SpaceMagnetic meteorites narrow down solar system’s birthdate Magnetic fields in 4-billion-year-old rocks suggest the dust and gas cloud that spawned the solar system had gone by 3.8 million years after the sun formed 51¶¯Âþ
SpaceCold case: The unsolved mystery of what lit Kepler's supernova In 1604, the last Milky Way supernova recorded by naked-eye observers brightened the night sky. Despite 400 years of study, we still don't know what lit the fuse 51¶¯Âþ