Scientists who study how our solar system formed have been hard pressed to explain the presence of extremely unusual chemical isotopes found in ancient meteoroids orbiting the Earth. The isotopes are short-lived and had to have been formed no earlier than the creation of the solar system, some five billion years ago. Yet these elements cannot be produced by a star as massive as our Sun under normal circumstances. So it has long been assumed that those isotopes were left there by a powerful, nearby star explosion. Now, scientists using the Chandra X-ray Observatory to look at young stars in the Orion Nebula have uncovered important clues about how those chemical isotopes got into our solar system. These young stars in Orion behave much as our own Sun would have at the same age. The scientists found that huge solar flares in young stars are more common than previously believed. So solar flare-ups from our young Sun could account for the presence of the isotopes.