The End of the World · How? · Comet (2/2)

On the opposite side stand opposite arguments.

The comets number millions of millions. Far more, including the parabolic majority, must cut the earth’s orbit than is known. Biela’s comes every seven years to a place where we visit in November. In 1819, in 1832, in 1861⁠—to name but three neighbours in time⁠—the tip of the tail grazed us. In 1832 especially we had the narrowest escape: with the Reform Bill just being voted⁠—extension of the suffrage, redistribution of seats, Weymouth reduced to two members, Old Sarum disfranchised altogether⁠—what a disaster it would have been! In 1770 the earth and the comet were at the same point during the same day; only a few hours divided them from impact. Thus Arago’s one in twenty-eight million is a dubious estimate. One in twenty-eight thousand may be quite as accurate⁠—quite as inaccurate. A disaster avoidable by finite chance alone is not of infinite unlikelihood. Time is boundless. There is time for this.

To end us, no need for a comet to cut our orbit. It might crash with Jupiter, restore him his lost light, make him a sun again; we should be lighted by two suns; human life, inadaptable to eternal day, would perish.

There is reason to believe⁠—if one wants to⁠—that long ago a great comet did strike the earth, sinking Atlantis, causing the Great Drift, ushering in the last ice age. A greater comet may in the future do far worse.

Many are far from rarified. Larger than the earth itself, they are solid and opaque, containing a central mass of rocks and stones and sand as wide as Russia, collision with which would be the catastrophe. Solid they must anyhow be; the gases spectroscopically seen in them would have long ago vanished off into space unless there were a substantial nucleus to hold them gravitationally together. Some heads are as large as three moons.

Among the gases the spectroscope reveals are most deadly poisons.

Their extreme speed would only save us if their passage were distant; in case of crash so much the worse.

These and other astronomical considerations are reinforced by the immoral one that anything so unpleasant is also likely.

The sum of it all is that nobody knows. If destruction by this mode is not to be expected, it is not to be ruled out. We shall lie in our beds without trembling, but we shall respect the fear that inspired our ancestors, and shall ourselves respect⁠—and fear⁠—the next great comet that flames the dark night. Let it be but twice as large and come but twice as near as any of its predecessors, and then let the optimists see. Insane terror will seize them and us all.