Earth's center of mass sounds like a fixed point, but it is not. As water, ice, and other material shift across the planet, the center of mass moves slightly. A new study has taken a closer look at just how much it drifts.
The researchers found that the drift is smaller than previous estimates indicated. That means Earth's center of mass is more stable than many scientists assumed, which is significant because precise measurements of the planet's shape, rotation, and gravitational field depend on knowing where that center is.
A more accurate picture of the center of mass also matters for practical applications like satellite navigation and monitoring changes in Earth's surface. The new result suggests some corrections used in these systems may be smaller than thought, though the full implications depend on the details of the model.