Sun Below Horizon

A "dark core" of a high-density object that cannot be seen by telescopes approaches the Earth-Moon system. It will not hit the earth, but it will affect the oceans, earth's crust and human society through gravitational disturbances. Chen Yan, a surveying and mapping engineer from Shiling County, started from an abnormal solar altitude angle and traced the line hammer offset records in an abandoned coal mine decades ago. Finally, he participated in the National Deep Well Gravity Observation Project and "heard" the sound before the arrival of a cosmic disaster 800 meters underground.