It seems that some people are willing to change their ideas in the face of evidence, specifically Comet Hale-Bopp’s possession of much Argon gas (that concept’s a bit difficult to support if Hale-Bopp started 4.5 billion years ago and just continued) is causing some scientists to speculate that H-B was “started” relatively recently in the vacinity of Neptune, quote:
the discovery of a certain noble gas tells scientists that an object has spent most its life without heating above the temperature where that gas would steam off into space
In space, argon is solid only below about 35 degrees Kelvin [...]
This and the absence of Neon (melts at about 20degK) around the comet hints that H-B formed near Uranus or Neptune, where heating above 20degK but not 35degK would be more reasonable.
It’s good to see scientists doing more than simply toeing the line with their theories. (-: