pilot to pull it off. even then, the dot would probably be bigger or more intense than usual and could attract the attention of a radar operator somewhere. anderson, when people try to figure out beyond what we know that initial flight into all this conjecture how it could have happened, theories like this have to be considered, no matter how outlandish, simply because here we are a week and a half later and we just don't know. >> and these are certainly things that investigators from every country who's involved in this are certainly looking at and trying to play out the many steps of what it would entail. tom, appreciate it. i want to bring in john hansman a professor of aeronautics. also back with us is jim tilmon. professor hanson, about all the theories out there about what happened, at this point which seem most plausible to you? >> well, we've got to keep everything on the table but a couple days ago everybody rejected the catastrophic failure idea and now it's pack on the table and that's credible.