Who knows how far the sun is from us?

The distance from the sun to the earth 1976 is determined by the International Astronomical Union as 149597870 km, which is used as the astronomical unit for measuring the distance.

How to measure? 17 16, Harley (a great comet named after him) proposed a method to measure the distance between the sun and the earth by observing the transit of venus at different locations. Transit of venus takes two transits as a group, with an interval of 8 years, but the interval between the two groups exceeds 100 years. China astronomers (well, fortune tellers, not astronomers) discovered the 8-year Venus cycle more than 2,200 years ago. The Western Han Dynasty's "Five Stars" wrote: "Five out, it is already eight years old, and the re-camp room leaves the east in the morning." In other words, the five rendezvous periods of Venus will wait until eight years, that is, Venus will appear in the same constellation at the same time eight years ago and eight years later.