What are the characteristics of the super moon?

Supermoon refers to the state that the moon is close to the earth. On March 19th, 211, the moon reached the closest position to the earth in 19 years, and its distance from the earth was only over 35, kilometers. Seen from the earth, the moon's area increased by 14% and its brightness increased by 3% compared with apogee, so it is called "super moon". The "Super Moon" in 212 appeared in the night sky on May 6th.

The so-called super moon does not exist in astronomical research, which was first put forward by western astrologers. Generally speaking, it refers to the relatively close state of distance to the moon Earth, and generally only refers to the moon at the moment of perigee. The appearance of "super moon" is determined by the orbit of the moon. Like the orbits of many celestial bodies, the relative orbit of the moon around the earth is elliptical. Therefore, the distance between the moon and the earth is not fixed when it revolves around the earth.

generation principle: overview of the moon The moon is the only satellite of the earth. The precise measurement of the moon and the earth's rocks shows that the age of the moon was 4.5 billion years, while the age of the earth was about 4.48 billion years. The rocks on the surface of the moon are generally older than 3.1 billion years, indicating that the evolution of the moon was mainly carried out by the super moon within 1.5 billion years after its formation. At present, the moon is a celestial body with nearly exhausted internal energy and nearly dead activity, with only extremely weak lunar earthquake activity. The mass of the moon is about 1/81 of that of the earth, and the average density of the moon is 3.34 g/cm3, which is only 6% of the average density of the earth. The average composition of the moon and the earth is very different. The moon is richer in refractory elements than the earth, but lacks volatile elements and iron-affinity elements. The moon lacks water and is more reductive than the earth. The revolution of the moon revolves around the mass center of earth-moon system mass, and the revolution plane of the moon is not consistent with the equatorial plane of the earth.

People's understanding of the moon is deepening. In January 211, scientists revealed that the structure of the moon is somewhat similar to that of the earth by analyzing the signals sent back by the seismic probe placed on the moon by Apollo in 1971. There is also a layered structure of core, mantle and shell inside the moon. The core of the moon is a solid with a radius of nearly 15 miles (about 241 kilometers), and it is surrounded by a liquid outer core with a radius of about 25 miles (about 33 kilometers). Different from the Earth, there is a partially molten boundary layer with a radius of nearly 3 miles (about 482 kilometers) outside the lunar core. The point from the Earth to the Moon that is closest to the Earth in its orbit is called perigee, and vice versa. Every time the moon revolves around the earth, it will pass through a perigee and an apogee. According to measurements, when the moon is at perigee, the average distance from the earth is 363, kilometers, while when it is at apogee, the average distance is 46, kilometers, with a difference of 1.41%. Therefore, if you look closely, it is not difficult to find that the moon is much bigger when it is at perigee than when it is at apogee. On March 19, 211, the distance between the moon and the earth was only 357, kilometers, which was 1.84% closer than the average distance of perigee, so it would look even bigger.

When the moon goes around the earth, its orbit is an ellipse, so the distance between the perigee moon and the apogee moon between the moon and the earth is constantly changing, and the size of the moon seen by people will be different. When the moon moves to perigee, the moon is closest to the earth at this time, and the moon people see on the earth is the largest and brightest in the current cycle. Because the orbital plane is close to the ecliptic plane, not near the equatorial plane of the earth, and earth-moon system is a complex system influenced by many celestial bodies, the orbits of this Shuoyue (the shortest effective time between two identical moon phases) and the next Shuoyue are bound to change. Among the perigee of several Shuoyue, there must be one that is close to the earth's surface, and it can be seen that it becomes the so-called "super moon". From previous astronomical data, it seems that the recorded time of the "super moon" is also regular

super moon

to follow; However, the standard of judging the distance between the earth and the moon is not so easy to grasp, and there is no so-called critical distance. It seems that we can only implement the "case law" according to the previous statement. And this ruling power is often in the influential media, which has a certain degree of subjectivity and speculation. The concept of "super moon" is "too vague" and not "bright" at all.

Astronomers calculated by simulation that on March 19th, 211, the perigee of the moon was only 221,567 miles (about 356, kilometers) away from the Earth. As we already know, the average distance between the earth and the moon is 384,4 kilometers, which is about 6 times that of radius of the earth. The perigee is 3633 kilometers, the apogee is 455 kilometers, and the eccentricity is about .547.