"Mars opposition" is happening today! Don't miss the best time to observe "Mars".

It's a good time to observe Mars. Astronomy experts say that Mars will reach opposition on January 16. The month before and after opposition is a good time to observe Mars. If the weather is fine, interested people can try to find this slightly reddish planet.

01 What is “ Mars opposition ”?

Mars is the first planet outside the Earth's orbit. It was called "Yinghuo" in ancient my country, and was named after the mythological god of war "Mars" in the West.

When the geocentric ecliptic longitude of Mars differs from that of the Sun by 180 degrees, that is, when Mars, the Earth, and the Sun are arranged in a nearly straight line, it is called Mars opposition. Opposition is a phenomenon that only occurs in the extraterrestrial planets (Mars, Jupiter, Saturn, Uranus, and Neptune), while the intraterrestrial planets (Venus and Mercury) do not have opposition. Before and after the opposition, the extraterrestrial planets are closest to the Earth, have the largest apparent diameter, and are the brightest, which is an excellent time to observe them.

02 The difference between “ big clash ” and “ small clash ”

According to Lai Dihui, a member of the Chinese Astronomical Society and director of the Tianjin Astronomical Society, Mars opposition occurs approximately every 26 months. Each time Mars opposition occurs, the distance between Mars and the Earth is different, which causes Mars to appear different in brightness and size, so there are "great opposition" and "minor opposition" of Mars. When the Earth is at aphelion and Mars is near perihelion, the distance between the Earth and Mars is smaller, which is the so-called "great opposition".

Mars (collage) photographed in Luohu, Shenzhen, Guangdong in July and September 2018. (Photo by Huang Yongxiong)

On average, a "Mars opposition" occurs every 15 to 17 years. The last "Mars opposition" occurred on July 27, 2018, when the brightness of Mars reached -2.8, exceeding that of Jupiter at the time. The next "Mars opposition" will occur in September 2035.

This opposition of Mars is a "minor opposition". During the opposition, Mars is located in Gemini, with a brightness of -1.5. After dark, Mars rises from the horizon in the northeast, and is located in the south sky at midnight, with a high altitude, making it easy to observe .

03 The fantasy of Earth’s “neighbors” becomes reality

Mars is not only a close neighbor of the Earth, but also the planet in the solar system that is most similar to the Earth. From ancient times to the present, people have had infinite imagination about this planet.

Human exploration of Mars began more than 60 years ago, and dozens of Mars exploration missions have been carried out around the world to date.

The medium-resolution camera of the Tianwen-1 mission orbiter carried out 284 orbits of remote sensing imaging over a period of 8 months from November 2021 to July 2022, achieving global coverage of the Martian surface. The ground application system processed the 14,757 image data obtained to obtain a global color image of Mars. The scientific research team identified a large number of geographical entities near the landing site through high-resolution images of Mars. According to relevant rules, the International Astronomical Union named 22 of these geographical entities after historical and cultural villages and towns in China with a population of less than 100,000. The Chinese logo will be permanently engraved on the land of Mars.

Since the successful implementation of the Mars exploration by the Tianwen-1 mission, China's Mars exploration and deep space exploration have continued to deepen. In the future, Tianwen-2, Tianwen-3, and Tianwen-4 will also be launched one after another to bring our "greetings" to Mars, Jupiter and other planets, promoting the continuous deepening of human understanding of the solar system and the universe.

Comprehensive sources: Xinhua News Agency, National Space Administration official website, People's Daily, etc.