The Important Contribution of Julius Pei Piazi

Ceres rushed to the sun in 2004 1 month 10, and the brightness reached 6.8. The best time to observe ceres is around the sun. The attached table lists the right meridian, right latitude, angular distance from the sun and visual magnitude of Ceres before and after the sun. Ceres lingered in Gemini before and after the solar eclipse, while asteroid 6 just ran in Canis minor and Gemini during this period (asteroid 6 eclipsed the sun on June+1October 65438+1October 065438+1October 0).

Compared with other planets, Ceres is very small, with a diameter of about 950 kilometers and a mass of about 1/85 of that of the moon. A few years after it was discovered, scientists found some smaller celestial bodies between Mars and Jupiter, some of which were only tens of kilometers in diameter.

Because these celestial bodies are very small, in the early19th century, the British astronomer Herschel suggested calling them asteroids. This suggestion was quickly adopted, and Ceres lost its status as a planet. The area between Mars and Jupiter is now called the asteroid belt. For nearly two centuries, Ceres has been regarded as the largest asteroid, accounting for about 1/4 of the mass of all celestial bodies in this region.

Ceres is generally spherical and very round compared with other asteroids, which is the result of its gravity. Its average distance from the sun is about 420 million kilometers, and period of revolution is 4.6 Earth years. Computer simulation shows that the density of ceres' surface layer is less than its interior.

Infrared image of ceres

Ceres has been sitting on the "cold bench" for a long time because of its ugly appearance. But scientists have recently discovered that this asteroid is very similar to the earth in many ways. 267 images taken by Hubble Space Telescope for Ceres show that Ceres is almost spherical, and its substance is unevenly distributed in it. The computer model shows that Ceres is divided into different layers: dense matter is in the core and lighter matter is near the surface. It may include a surface rich in ice water and a rock core. A report in the United States says that if 25% of Ceres' surface layer is made up of water, then its fresh water content is more than that of the earth. Not long ago, it won the title of "dwarf planet" on an equal footing with Pluto, which doubled people's interest in it. According to NASA, a Dawn detector will be launched to detect Ceres and Vesta, because they are the largest protoplanets in the solar system and have been intact since their formation. Through their exploration, scientists will discover all kinds of information from this unknown world, including mountains, canyons, craters, lava flows, polar ice sheets and possible ancient river beds and valleys, which will enable them to understand the early environment of the solar system and the whole formation process of the solar system. It is estimated that Dawn will take off on June 20th, 2007, arrive at Vesta at 201,and go to Vesta at 201on May.