Xinhua News Agency, Tianjin, April 3 (Reporter Zhou Runjian) What kind of sparks will be sparked when three different types of celestial bodies, planets, stars and moon, gather in the night sky?

The opportunity is here. On April 5, the brightest star in Mars and Gemini, Beihe San, will be accompanied by a crescent moon, and will stage a "Three Heroes". If the weather is sunny, interested public can try to observe.

The phenomenon of round and incomplete changes of the moon that people see on the earth is called the moon phase, that is, the "appearance" of the moon. Common moon phase names include the new moon, the upper crescent moon, the upper crescent moon, the full convex moon, the looking of the moon, the deficient convex moon, the lower crescent moon, the waning moon, the waning moon, etc.

Beihe 3 and Beihe 2 in Gemini, photographed on March 28, 2025 in Fengtai Garden, Fengtai District, Beijing. (Photo by Wang Junfeng)

"The upper crescent moon must appear in the first half of the lunar month, with the moon facing west; the lower crescent moon must appear in the second half of the lunar month, with the moon facing east." said Xiu Lipeng, a member of the Chinese Astronomical Society and an astronomical popular science expert.

As a large planet in the solar system, Mars is red, which was called "Yinghuo" in ancient my country. In the solar system, Mars is not only the closest neighbor of the earth, but also the planet most similar to the earth, so it has become the focus of human exploration. With the continuous advancement of aerospace technology and the continuous deepening of international cooperation, mankind is expected to transform Mars into the "second home" of mankind in the near future.

Xu Lipeng introduced that since this year, Mars has appeared in the southeast sky after sunset, and the horizon is getting higher and higher. Entering April, Mars is direct in Gemini, but its brightness has dropped from -1.5 at the beginning of the year to 0.5. Beihe San, also known as Gemini Beta, is the brightest star in Gemini.

Beihe 3 and Beihe 2 in Gemini, photographed on April 2, 2025 in Jiahe Village, Liulihe Town, Fangshan District, Beijing. (Photo by Wang Junfeng)

Because Gemini is a zodiac sign, this also means that the moon will run near it every month. On the evening of April 5, a crescent moon runs to the head of Gemini, accompanying Mars and Beihe.

"After sunset that day, these three different types of celestial bodies were always accompanied by close distance. A closer look will reveal that Mars and the moon are like the "two boys" in Gemini, each holding a toy, which is very interesting, especially around midnight, where the "two boys" will stand on the western horizon, and this interesting scene will appear more vivid." Xiu Lipeng said.