When Worlds Collide, LiterallyDo you remember that one episode of Mythbusters, when they wanted to find out what would happen if two Earth-sized planets smashed into each other, so they called in some favors and got a solar system with two Earth-sized planets, smashed them together, then showed the awesome high-speed camera footage of it over and over? Me neither. But we can pretend it really happened, because scientists found a solar system littered with the remains of two shattered planets. Could it happen here?Astronomers were checking out a star very similar to ours located about 300 light years away, in the constellation Ares, and they noticed it was surrounded by a lot of dust. Way more dust than is in our solar system. They figured it must be a young star, and the dust just hadn't been blown away or formed into planets yet. But then someone took a closer look and realized two things: it was actually a binary star, and the system was actually very very old. All that dust would get blown away pretty quickly unless it just appeared recently. And the only way it could have appeared so recently in such an old solar system is if two really large chunks of rock (aka planets) smashed into each other. Scientists figure it happened within the last 100,000 years or so. The awe-inspiring scale of such planetary demolition inspired one of the scientists, Tennessee State University astronomer Gregory Henry, to wax dramatic:
If any life was present on either planet, the massive collision would have wiped out everything in a matter of minutes — the ultimate extinction event. A massive disk of infrared-emitting dust circling the star provides silent testimony to this sad fate.
No one is sure what might cause planets' orbits to destabilize so drastically, but statistical projections show that there is a small chance of Mercury or Venus hitting Earth at some point in the next few million years. Which would probably look exceptionally cool for the first few minutes. Somewhat overshadowed by all the smashing planets is the fact that this solar system is the first scientists have found in which Earth-like planets orbited a binary star. Artist's conception by: Lynette R. Cook via Science Daily. Two Planets Suffer Violent Collision. [Science Daily]