Hi Guys!  My answer is 'Uncle Bud inventing the "machine' ".  It's because if Uncle Bud hadn't created the machine, the aliens wouldn't be after the people on the ship.  My reason for believing that is because the aliens didn't go after The General or Jack's Mom, they weren't with the special item.  i'm not blaming Uncle Bud for making the contraption, how was he supposed to know that aliens would be after his machine?  I think that he made it so that he could use it to get to his brother, Jack's dad, who I think is the one human on "Skreepia".  I gotta go feed Wibur his afternoon snack now, so bye!