Mercury's magnetic field is about 100 times weaker than that of the Earth - a curiosity that scientists have been trying to make sense of for years.

Recent observations of Mercury's rotation suggest that the planet has a partially molten core, and scientists at the University of Illinois and Case Western Reserve University developed laboratory experiments to model what might be happening beneath the surface.

An earthquake is a sudden release of stress that has built up along a fault line, where rock faces push against each other. If that stress could be released over a longer period of time—with a series of smaller quakes—the result might be less catastrophic.

Engineers have known for 40 years that injecting fluids deep into wells can accidentally trigger mini—quakes by lubricating “sticky” rock faces. Since that time, there have been numerous proposals to pump fluids into stressed fault lines.