If that star were to burst with a terrific explosion, and if the noise of the catastrophe could be transmitted to us at the ordinary speed of sound in air, we should not hear that explosion until three million years had elapsed after its occurrence. We should see the star shining steadily in the sky for four years after the catastrophe which had destroyed it, because light travels through space with a speed of 186,000 miles a second, and it would have to travel with this constant velocity more than four years before reaching us. Seen from that distance, our brilliant Sun is reduced to the rank of a simple star. The planets which gravitate around it, the Earth, Venus, Mars, Jupiter, Saturn, and their brothers of the solar family, are crowded up against it by the perspective of the distance and are invisibly lost in its rays. Considered at that distance in the sidereal universe, these provinces of the solar empire are recognised as insignificant even by the most optimistic spirit. Even if they did not exist at all, the suns of infinite space would none the less shed their rays of life and light all around. Our planet, which to us seems so important, becomes a microscopic point impossible to discover by means of senses such as ours, and its history told at that distance becomes like the flight of a dragon-fly or even less, since we should never suspect its existence if we did not know it. It is at such moments especially that the pretensions of Pontiffs and the dogmatic assurance of their adepts show forth in all their absurdity. I felt transported into the system of that star, the nearest of all those whose distances have been measured, a star belonging to the constellation of the Centaur; it is the Alpha of that constellation. This system is curious and more interesting than ours. Instead of a single sun corresponding to that which shines upon us, two twin suns gravitate one round the other in a time equalling 81 of our years, and separated from each other by a distance of 2,000 million miles. These twin suns are both of considerable brightness (first and second magnitude, seen from here), and greatly superior to the central hearth of our own system. Planets circulate around each of these luminaries under their protecting wings, and receive from their radiation the sources of their fertility and their life. They are illuminated by two different suns, sometimes united in the same sky, sometimes separated and alternating, differing in magnitude and brightness according to the variation of the distances in consequence of the revolutions of these worlds round their respective centres.