- Jack McDevitt
The history of the sun that we grew up with was fairly dull, as we all know. Four and a half billion years ago, it was nothing more than a cloud of leftover dust and atoms from an earlier set of stars. Those stars collapsed and exploded into dust and debris. A cloud formed and gradually the particles were drawn together and our sun was born. A million or so years later, we would have begun to see asteroids. And in another million, we might have become aware that planets were forming. And voila! Here we are.
If award-winning Rebecca Boyle has it right in the June issue of The Scientific American, that’s not quite the way it happened. The current evidence provides a more intriguing story. When the sun formed, it was part of a cloud of hundreds or possibly thousands of stars. Dust circled not one star, but all of them. Asteroids would have been forming everywhere, not just around the Sun. And within another million years, the first planets would have been forming. During the process they would have exchanged, or simply made off with, planets that had been orbiting other stars.
Gradually the stars spread out through the vacuum. They’re well into the galaxy now, but we may have found one of them. And with modern capability, we should be able to locate a substantial number of the Sun’s one-time siblings.
The consensus seems to be that the Sun would have been between 38 million and 120 million years old when the Earth formed. But who knows? In any case anyone looking for a plotline that has probably never been used might consider the possibility that Earth came together around a different sun than the one we have now. And maybe someone unexpected has been looking for us.