American Horse
AKA "Mustang"
Well, whatever you wish to call them, and no matter what their origin, if one were to come through our solar system, it would definately be a case of there goes the neighborhood.
From NASA: The discovery is based on a joint Japan-New Zealand survey that scanned the center of the Milky Way galaxy during 2006 and 2007, revealing evidence for up to 10 free-floating planets roughly the mass of Jupiter. The isolated orbs, also known as orphan planets, are difficult to spot, and had gone undetected until now. The newfound planets are located at an average approximate distance of 10,000 to 20,000 light-years from Earth.
The bolded text clarifies the distance mentioned in the BLOG as 10 A.U.
SOURCE: Free-Floating Planets May be More Common Than Stars - NASA Jet Propulsion Laboratory