On July 24th, Pluto will clash with the sun. Before and after the solar eclipse, Pluto is closest to Earth, with the largest apparent diameter and highest brightness, providing a good opportunity for humans to understand this dwarf planet. According to astronomical science experts, during this solar eclipse, Pluto's brightness is about 14.4 magnitude, which is too dark for ordinary binoculars or small astronomical telescopes to observe. Therefore, this celestial phenomenon is impossible for the vast majority of people to observe, and they can only take this opportunity to learn about Pluto. Pluto is not unfamiliar to people because it once ranked among the planets and was the ninth largest planet in the solar system, but was later "cleared" from the planetary ranks and downgraded to a dwarf planet. Despite being classified as a dwarf planet, it is still talked about by many astronomy enthusiasts today due to its dramatic history and unique orbit, and they don't forget to pay attention to where Pluto goes during its annual opposition. Pluto's opposition to the sun refers to an astronomical phenomenon in which Pluto orbits around the sun to roughly align with the Earth and the Sun, with the Earth located between the Sun and Pluto. Song Yuanyuan, a member of the Tianjin Astronomical Society and an expert in astronomical science popularization at the Tianjin Science and Technology Museum, said that Pluto is currently moving towards the aphelion (the farthest point from the sun), and the opposition to the sun is getting farther and darker every year. In 1989, Pluto passed its perihelion (the closest point to the Sun), and its brightness reached 13.7 magnitude during its opposition to the Sun that year. Afterwards, Pluto began to move towards the aphelion, and every year during its opposition to the sun, its distance became farther, so its brightness would decrease year by year. When reaching aphelion in 2114, even Pluto, which is in opposition to the sun, has a brightness of only 16th magnitude, making it difficult to see with a large aperture telescope. During this solar eclipse, experienced astronomy enthusiasts can use large aperture astronomical telescopes to challenge themselves and see if they can catch a glimpse of Pluto's true appearance in a light free environment Song Yuanyuan said. In the era of the 'Nine Great Planets', Pluto was the farthest and least massive planet from the Sun. In the eyes of scientists, Pluto has always been shrouded in mystery. At present, only the US New Horizons probe conducted some exploration during its flyby of Pluto in 2015, discovering mountains, ice fields, deep valleys, and sand dunes on Pluto. Song Yuanyuan introduced that although Pluto has exited the planetary stage, humanity's search for the "ninth planet" has never stopped. Many astronomers believe that the 'ninth planet' must be lurking somewhere in the solar system waiting for humans to discover it. Is there really a planet that "emerges" like this? Let's wait and see. (New Society)