Why is the moon's orbit around the earth elliptical?

elliptic orbit
Suppose you climb the East peak of Huashan Mountain, stand on the Chaoyang platform, throw a stone horizontally, and you will see it quickly fall down the mountain. You may see it hit a place under the peak. At this time, if you throw another stone that is almost the same size, if you can still see its landing point at the foot of the mountain, the landing point this time must be farther than the previous one, Because you used more force
This is based on the fact that gravity exerts a downward pull on an object, and the pull changes the motion state of the object. The downward speed generated by the pull is the same, so the time for two stones to move from the mountain to the foot is the same. But with different forces, the speed of the stone in the horizontal direction is also different, so the distance of their horizontal movement in the same time must be different
Another fact is that the earth is round. In the distance of the object falling, the earth's surface also bends downward, so the actual falling point is farther than the falling point on the horizontal plane. If the object's speed can be made large enough, when it falls 1 meter toward the ground, the surface also bends 1 meter downward, and the height between it and the ground remains unchanged, so it will never land, It produces a circular orbit concentric with the earth's surface
The ability to keep the orbit motion depends on the speed of moving forward along the surface curve, which must ensure that the object will not fall to the ground. As the object with higher height is less affected by gravity than the object with lower height, the speed of keeping the circular orbit can be reduced when the height increases
If the object is allowed to get a higher speed, within the time of falling 1 meter, the forward movement distance is enough to reach the place where the surface bends down 2 meters, so that the distance from the object to the surface actually increases, that is, the height increases. If the object continues to move, the height increases continuously, but due to the effect of gravity, the upward object gradually slows down, and after circling the earth for half a circle, the height increases, At last, the ball returns to its original position, returns to its original speed, and starts its original motion again, thus forming an elliptical orbit
The understanding of elliptical orbit is in line with our general understanding. If you throw a stone into the air, it starts to slow down when climbing, slows down when climbing to the highest point, and then it rushes to the ground and starts to pick up again
The velocity of an elliptical orbit
Eccentricity value perigee velocity
The speed of each point in the 0 (circular) orbit is equal
122% of apogee velocity, 105% of circle velocity
186% of apogee velocity, 114% of circle velocity
300% of apogee velocity, 122% of circle velocity
567% of apogee velocity, 130% of circle velocity
0.9 1900% of apogee velocity 138% of circle velocity
Eccentricity is used to measure the shape of an ellipse. The larger the eccentricity is, the flatter the ellipse is. The eccentricity of an ellipse is between 0 and 1. The eccentricity can be calculated by dividing the distance between focuses by the length of the major axis

Was the moon's early orbit elliptical?

In 1799, Laplace, a famous French mathematician, discovered a strange phenomenon when calculating the mass of the moon: the mass of the equatorial region of the moon is too large. Later astronomical observations also confirmed that the mass of the equatorial region of the moon is too large, The equatorial region of the moon bulged out, which is known as the "Laplacian puzzle". Since then, the astronomical community has not been able to give a reasonable explanation for the "Laplacian puzzle". Most theoretical models either do not conform to the orbit of the moon, or do not conform to the size of the moon, "The Laplace puzzle" may indicate that the early orbit of the lunar sphere was different from that of the present. They said that when the moon was about 100 million years old, its orbit around the earth was probably elliptical. At this time, the lunar material had not yet fully solidified and would concentrate to the equatorial region, causing the deformation of the moon, It is like a sphere made of sticky molasses. When it moves around the earth in an elliptical orbit, it will deform and solidify under the influence of the earth and the sun, and finally become the shape of today. Chuber et al. Proposed several models of the early lunar orbit, one of which is the most consistent with the current state of the lunar sphere: about 100 million years after the birth of the moon, The first mock exam is that the moon's orbit is probably elliptical elliptical, like the orbit of mercury moving around the sun, and its rotation time is 3 times that of the 2 revolution. Astronomers say the model shows that the moon is very active at the early stage and can well meet the most convincing moon birth hypothesis at present. The hypothesis is that 24 times the earth's radius is about the same as the earth's orbit. More than 4 billion years ago, the early Earth collided with a planet the size of Mars, and the debris and molten material produced by the collision condensed into the moon

What is the shape of the earth's orbit?

The reason for the four seasons of a year is not the distance from the sun, but another reason. At the equinox, the sun shines on the equator, because the earth's axis is tilted, so with the revolution of the earth, the direct point of the sun slowly shifts northward, until the summer solstice, it just shines on the Tropic of cancer, after the summer solstice, the direct point of the sun moves southward

Why is the moon's orbit around the earth elliptical?