Satellites have managed to detect faint electromagnetic signals generated by ocean tides, suggesting that space-born sensors could be used to obtain insights into the motion of other liquid masses on Earth, including magma below the planet's surface.
The observations were made by the European Space Agency's (ESA) Swarm constellation, which consists of three satellites circling the planet in low Earth orbit at altitudes between 287 and 318 miles (462 to 511 kilometers).
