Earth's center of mass is not a fixed point. According to NASA scientists, it constantly moves, shifting by a few millimeters as enormous amounts of water, ice, and even air migrate around the planet with the seasons.
To measure these small swings, the researchers turned to laser-ranging, a technique that allows them to track the center of mass with greater precision than before. The new method captures the subtle seasonal movements that are easy to miss.
The measurements provide a clearer picture of how Earth's mass is distributed and how it changes over time. By monitoring these tiny shifts, scientists can better understand the dynamic processes that move material across the planet's surface.