Millions of years ago, an asteroid is believed to have hit the Earth leading to the mass extinction of the dinosaurs. As catastrophic as that impact was to the Earth and life on the planet at the time, how bad would the impact have been if the asteroid had been another Earth-like planet.
Astronomers believe they have found evidence of just such an impact of two Earth-like planets in a distant solar system. Astronomers and researchers observed what they believed to be a young star called BD+20 307 using X-ray and other observation methods.
The scientists found a ring of debris around the star that holds a million times more dust than what circles our sun now. Space.com reports that earlier this year scientist studying the star and its orbiting debris discovered what they believed to be a single, young star was actually a very old binary pair.
Before the discovery of the second star, the astronomers believed that the dust and debris was simply leftovers from the formation of planets around the young star. However, the scientists were forced to rethink their theory after the second star was discovered and subsequently the stars were found to be billions of years old.
With this discovery, the researchers began to wonder why so much debris was present. If left over from initial planetary formation around the star pair, the dust and debris would have swept up into new planets or pushed away by solar radiation.
The only theory that fits with the discovery according to the scientist is that two orbiting planets -- about the size of Earth -- collided with massively catastrophic results. The collision would have happened sometime in the last few hundred thousand years.
Benjamin Zuckerman, professor of physics and astronomy at UCLA says, "It's as if Earth and Venus collided. Astronomers have never seen anything like this before. Apparently, major catastrophic collisions can take place in a fully mature planetary system."
Tennessee State University astronomer Gregory Henry said, "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."
Other researchers on the project pose the important question: How do planetary orbits in mature planetary systems destabilize to the point of a catastrophic collision? The other major question according to astronomer Francis Fekel from TSU is could such a collision happen in our solar system.
Part of the answer to the question of could massive collisions happen in our own solar system is yes. Scientists point out that in addition to the asteroid believed to have caused the extinction of the dinosaurs, a massive collision with the Earth is believed to have created the moon.
Henry refers to computer models that have shown that a collision between Earth and a Mars-sized object is believed to have ejected the material from Earth that formed our moon. Henry also points out that there is a small potential of a collision of Mercury with Earth of Venus in the next billion years.
