What does the bluish color suggest?
We are very surprised by the bluish color. We normally classify Kuiper belt objects based on their orbit, making Antipholus part of the “cold classical main Kuiper belt” (which is quite a mouth full). But cold classicals are typically redder. Perhaps 2001 QW322 is a member of the “hot classical main Kuiper belt”, whose members are bluer, but at the low inclination end of the distribution of those objects. If this is the case, then it is even more difficult to understand how it could survive the “excitation” process. Generally however, the bluish color suggests an icy mantel, which could indicate some ancient collision.
