Modern science tells us that Jupiter is second only to the sun in size and weight, and it orbits the sun for 12 years. The ancients found that Jupiter has a great influence on the earth, and the zodiac came from it, so Jupiter is also called the "old star".
The rendezvous period of Saturn and Jupiter is 20 years, that of Saturn, Jupiter and Mercury is 60 years, and that of the nine planets in the solar system is 180 years. This coincides with the time division of Feng Shui, which is one yuan for 60 years and three yuan 180 years.
When planets meet, it will have many influences on the earth, such as disturbing the earth's magnetic field and causing natural disasters. It can be seen that it is very reasonable for the ancients to calculate good and bad luck with the three yuan and nine fortunes of Feng Shui.