Why an edge?
While theorists cannot say why there might be such an abrupt end to the solar system, they are beginning to look into the question, Bernstein told SPACE.com. It could be that the original solar system was simply not any bigger. Or perhaps a passing star, long ago, stripped away the debris that was orbiting the Sun beyond Pluto. David Jewitt of the University of Hawaii, who co-discovered the first KBO, thinks there will be another Pluto or two found in the next few years. Other scientists agree that this is likely, and expect the potential object or objects to be farther out than Pluto. Bernstein said that because the new study looked at only six patches of sky, the possibility of another Pluto can’t be ruled out. But he suspects that any such objects would still be within 50 AU. Others scientists have kept alive the possibility that a large 10th planet might lurk well beyond this range, though no conclusive proof of this has ever been found. If there was a large planet that had long ag
