The repeated waxing and waning of the moon that people see on the earth is called the moon phase, which is the "appearance" of the moon. Its change cycle averages 29.53 days. Common moon phase names include new moon, crescent moon, and first quarter. Moon, waxing gibbous moon, waning gibbous moon, waning gibbous moon, waning gibbous moon, etc.
Among them, during the first quarter moon, people can see half of the bright moon rising in the sky after the sun sets in the west. At this time, the western half of the moon is illuminated by the sun; during the waning moon, people can see half of the bright moon rising in the east, usually at midnight. , when the eastern half of the moon is illuminated by the sun.
"The first quarter moon must appear in the first half of the lunar month, with the moon facing west; the waning moon must appear in the second half of the lunar month, with the moon facing east." Yang Jing, member of the Chinese Astronomical Society and director of the Tianjin Astronomical Society explain.
In 2024, there will be 12 first quarter moons and 13 waning moons. The first quarter moon on June 14 is the farthest from the Earth among the 12 first quarter moons this year.
Yang Jing said that the moonās orbit around the earth is an ellipse. During the operation, it is sometimes far away from the earth and sometimes close. The farthest time is more than 400,000 kilometers, and the closest time is less than 360,000 kilometers. The difference between the two is about 5 Thousands of kilometers. The so-called annual minimum first quarter moon refers to when the moon phase is first quarter and the moon moves near the apogee at the same time. At this time, the apparent diameter of the first quarter moon is the smallest. Specifically, the first quarter moon at 13:18 on June 14 is only more than 8 hours different from the moon passing apogee at 21:35 that day.
The interval between the first quarter moon and the last quarter moon is about 14 to 15 days, while the interval between the moon's perigee and apogee is about 13 to 14 days. The annual minimum first quarter moon and the annual maximum last quarter moon are usually in the same lunar month or adjacent Two lunar months appear. The largest waning moon of the year will occur at 5:53 on June 29.
"For the general public, whether it is the annual minimum first quarter moon or the maximum waning moon, to the naked eye, there is little difference from the quarter moon in other months. Interested members of the public can try to compare the maximum and maximum waning moons of this month. It would be interesting to take photos of the smallest crescent moon using the same shooting parameters and then stitch them together for comparison," Yang Jing said.
Source: Xinhua News Agency
