Transit of venus is a very rare astronomical phenomenon because the orbital plane of Venus is tilted 3.4 degrees from the ecliptic of the Earth. The occurrence intervals are 105.5 years, 8 years,1210.5 years, 8 years ... It can be described as "eight years in pairs, a hundred years in fragrance". It is by seeing the parallax of the transit of venus process in different directions on the earth that the distance between the sun and the earth can be calculated by triangulation, and then the grand map of the whole solar system can be measured with this "astronomical unit" as the baseline.
Transit of venus/KLOC-The two major observation actions in the 0/8th century are Changhong's human epic. Astronomers all over the world collect data from their lives and loyalties, and our planet produces new wisdom. Lalande, a famous French mathematician who once selected the transit of venus observation point for the world, competed with many of his colleagues. With the method created by Harley and Delile, the observation data of 1 year 17 130 and 154 in 1769 are systematically summarized and calculated, and finally an unprecedented great conclusion is reached: the parallax of the sun is 8.5 arc seconds. Very close to the currently recognized 65438+496 million kilometers.
Since then, there has been a convenient and universal astronomical unit in the world. Humans not only have a panoramic view of the planetary neighbors of the entire solar system, but also look at the vast space, and since then, the great scientific era of international cooperation has begun.