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The Earth as seen from other Stars

THERE is hardly anything that could better convey to our minds an idea of the utter insignificance of our earth in stellar space than a representation of the aspect that it would offer us when viewed from the other heavenly bodies. To obtain this view we need not by any means ask our readers to accompany us in an imaginary tour to the fixed stars, for from the nearest of these the earth is invisible, the distance being 225,000 times greater than our distance from the sun. In fact, it has been found by the most eminent astronomers of the age, and the most perfect instruments ever made, that the parallax of the nearest stars does not exceed the four-thousandth part of a decree, or a single second; so that, if the whole great orbit of the earth were lighted up into a globe of Are 600,000,000 miles in circumference, it would be seen from the nearest star only as a twinkling atom; and to an observer placed at this distance our sun, with its whole retinue of planetary worlds, would occupy a space scarcely exceeding the thickness of a spider's web! It will be seen from this, then, that if any of the fixed stars are inhabited, their inhabitants are living in utter ignorance of the existence of our world or of any of the planets of our solar system, and the whole of the latter might be blotted out of existence without any knowledge on their part that such a catastrophe had taken place. Confining ourselves, therefore, to our own planetary system, it is probable that of three planets the inhabitants (if such there be) have as accurate a knowledge of our planet as we have of theirs; while to the others fchere is a great probability that the earth is almost of assmall import ance as it is to the fixed stars. Let us first travel out to the iDDermost of the planets, Mercury, which moves in an orbit 37,000,000 miles from the sun in eighty-eight days, thus giving it a year equal to about three of our months. As the earth revolves in a wider orbit, the best time for the observation from Mercury will be when the sun, Mercury, and the earth stand in a line. Then the side of the earth toward Mercury is illuminated, and our planet is seen by the latter as a large, brilliantly shiDiug star, which, in the accompanying cut, is seen proceeding in the direction of the arrow, from west to east along the zodiac. Seen from Venus, the earth exhibits a much more magnificent aspect. After every five hundred and eighty-four days the two planets are in their nearest proximity, and only about 26,000,000 miles apart. Then the earth appears from Venus like a large, bluish-white, brilliant star, which in size surpasses all others iD the firmanieDt. Iu the accompanying illustration the arrow again shows the direction in which the earth is moving. From the moon the earth presents a still more gorgeous aspect. Its illuminated side is seen to have a diameter something like four times that of the full moon as seen by us, and far surpasses the sun, as well as the planets, in size. It exhibits phases, too, just as we observe them in the moon, and which are in the most beautiful harmony with the needs of the lunar days, these being equal to fifteen of our days. It is, for example, full at midnight, in the last quarter at sunrise, new at midday, and in the first quarter in the evening; so that its light compensates for that of the sun. At “full earth” the lunar inhabitant can distinguish our seas and continents, and see the white shimmer of our polar snows and ice, and the floating clouds in the air. Our atmosphere, which refracts the light from millions of stars, appears like a wan halo investing our globe. As for Mars, which is 145,000,000 miles from the sun, the circumstances are essentially different. While the orbits of the foregoing planets are within that of the earth, Mars' orbit lies immediately outside or beyond. To a spectator on this planet the earth will appear alternately as a morning and evening star, shining with considerable brilliancy, and will exhibit all the phases of the moon, just as Mercury and Venus do to us; and sometimes, like them, will appear to pass over the sun's disk like a dark round spot. Our moon will never appear more than a quarter of a degree from the earth, although its distance from us is 240,000 miles. To the Martial inhabitants the earth will appear larger than Jupiter does to us, and will shine with such brilliancy as to be visible to them even during the daytime. While to the dwellers on Mercury, Venus, the moon, and Mars, our earth maintains the first position among the stars, to those of Jupiter it at once sinks into utter insignificance. The orbit of the latter planet is situated at 496,000,000 miles from the sun, and the distance from the earth varies between 385,000,000 and 625,000,000 miles. It is evident that as the earth never recedes farther than 12° from the sun, it cannot be seen during Jupiter's Dight, for twilight continues a long time after sunset, and when it ends the earth itself is already beneath the horizon. This is the only period at which the earth could be visible, for it is then in its “quarter,” when it is half illuminated by the sun; even then, however, it is most too small to be seen by the naked eye. So i one but astronomers, with their telescopes, could descry our globe from Jupiter; and even then only for a few minutes before sunrise or after sunset, since it quickly disappears, as an insignificant satellite of the sun, in his fiery rays. Now and then, of course, Jupiter's astronomers, in searching for sun spots, may detect a little black dot moving across the solar disk, and which will turn out to be a “transit of the earth,” our magnitude having shrunken to such dimensions when seen from Jupiter! The world of Saturn, with its wonderful rings, is about nine and a half times farther from the sun than the earth is—namely, 909,000,000 miles; and, seen from it, the earth is, at the best, but a mere speck oscillating from one side of the sun to the other. This happens thirty times during the Saturnian year, and never at a greater distance than 6\ Our imaginary view from Saturn embraces an extent of 30° at midnight—that is to say, at the period when the sun, illuminating the planet's immense rings, causes these to appear in its nocturnal sky like two gorgeous arches of light, bright as the full moon, and spanning the whole heavens like a stupendous rainbow. During this wonderful display the Saturnian worlds are undergoing their many quickly-changing phases. The various aspects of the seven moons, one rising above the horizon, while another is setting, and a third approaching the meridian; one entering into an eclipse, and another emerging from one; one appearing as a crescent, and another with a gibbous phase; and sometimes the whole of them shining in the same hemisphere in one bright assemblage, are scenes worthy, indeed, of being contemplated by rational creatures. But the Satur- nians know nothing about our earth; for even if, through the construction of immense telescopes, it were possible for them to see it, it would appear to them as nothing more than a miserable little speck on the sun's disk. Still less visible is the earth from Uranus, which, situated at 1,828,000,000 miles from the sun, receives seventy times less light and heat than the earth does. From here the earth is scarcely any more perceptible even during its transit. Finally, from Neptune, which is 2,862,000,000 miles from the sun, the latter is seen merely as a large star, one-thirtieth of the diameter that it appears to us. To the inhabitants of this planet the earth is absolutely invisible— nil; and, if seen at all, it could only be by the aid of most enormous telescopes. Among all those millions of stars that fill the vast celestial space there are only five, then, or at the best only seven, to whose inhabitants (if such there be) the existence of our globe is known. And yet we dare to apply the term '' world” to our miserable little speck in the universel.

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