On Saturday an extraordinary event will occur that will illustrate the vulnerability of humankind and its fragile tenure on planet Earth.
Comet Shoemaker-Levy 9 will crash in Jupiter. A similar collision into Earth would perhaps eliminate human life leaving the planet to another phase of evolution, much as what happened when the dinosaurs became extinct 60 million years ago.
The comet has already broken into 20 pieces and astronomers are calculating with increasing precision where and when the bits will strike. Imagine if it were heading for Earth.
Perhaps the significance of the event will be that it leads to that speculation. Previously such speculation was fairly idle. It was mostly confined to professional astronomers with the occasional foray into the popular media. Human speculation about a comet, asteroid or giant meteor colliding with Earth has been around for a long time. The pot-marked moon tells us that such a thing might be possible and various crater remnants on Earth show that our atmosphere is no guaranteed protection. Because of Comer Shoemaker-Levy, the speculation will be less idle, more widespread and perhaps more constructive.
It is exciting that science has been able to observe the comet and predict the event. It shows that science is capable of predicting whether a comet is to hit Earth, though whether a collision with a small asteroid or meteor is predictable is another matter. It may be all over before we know it.
Perhaps the event on Jupiter will put some of our earthly concerns into perspective.
It may also garner those in power to see greater value in astronomy – that it is important for humankind to understand its place in the solar system. The Jupiter event shows that a cataclysmic collision with Earth is not completely fanciful and that if anything at all could be done to avoid it, it would best be done co-operatively. We are together on this planet. Moreover, greater international co-operation in science is more likely to generate more confident calls of all clear.
Even without the threat of a collision, greater co-operation would be beneficial, but who knows, one day our continued existence might depend on it.