A Little Bang

Just as most cosmologists say the universe was birthed in a Big Bang, a new computer model supports the theory that our solar system started in a Little Bang.

The new model is the first to present a plausible development scenario. It suggests a nearby star exploded in a supernova. The shock waves of that blast condensed parts of a huge cloud of gas and dust. One of those parts became the Sun. A key piece of the case for this theory is the presence of a rare isotope of iron in meteorites and asteroids. That isotope is only created in the cores of huge stars. When such a star goes supernova, the iron is thrown out into space. So, the shock waves from the explosion triggered the formation of the Sun, and the rare iron isotope became part of the new solar system.