Extra Giant Planet May Have Dwelled in Our Solar System

http://www.livescience.com/17110-extra-giant-planet-solar-system.html

Billions of years ago, it is possible that a giant planet might have inhabitied the solar system alongside Jupiter, Saturn, Neptune and Uranus.

This possibility has been discovered using computer models, showing how our solar system formed. They suggested the two planets onceused gravity to sling one another across space, only settling into their own orbits after billions of years.

"During more than 6,000 scattering phase, planetary scientist David Nesvorny at the Southwest Research Institute in Boulder, Colorado, found that a solar system that began with four giant planets only had a 2.5% chance of leading to the orbits presently seen now. These systems would be too violent in their youth to end up resembling ours, most likely resulting in systems that have less than four giants over time."

Instead, our solar system probably began with five giants, with a now lost world around the size of Uranus and Neptune. It was probably an "ice giant," just like them, Nesvorny explained.

When the solar system was around 600 million years old, there was a major period of instability that scattered giant planets and smaller worlds, researchers said. Eventually, a gravitational encounter would have flung the mystery planet to interstellar space around 4 billion years ago.

Many planets have been discovered in interstellar space, so such an ejection might be common.

Nesvorny says that this is just the beginning. "It will need quite a lot of work to see if there actually was a fifth planet. Iam not fully convinced myself."

As for me, Ithink that this is truly amazing and that the world should definitely be told about this if it turns out to be true.