rare! This year's "Fifteen Moons seventeen rounds"

On February 15, the Lantern Festival will usher in the Year of the Tiger. Surprisingly, the Lantern Moon of the Year of the Tiger is not "fifteen circles" or "sixteen circles", but "seventeen circles", and the roundest moment appears at 0:56 on February 17.

Lin Yuan, a member of the Chinese Astronomical Society and an expert in astronomy science in Tianjin, introduced that every time the moon runs between the earth and the sun at the beginning of the lunar calendar, the hemisphere illuminated by the sun carries the earth, we can't see the moon, called "new moon", also called "Shuo"; around the fifteenth day of the lunar calendar, the bright side of the moon is all facing the earth, and we can see the round moon, called "full moon", also called "looking". The length of time interval from "Shuo" to "Shuo", or from "Wang" to "Wang", is called a "Synodic Month", with an average of 29.53059 days.

Also on the first day of the lunar calendar, "Synod" may occur in the early morning, or in the morning, afternoon, or evening, and each "synodic month" itself has its own lengths and shorts. In this way, the "look" of the fullest moment of the moon can occur at the earliest on the night of the fourteenth day of the lunar calendar, and at the latest on the morning of the seventeenth day of the lunar calendar. However, because "Shuo" must be on the first day of each month of the lunar calendar, after "Shuo" on average, it takes another 14 days, 18 hours and 22 minutes to be "looking", so the "hope" of the fullest moment of the moon appears on the fifteenth and sixteenth days of the lunar calendar.

Statistics found that the most frequent occurrence of "full moon" is the sixteenth lunar calendar, followed by the fifteenth lunar calendar, the third is the seventeenth lunar calendar, and the least is the fourteenth lunar calendar.

"It is relatively rare for a 'fifteenth moon and seventeenth circle' like this year's Lantern Festival, the last time it appeared was on February 26, 2013 (the seventeenth day of the first month), and the next time it will reappear on March 1, 2029 (the seventeenth day of the first month). But no matter when it is round, the moon that people can see with the naked eye is basically no difference, it is the same flower good full moon, which will not affect people's appreciation of the moon on the night of the Lantern Festival. Lin Said.

When is the best night of the Lantern Festival? Two hours after sunset is a good time to admire the moon. "One is that the moon at this time looks particularly large; the second is that the moon is beautiful silvery-white and pleasing to the eye; and the third is that the moon's horizon height is low, which is suitable for taking beautiful photos of 'continuous moon with landscapes'." Lin Said that over time, the moon traveled to the sky due south in the middle of the night. At this time, the height of the moon's horizon reached the highest level in the whole night, and everything was silent, and the "Haoyue Top Sky Illumination" also had a different taste.

Source: Xinhua News Agency (Zhou Runjian)

Editor-in-charge: Wang Yuanfang

Editor: Zhang Yongqun