Earth’s center of mass shifts back and forth each year as seasonal water redistribution changes where mass sits on and around the planet. NASA scientists report that enough water moves due to processes such as snow and monsoons, and through exchanges with oceans, to shift the center of mass by fractions of an inch relative to Earth’s geometric center.
The shifts are tracked because Earth’s center of mass is used as a key reference for measurements and services, including satellite navigation and elevation-related calculations. Both outlets describe the same general finding: seasonal cycles produce measurable oscillations in the center-of-mass position.
While the coverage aligns on the main result and its importance, the wording differs. NASA emphasizes that the changes are tied to the movement of water and that tracking these oscillations helps maintain accuracy for navigation and elevation measurements. Phys.org similarly highlights annual drivers—snow, monsoons, and ocean-related changes—underlining the role of multiple water systems. Neither outlet describes a change in Earth’s overall mass or a permanent relocation of the center.
