Yeh I saw that on Astronomy Pic of the Day recently. Really puts
a whole new difficulty on Interstellar space travel lol.. Not sure I'd
like to hit a Jupiter sized free floater out there. Apparently most of them are around the centre of the galaxy. Possibly
tossed out from their host stars.
I have Universe Simulator, and often wondered how often planets
to get tossed out in RL. Once, I sent a Jupiter sized planet cruising
past the Solar System a bit further out than the Oort Cloud, and it totally
distruped Earths Orbit.
A Passing Star totally destroyed the entire Solar System. Black holes
obviously have a similar effect. It's nice we've drifted away from
our original Stellar Cluster the sun was born in (if it was, probably
pretty likely).