Astronomy knows nothing about the weather.

The super moon on May 7th will be the biggest and last time in 2020!

In fact, there will be four opportunities to watch the super moon in 2020. If you miss the first three times, don't forget the biggest super moon on the evening of May 7, which is the last chance to watch the super moon this year.

The best time to watch the super moon

From the evening of May 7th 18: 45, the moon moved to perigee, and at 2: 09 a.m. on April 8th, at 0: 35 a.m. on April 8th, the moon, the earth and the sun lined up in a straight line, during which everyone could see the super moon.

Of course, visually speaking, if you want to see the biggest and roundest moment of the moon, you'd better choose the time when the moon phase is full moon. The reason why everyone will see a bigger and brighter moon phase in the early morning of the 8 th is because the moon at that time will be the closest to the earth in a year.

Can this super moon be seen all over the country?

Different from other astronomical wonders, there are strict requirements on the position and observation time of the viewer. This super moon can be seen all over the country. There are only two prerequisites:

First, the so-called unpredictable weather, although no matter what weather you are in, can't stop the super moon from being staged, but bad weather like rain will inevitably lead people not to see this super moon.

Second: As long as the weather is fine, people everywhere can witness the super moon with their own eyes. Since there is no weather disturbance, we should take steps to go outdoors, and the super moon will definitely arrive on time. This time, both ordinary cameras and professional astronomical telescope equipment can easily capture the super moon in the sky.

? When is the next super moon?

In fact, the super moon is not a particularly rare astronomical spectacle. We can see from the historical data of previous years that the super moon can appear four or six times almost every year. For example, there were six super moons in 20 15, and four super moons in 2020.

If you miss the super moon again because of rain or other reasons, don't feel particularly sorry, because, about one year later, on May 26th, 20021year, we will welcome the next super moon.

The essence of super moon

Many people should not know that the word super moon was first put forward in 1979, not an astronomer, but a man named Richard? Noel's American astrologer. The essence of the super moon is actually the phase of the new moon or full moon after the moon moves near the perigee of the earth.

The reason why this special moon phase is called super moon is because when the local moon is close enough, the moon we see with the naked eye will be much bigger than usual (the perigee full moon will be larger than the apogee full moon 14%). In fact, not all astronomers think that the name super moon is reasonable, but it should be called perigee full moon more accurately.

The formation principle of super moon

As the only natural satellite on the earth, people have special feelings for it since ancient times. Although some studies show that the moon is gradually moving away from our earth, it is difficult for people to feel the basic fact that the earth and the moon have gradually drifted away if they are not placed on a longer time axis.

When we describe the distance between the earth and the moon, we usually use the word average distance, because the two planets are in constant motion and it is difficult to give an accurate distance value. In fact, just as our earth is an elliptical sphere, the moon's orbit around the earth is also elliptical. When the moon is in perigee and apogee, its average distance is 363,000 kilometers and 406,000 kilometers respectively.

The super moon actually comes from the difference between the near-earth distance and the far-earth distance of the moon 10.45438+0%, and the reason is very simple. For us who live on the earth, when the distance between the earth and the moon gets closer, it means that the moon we see will get bigger; When the distance between the moon and the earth becomes farther, then the moon we see will become smaller.

It is difficult for us to feel the change of the size of the moon at ordinary times, but when the super moon appears, we will obviously notice that the moon has become bigger, which is actually the visual difference caused by the distance difference of 5 kilometers.

How to calculate the time when the super moon appears?

No matter how many times the super moon appears in a year, or the time when the super moon appears each time, it can actually be calculated in advance. As we all know, 27.32 days is the period of the moon's revolution, but the average period of the first lunar month is 29.35 days. The time difference between these two periods causes the moon to need about 2 more days to return to the new moon (27.3*( 1+27.3/365)=29.4).

When we calculate from the calendar, we will find that 15 perigee full moon is actually very close to1April bright. In other words, it is equivalent to the super moon appearing every 4 13 days. However, because the time obtained by this calculation method is similar to that of the month before and after, the full moons appearing in these periods are gradually called super moons by many people.

The appearance of the super moon has a strong periodicity, mainly because the orbit of the moon and the orbit of the earth will not change fundamentally even in the time scale of hundreds of years. Therefore, the phenomena such as eclipses and eclipses that everyone pays special attention to are as regular as the super moon.