Researchers discovered a closely orbiting pair of supermassive black holes in Markarian 501 by tracking two jets of particles. The binary system could merge within 100 years and may produce detectable gravitational waves. Current evidence indicates that nearly every large galaxy contains a supermassive black hole at its center, with a mass ranging from millions [...]

A study suggests pigeons navigate using iron-rich immune cells in their livers that can respond to Earth’s magnetic field. The findings may solve a decades-old mystery about bird navigation and reveal a surprising new sensory role for the immune system. Pigeons are famous for their ability to travel long distances and still find their way [...]