Close? As in 0.69AU, more than half the distance to the Sun? However, it's true that these objects that spend most of their long orbits outside of Neptune's o

Close? As in 0.69AU, more than half the distance to the Sun? However, it's true that these objects that spend most of their long orbits outside of Neptune's orbit are going to be hard to detect until they enter the near solar system. Luckily, most of these objects are also inclined well away from the ecliptic, and so their probability of an interaction is low. The closest this object could ever get to Earth on its orbit is 0.36AU.