Various anomalous features of the solar system, such as the tilt of Jupiter could have resulted from this event. It also appears that this may not be a rare event; many free-floating 'orphan' planets may be out there. This has been confirmed by a recent discovery of a huge free-floating planet very close to our solar system, which is six times the mass of Jupiter. There are now many of these objects catalogued. You do wonder if some of our own planets in our solar system were free-floating once, and were caught up into the newly-formed solar system never to travel alone again.
The March of the Orphans
Free-floating planets are not a new idea, and have also contributed to much of the hype surrounding the infamous date; 21st of December, 2012. Nibiru or 'Planet X', first sprang in the emerging internet in 1995, with hordes of doom-mongers saying that an orphan exoplanet would have a cataclysmic collision with Earth. As we all know, this didn't happen - nor is it very likely. Though the website from which these claims originated would like to have you believing otherwise (the images of 'Planet X' are the most baffling), they are not the first, nor the most fascinating ideas about other objects that may be associated with our Sun. In fact, the history of these supposed missing planets probably spurred the search and discovery of a few of the larger objects in our solar system, and one of the current eight canonical planets.
The Giants and the Dwarves
Dwarf planets became a better-known term after the demotion of Pluto in 2006 from the ninth planet in our solar system to one of several in the lesser pantheon of planets. Pluto's discovery was driven by the hypothesis of there being a ninth 'planet X' - though this term was coined well before the pseudo-scientific belief in a 'Nibiru'. In fact, another planet discovered by mathematical prediction - Neptune - aided in finding this tiny, icy world. Fluctuations in Neptune's orbit led to the search continuing even further out into the sticks of the solar system. This next planet was believed to be another gas giant, after all, the trend from Jupiter outwards did not hint at anything other than the status quo of the outer solar system. This made Pluto serve only to be a sad disappointment for these predictions.The planet's estimated size shrank ever downwards over the resulting years, and it's bizarre orbit (where it actually becomes closer to the sun than Neptune for 20 years of its 248-year orbit) led to this object finally being demoted. Although the biggest object in the Kuiper Belt, it appears to be a small component of a large body of objects that circulate the sun in this vicinity.
Dwarf planets also exist (or have been proposed) much closer to home. Ceres, a large dwarf planet in the asteroid belt between Mars and Jupiter was also classified as a planet for a time, although it shares its orbit with many other asteroids, making up only a third of the mass of the belt. Again, Ceres was discovered by the belief that there would be a planet in this location. However, the final discovery of objects after postulating their existence does not always occur (see above). Vulcan was proposed to be between Mercury and the sun, with an active search for Vulcan continuing well into the 20th Century. Small objects are known to orbit closer to the sun than Mercury, but nothing on the scale of a planet 'zero'. It would pretty hard to identify anything in this vicinity due to the Sun's glare. You would hope that modern planet-hunting techniques have eliminated any hope of their being a scorched rock on the scale of anything planetary. Even the claims that a 'counter-Earth' exists have been completely debunked.
No doubt there will continue to be objects on the same scale as Jupiter found outside of our solar system - this seems certain. However, the search for any other planets which are closer to home is probably never going to be productive. What lies outside our solar system that isn't on the scale of a star (or producing light - more on this soon) now provides a new focus for planet hunting. However, if we go back in time, maybe there were other planets that have now gone off to pastures new, wandering the galaxy looking for a new home.
