Speaker 1: Section twenty of Sun, Moon and Stars Astronomy for Beginners.
Speaker 1: This is a LibriVox recording. All LibriVox recordings are in
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Speaker 1: and Stars Astronomy for Beginners by Agnes Gibernon. Comets and Meteors.
Speaker 1: It is the glory of God to conceal a thing,
Speaker 1: Proverbs twenty five two. An interesting discovery has been made.
Speaker 1: It appears that some sort of mysterious tie exists between
Speaker 1: comets and meteors. For a long while, this was never suspected.
Speaker 1: How should it be the comets so vast in size,
Speaker 1: the meteor so small and evanescent. How could it possibly
Speaker 1: be supposed that the one had anything to do with
Speaker 1: the other. But supposings often have to give in to facts.
Speaker 1: Astronomers have gradually become convinced that there certainly is a
Speaker 1: connection between the two. Comets and meteor streams are found
Speaker 1: to occupy, sometimes at least, the very same pathways in
Speaker 1: the heavens, the very same orbits around the Sun. A
Speaker 1: certain number of meteor systems are now pretty well known
Speaker 1: to astronomers as regularly met by our Earth at certain
Speaker 1: points in her yearly journey. Some of these systems or
Speaker 1: rings have each a comet belonging to it, not merely
Speaker 1: journey near, but actually in the midst on the same orbit.
Speaker 1: Perhaps it would be more correct to say that the
Speaker 1: meteors belong to the comet than that the comet belongs
Speaker 1: to the meteors. We tread here on uncertain ground. For
Speaker 1: whether the meteors spring from the comet, or whether the
Speaker 1: comet springs from the meteors, or whether both spring from
Speaker 1: the same source, cannot yet be quite definitely asserted, though
Speaker 1: we cannot fully explain the kind of connection. Yet a
Speaker 1: connection there plainly is. So many instances are now known
Speaker 1: of a common and a media ring traveling together, that
Speaker 1: it is doubtful whether any such ring could be found
Speaker 1: without a comet in its midst. By and by, the
Speaker 1: doubt may spring up whether there ever exists a comet
Speaker 1: without a train of meteors following them. Among the many
Speaker 1: different media rings which are known, two of the most
Speaker 1: important are the so called August and November systems. Of
Speaker 1: these two, the November system must claim our chief attention,
Speaker 1: not that we are at all sure of these being
Speaker 1: the most important media rings in the Solar system. On
Speaker 1: the contrary, as regards the November ring, we have some
Speaker 1: reason to think that matters may lie just the other way.
Speaker 1: The comet belonging to the November system is a small one,
Speaker 1: quite an insignificant little comet, only visible through a telescope.
Speaker 1: We do not, of course ow positively that larger comets
Speaker 1: in greater media systems generally go together, but to say
Speaker 1: the least, it seems likely. And if the greatness of
Speaker 1: a ring can at all be judged by the size
Speaker 1: of its comet, then the November system must be a
Speaker 1: third rate specimen of its kind. It is of particular
Speaker 1: importance to us merely because it happens to be the
Speaker 1: one into which our Earth plunges most deeply, and which
Speaker 1: we therefore see and know the best. The August ring is,
Speaker 1: on the contrary, connected with a magnificent comet, and may
Speaker 1: be a far grander system. But our pathway does not
Speaker 1: lead us into the midst of the August meteors, as
Speaker 1: into those of November. We pass seemingly through its outskirts.
Speaker 1: The meteors of the November system are very small. They
Speaker 1: are believed to weigh commonly only a few grains each.
Speaker 1: If they were larger and heavier, some of them might
Speaker 1: find their way to Earth's surface only half diminished in
Speaker 1: their rush through the air, but this they seem never
Speaker 1: to do. Doubtless, meteor systems exist in the Solar System,
Speaker 1: which our Earth does not encounter, containing much larger and
Speaker 1: heavier meteors. It is well for us that we do
Speaker 1: not plunge into any such ring, or we might find
Speaker 1: our atmosphere an insufficient protection. The last grand display of
Speaker 1: the November system of meteorites took place in the years
Speaker 1: eighteen sixty six to eighteen sixty nine, being continued more
Speaker 1: or less during three or four November's following. The next
Speaker 1: grand display is not expected until the year eighteen ninety nine.
Speaker 1: For this system, Leonides, as it is called footnote because
Speaker 1: the falling stars in this display seem all to shoot
Speaker 1: towards us from a spot in the constellation Leo in
Speaker 1: Footnote seems to have a time or year of thirty
Speaker 1: three and a quarter earthly years. The shape of its
Speaker 1: orbit is a very long ellipse, near one end of
Speaker 1: which is the Sun, while the other end is believed
Speaker 1: to reach farther away than the orbit of Uranus. A
Speaker 1: great deal of curiosity has been felt about the actual
Speaker 1: length and breadth and depth of the stream of meteorites
Speaker 1: through which our solid Earth has so often plowed her way.
Speaker 1: During many hours at a time, lookers on have watched
Speaker 1: the magnificent display of heavenly fireworks. Not a mere shooting
Speaker 1: star here and there, as uncommon nights, but radiant meteors
Speaker 1: flashing and dying by thousands through the sky. In eighteen
Speaker 1: sixty six, no less than eight thousand meteors and two
Speaker 1: hours and a quarter were counted from the Greenwich Observatory.
Speaker 1: A natural wonder sprang up in many minds as to
Speaker 1: the extent of the ring from which they fell. For
Speaker 1: not in one night only, but in several nights during
Speaker 1: three or four years, and that not once only, but
Speaker 1: once in every thirty three years, thousands and tens of
Speaker 1: thousands appeared to have been stolen by our Earth from
Speaker 1: the media ring, never again to be restored. Yet each
Speaker 1: time we touched the ring, we find the abundance of
Speaker 1: little meteors in no way seemingly lessened. When speaking of
Speaker 1: a ring of meteors, it must not be supposed that
Speaker 1: necessarily the meteors form a whole broken ring all around
Speaker 1: the long oval orbit. There may be no breaks, there
Speaker 1: may be more or less thin scattering throughout the entire
Speaker 1: length of the pathway. But the meteor certainly seemed to
Speaker 1: cluster far more densely in some parts of the orbit
Speaker 1: than in other parts. And it was about the size
Speaker 1: of the densest cluster that so much curiosity was felt.
Speaker 1: Little can be positively known, though it is very certain
Speaker 1: that the cluster must be enormous in extent. Three or
Speaker 1: four years running, as our Earth, after journeying the whole
Speaker 1: way round the Sun came again to that point in
Speaker 1: her orbit where she passes through the orbit of the Leonides.
Speaker 1: She found the thick stream of meteors still pouring on,
Speaker 1: though each year lessening in amount. Taking into account this
Speaker 1: fact and also the numbers that were seen to fall
Speaker 1: night after night, and also the speed of our Earth,
Speaker 1: a rough estimate was formed. The length of this dense
Speaker 1: cluster is supposed to reach to many hundreds of millions
Speaker 1: of miles. The thickness or depth of the st miscalculated
Speaker 1: to be in parts over hundreds of thousands of miles,
Speaker 1: and the breadth perhaps not less than one hundred thousand miles.
Speaker 1: Each meteor is probably at a considerable distance from his neighbors,
Speaker 1: but the whole mass of them, when in the near
Speaker 1: neighborhood of the Sun, must form a magnificent sight. And
Speaker 1: if this be only a third rate system, what must
Speaker 1: a first rate system be like? And how many such
Speaker 1: systems are there throughout the Sun's wide domains. The most
Speaker 1: powerful telescope gives us no hint of the existence of
Speaker 1: these rings till we find ourselves in their midst It
Speaker 1: may be that they are numbered by thousands, even by millions.
Speaker 1: The whole of the Solar system, Nay, the very depths
Speaker 1: of space beyond may, for aught, we know, be crowded
Speaker 1: with meteor systems. Every comet may have his stream of
Speaker 1: meteors following him, But though the comet is visible to us,
Speaker 1: the meteors are not. Billions upon billions of them may
Speaker 1: be ever rushing round our Sun, entirely beyond our camp
Speaker 1: till one or another straggler touches our atmosphere to flash
Speaker 1: and die as a shooting star. In our sight we have,
Speaker 1: and with our present powers we can have no certainty
Speaker 1: as to all this. But I may quote here the
Speaker 1: illustration of a well known astronomical writer on the subject.
Speaker 1: Suppose a blind man were walking out of doors along
Speaker 1: a high road, and during the course of a few miles,
Speaker 1: were to feel rain falling constantly upon him. Would it
Speaker 1: be reasonable on his part if he concluded that a
Speaker 1: small shower of rain had accompanied him along the road
Speaker 1: as he moved, but that fine weather certainly existed on
Speaker 1: either side of the road. On the contrary, he might
Speaker 1: be sure that the drops which he felt were but
Speaker 1: a few among millions falling altogether. Or look at the
Speaker 1: rain drops on your window some dull ready day. Count
Speaker 1: how many there are? Could you, with any show of
Speaker 1: common sense, decide that those rain drops, and those alone,
Speaker 1: had fallen that day in your town. So when we
Speaker 1: find these showers of meteors falling to earth, we may
Speaker 1: safely conclude that for every one which touches our atmosphere,
Speaker 1: myriads rush elsewhere in space, never coming near us. End
Speaker 1: of section twenty