1.   As the black spots created by cometary impacts faded, puzzling dark rings were sighted around some of them, for which astronomers could offer no good explanations.

2.   For one thing, the cometary impacts will be hidden behind Jupiter.

3.   If the cometary impacts on Jupiter cause only shallow disruptions of its atmosphere, the huge blotches the impacts have left may fade and disappear fairly soon.

4.   One of the questions raised by the cometary impacts on Jupiter is why the impact spots looked black.

5.   Shoemaker remarked that the episode gave astronomers their first chance to calculate the time and circumstances of a cometary impact on a planet.

6.   The cometary impacts may have set in motion the same kind of seismic waves generated by terrestrial earthquakes, waves capable of traveling all the way through a planet.

7.   The cometary impacts have all occurred on the back side of Jupiter, not directly visible from Earth.