Scientists studying particles of comet dust captured by the spacecraft Stardust reported a big surprise Monday. Findings from the mission are challenging assumptions about comets and how they formed.
Comets are described as clouds of ice, dust and gases, cruising the coldest fringes of the solar system. But scientists studying comet dust from the Stardust probe found minerals formed by intense heat, suggesting the minerals came from the neighborhood of the sun itself. That's the earliest discovery in what's expected to be decades of study.
The mission, designed to resolve questions about the origins of the solar system, has now added new questions to the list. How did hot minerals from the blistering core get to the frigid outer reaches? Or did the minerals come from other stars? And maybe comets aren't quite what we thought, if those icy bodies contain minerals forged by fire. The Stardust spacecraft returned to Earth two months ago with tiny particles from the comet Wild 2.