FYI -- And we thought that Earth's orbits were getting full of space junk... I can envision 'Star Trek'-like starships ending up like windshield-splatted bugs in picoseconds... https://motherboard.vice.com/en_us/article/mbaw5y/rogue-planets-are-roaming-... http://www.nature.com/nature/journal/vaop/ncurrent/full/nature23276.html Planet formation theories predict that some planets may be ejected from their parent systems as result of dynamical interactions and other processes. Unbound planets can also be formed through gravitational collapse, in a way similar to that in which stars form. A handful of free-floating planetary-mass objects have been discovered by infrared surveys of young stellar clusters and star-forming regions as well as wide-field surveys, but these studies are incomplete for objects below five Jupiter masses.