Hi EP,

Amateurs are those like me who do this in their own time, with their own money for the enjoyment and excitement of discovery and a great feeling of accomplishment. Professionals are the same except they get paid for it and generally rely on other peoples equipment - including amateur equipment :-)

Yes, statistically it is likely that a small object will hit us (and they do on a regular basis) though again your assessment of what amateur's can detect is incorrect. My system (35cm) is capable of and has detected objects as small as 25m more than days away from earth orbit - of course it depends on the albedo of the target. Yes, our equipment and techniques have a low probability of discovering them but if we are talking a returning object with perturbed orbit we should know the region of sky and a time!

With the number of professional surveys in operation in the Northern Hemisphere, amateurs with small scopes are being encouraged to undertake other work lest they 'taint' the pool with low precsion astrometry. In the Southern Hemisphere it is a different story and there is still some reliance on amateurs to do followup work on new discoveries.

SW3 - OK so how big are all those fragments? How many are likely to have survived this past perihelion passage and how many will in fact survive the next 2? Lets face it, SW3 is not the first and won't be the last Comet to completely fragment - nearly all our meteor storms can be traced back to a cometary path. Of course this is not to say that a couple of large pieces won't survive - but we will be watching :-)

There are, of course, new and more powerful surveys coming on line all the time. Panstarrs has, what looks like, wonderful credentials. I agree - amateurs are not the future for this work - but they will always have a part to play. Anyone remember 2004 AS1? Google it.