Seasonal changes redistribute enough water around Earth to shift the planet’s center of mass back and forth by fractions of an inch relative to its geometric center. NASA scientists are on the case, tracking the oscillations because Earth’s center of mass is a crucial reference point for satellite navigation and elevation measurements. A team, led
One of the major rivers of Europe, the Elbe flows more than 1,000 kilometers (600 miles) across the continent before reaching the North Sea. At its mouth, the low-lying landscape is continually reshaped by the rise and fall of the tides. These dynamic tidal flats are a boon to biodiversity while sometimes posing challenges for