Hi Nick -

Since impact risk is best estimated by the record of actual impacts with the Earth, you have to ask yourself why this PR release was worded the way it was - what was the motive in doing this?

Since the number of impacts with the Earth remains the same, the only conclusion that could be drawn from their data is that for larger impacts, more impactors must have been cometary in nature, and not asteroidal.

The number of smaller impacts also remains the same, and while Sloan is a pretty good telescope, due to the simple restrictions of Earth based observation it is not capable of mapping smaller asteroids with any degree of completeness -

ah well -

EP