A star passing close enough to the solar system can do considerable damage, including *ejecting entire planets into interstellar space*. Weird thing is, one of the planets most vulnerable to this is NOT the one you'd think.

Could the Solar System Lose a Planet to a Passing Star?

Close stellar encounters could change the structure of our planetary system, potentially dooming Earth or other worlds to oblivion

Scientific American (www.scientificamerican.com)