Martian opposition refers to the movement of Mars behind the earth, the earth is in the middle, forming a straight line with the three celestial bodies of the sun. Mars is around the opposition day, closest to the earth, and its apparent diameter and brightness also reach the extreme value. It is the best time to observe Mars, and it will happen every 780 days. Just today (16th), Mars is on the opposition to the sun again.
This year, the Martian opposition is just a "small opposition". According to popular science experts from the Beijing Planetarium, there is a difference between a "big opposition" and a "small opposition" on Mars' opposition to the Sun. This is because the orbit of Mars is a relatively flat ellipse. Mars is about 50 million kilometers away from the Earth's orbit at the perihelion point, while the arihelion point is 100 million kilometers away from the Earth's orbit. Therefore, there are also big differences in the observation effects of Mars' opposition to the perihelion and the arihelion. In recent times, I have been "small rushing" in daily life.
In addition, the date of Mars' opposition day does not necessarily coincide with the date that Mars opposition day is the closest date to Earth. This is due to the relatively large eccentricity of the Mars orbital orbit. The closest time to Mars is January 12, which is almost the same as the opposition day. There is no difference for observation. The month before and after the opposition day is a good time to observe Mars.
