The Impacts of D/Shoemaker-Levy 9 and Bioastronomy

The impacts of comet D/Shoemaker-Levy 9 into Jupiter provided the first chance to actually observe the effects which may be important in causing mass extinctions. The widely predicted global deposition of dust, leading to the phenomena associated with 'nuclear winter', was readily observed, although Jupiter's internal heat source causes a different response deep in the atmosphere than occurs on Earth. Less widely anticipated, despite recognition that global wildfires occurred during the K-T event on Earth, was the fact that material ejected above the stratosphere fell back onto the stratosphere producing a major heat pulse over a scale of 104 km, by far the most easily and widely observed phenomenon during the impacts.