Just tonight, look up!

The first "dog eating the moon" this year will appear on the 5th, which is a penumbral lunar eclipse

The first lunar eclipse of this year will take place on the 5th of this month. It is a penumbral lunar eclipse. At that time, the "face" of the moon will change from bright to dark and then from dark to bright. The whole process can be seen in my country. Astronomical science experts said that this is a penumbral lunar eclipse in which the moon enters the earth's penumbra relatively "deeply", and it almost becomes a partial lunar eclipse. The public who are interested can try to observe it.

How a lunar eclipse occurs.

Xiu Lipeng, a member of the Chinese Astronomical Society and an expert in astronomy popularization, introduced that a lunar eclipse is an astronomical phenomenon that occurs when the sun, the earth, and the moon are exactly or almost in the same straight line. Since the earth is between the sun and the moon, the earth's shadow will be divided into two parts under the sunlight. One part is the area where the sunlight is completely blocked by the earth, which is called the "umbra"; the other part is the area where part of the sunlight is blocked by the earth, and there is still a part that can be illuminated, which is called the "penumbra". When the moon enters the earth's umbra, a partial lunar eclipse or a total lunar eclipse will occur; if it only enters the earth's penumbra, a penumbral lunar eclipse will occur. However, during a partial lunar eclipse or a total lunar eclipse, the moon will also pass through the earth's penumbra, so it will also experience a penumbral lunar eclipse.

Schematic diagram of this penumbral lunar eclipse.

Astronomical forecasts show that this penumbral eclipse began at 23:12 Beijing time on the 5th, reached its peak at 01:23 on the 6th, and ended at 03:34. The entire process lasted more than four hours, with a maximum eclipse magnitude of 0.989. The eclipse magnitude represents the degree to which the moon enters the earth's penumbra, that is, 98.9% of the moon's diameter enters the earth's penumbra.

This is the moon photographed in Beijing on the night of November 28, 2012. Top: The moon at the beginning of the penumbral lunar eclipse at 20:13; Bottom: The moon at 22:02. Although the moonlight is dim, the layers of the moon's surface have increased. Photo by Xinhua News Agency reporter He Junchang

Xiu Lipeng said that a lunar eclipse must occur during the "full moon" phase, when the moon is in the full moon phase, which usually occurs on a day between the 14th and 17th of the lunar calendar. When a penumbral lunar eclipse occurs, the moon looks the same as a full moon, except that the brightness decreases, making the moon slightly darker. The difference is not easy to distinguish with the naked eye, but the change can be seen through photography. Although the viewing quality of a penumbral lunar eclipse is far less than that of a partial lunar eclipse or a total lunar eclipse, this penumbral lunar eclipse is somewhat unusual because the moon almost completely enters the Earth's penumbra, which means that although it does not touch the Earth's umbra, it is very close to the umbra, and such a penumbral lunar eclipse is relatively easy to detect with the naked eye.

This is a collage of photos taken in Beijing in the early morning of January 1, 2010, from the beginning to the maximum of the partial lunar eclipse (from left to right). Photo by Xinhua News Agency reporter Gong Lei

In a year, there may be up to three lunar eclipses, and at least none. This year, there will be two lunar eclipses. The next one will be on October 29th, which is a partial lunar eclipse, but the maximum eclipse magnitude is only 0.122, which is almost a penumbral lunar eclipse. Therefore, these two lunar eclipses this year are still very interesting.

This is the Eta Aquarid meteor shower taken by Chongqing astronomical photography enthusiast Dai Jianfeng in Hongyuan, Sichuan on May 7, 2022. (Photo provided by the author)

"Friends who plan to observe the penumbral lunar eclipse can also pay attention to the Eta Aquarids meteor shower, which has the 'bloodline' of Halley's Comet. The meteor shower will reach its peak on the 6th. Although a full moon almost makes this meteor shower 'vanish into thin air', it does not rule out the possibility that super bright fireballs 'stand out' under the bright moonlight." Xiu Lipeng reminded.

Planning: Liu Xinhui Reporter: Zhou Runjian Poster production: Hu Yanzhu Editors: Zhu Shun, Li Huan Xinhua News Agency Domestic Department and Xinhua News Agency Tianjin Branch jointly produced by Starry Sky Studio