Molten droplets in meteorites help date Jupiter’s planetary birth

A recent study by researchers from Japan’s Nagoya University and the Italian National Institute for Astrophysics (INAF) has dated Jupiter’s formation to approximately 1.8 million years after the solar system began. This breakthrough was achieved by analyzing chondrules—tiny, 0.1-2 millimeter molten rock droplets found in meteorites. The study’s computer simulations showed that Jupiter’s growing gravity caused high-speed collisions between water-rich planetesimals, vaporizing water and producing steam explosions that shattered molten rock into these droplets. These chondrules later cooled and became part of asteroids that eventually fell to Earth as meteorites. The research not only explains the long-standing mystery of chondrule formation but also links it directly to the birth of Jupiter. By correlating the timing of planetesimal collisions in their models with the ages of chondrules found in meteorites, the team pinpointed Jupiter’s formation during its rapid gas accumulation phase. This method provides a novel way to