When I read in my morning’s paper of the “Nova” in the constellation of Sagittarius, I thought first of H. G. Wells’s story of “The New Star,” and smiled. Later, I turned with a little shiver of anxiety to that chapter in Professor Lowell’s _Evolution of Worlds_ in which he describes the possible coming of a “dark stranger” out of the depths of space. Already there were points of striking resemblance between Lowell’s imaginative account and the details that were appearing casually, in the intervals between more important news, in the newspapers. This new star differed from those other _novæ_ so many of which have been recorded at various times. _They_ brought us tidings of a collision that had already occurred, blazing out suddenly into a short-lived splendour and quickly waning again to invisibility. This stranger, astronomers were agreed, shone not by its own light but by the reflected light of the sun. Then it must be, relatively, near. Lowell’s calculations gave us something like thirty years to prepare before the invader wrought the destruction of the solar system. But, obviously, that calculation depended on various assumptions that the reality need not verify. This strange visitor might be much smaller than he had assumed--he had taken the enormous mass of the sun as his standard--its albedo might be lower; its speed greater. Also Lowell’s stranger was assumed to be coming at right angles to the plane of the ecliptic; this one would, as it were, skim the edge of that swimming saucer. Would any of the outer planets be interposed between us and this dreadful visitor? Neptune, Uranus, Saturn, Jupiter, Mars, might any of them be a buffer to us--provide us, perhaps, with some stupendous display in the heavens, but save us from ultimate disaster? Everyone treated the thing so lightly. Here and there alarmist paragraphs appeared, but they only displayed the hand of the sensation-monger. No one took the threat seriously. And yet the astronomers must know? They had had more than a week, now, in which to make their calculations. And then the shadow fell with such suddenness that it was impossible to say how the certainty had come to us. Everyone knew. The astronomers confirmed one another without a dissentient. And there was nothing in the way. With a horrible unanimity the outer planets had left a clear space for the intruder, while the Earth, with that blundering indifference which is surely its chief characteristic, was stolidly marching straight into the path of destruction. Is there any esoteric significance in the fact that the Earth has a greater density than any other member of the solar system?