In 2011,astronomers announced that our galaxy is likely teeming with free-floating planets. In fact, these lonely worlds, and which sit quietly in the darkness of space without any companion planets or even a host sun,might outnumber stars in our Milky Way galaxy. The surprising discovery begged the question: Where did these objects approach from? Are they planets that were ejected from solar systems, or are they actually light-weight stars called brown dwarfs that formed alone in space like stars?
Source: phys.org