http://www.space.com/scienceastronom...ay_031215.html

The above link talks about what constitutes a planet. However one
interesting line they put in was:

"In contrast, there are observational hints of lone, wandering planets not
hosted by any star. "

What observational hints? I've never heard of this before. Has someone
observed a huge rock floating through interestellar space? I'm sure they
exist, but has someone seen one? Or how do they get an "observational hint"?

Yousuf Khan