that it would take more time to go through their phases. The tides on the ground will also be smaller as the gravitational attraction of the moon will be weaker.
And perhaps objects will look a little differently than a month.
"I would like to think that in 600 million years we will also have people on the moon, looking back to the ground," Petro said. "And so the earth will become a little smaller."
