Its relatively thin crust rests on an 1,800-mile-thick layer of solid rock under such heat and pressure ... The ways seismic waves reflect from, bend (refract) around or cast shadows reveal this inner ...

For years, scientists have pondered the mysterious structures deep within the Earth. Research indicates that they are billions of years old. Could these be remnants of an ancient planet that once ...

Arguably the most fascinating moon in the Solar System is the Saturn satellite Titan, which has the only known body with liquid seas and rivers (of methane) on its surface. A new study suggests ...