The Moon's Face: A Study of the Origin of Its FeaturesPhilosophical Society of Washington, 1893 - 52 páginas |
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The Moon's Face: A Study of the Origin of Its Features Grove Karl Gilbert No hay ninguna vista previa disponible - 2018 |
The Moon's Face: A Study of the Origin of Its Features... - Scholar's Choice ... Grove Karl Gilbert No hay ninguna vista previa disponible - 2015 |
The Moon's Face: A Study of the Origin of Its Features... - Primary Source ... Grove Karl Gilbert No hay ninguna vista previa disponible - 2014 |
Términos y frases comunes
angle of incidence appears bodies cavity central hill circular cliff collision cone congelation cosmic crater forms crater rim crust curve diameter direction distribution district earth earth's attraction ellipticity energy eruption explosion feet fissures flood flow furrows fusion gravitational greater grooves heat Imbrian impact craters impact theory incidence angle inner plain inner slope Julius Cæsar large craters larger lava less liquid lunar craters maar mapped Mare Humorum Mare Imbrium Mare Nubium Mare Serenitatis Mare Tranquilitatis Mare Vaporum maria mass material meteoric theory Meydenbauer miles molten moon moon's face moon's surface moonlets motion mountain Neison number of meteors Oceanus Procellarum orbits outer plain parallel phenomena Phocylides pits plane plastic portion postulated probably ratio relation Rheita ridge rills ring rock rotation sculpture small craters tangential telescopic temperature terraces terrestrial craters tidal tion tract trend valley velocity of impact vertical Vesuvian crater volcanic Wargentin wreath
Pasajes populares
Página 269 - Saturnian ring, by restricting the colliding bodies to a single plane, by substituting a low initial velocity and thus rendering the moon's attraction the dominant influence, and by introducing a system of directions controlling, and therefore adjusted to, the moon's rotation, relieves the meteoric theory of its most formidable difficulty. It also explains in a simple way the abundance of colliding bodies of a different order of magnitude from ordinary meteorites and aerolites. . . . " The velocity...
Página 257 - I have discovered no published statement of meteoric theories more than twenty years old, but the idea is older and various obscure allusions indicate that it was earlier in print. Proctor makes a meteoric suggestion in 1873 (The Moon, p. 346), and advocates it in 1878 (Belgravia, vol. xxxvi, p. 153). A meteoric theory is said to be contained in Die Physiognomie des Mondes, by ' Asterios,
Página 250 - ... per cent of all the visible vents. Ninety-nine per cent of the Vesuvian volcanoes, more or less conical piles, have the bottoms of their craters higher than the corresponding outer plains, while an equal proportion of the lunar "craters" have their bottoms lower than the surrounding plains. Further: Ordinarily the inner height of the lunar crater rim is more than double its outer height; ordinarily the outer height of the Vesuvian crater rim is more than double its inner height. The lunar crater...
Página 289 - ... diameter, more energy would be applied to a unit of space in the case of large moonlets than in the case of small, and the temperatures caused by large moonlets would therefore be greater. To this relation I ascribe the restriction of inner plains, indicative of fusion, to the larger craters. . " In the breaking up of the postulated pre-lunar ring there were at first many centers of aggregation—were the moon the only center, the scars of impact would all be small.
Página 262 - Saturnian ring; that the small bodies constituting this ring afterward gradually coalesced, gathering first around a large number of nuclei, and finally all uniting in a single sphere, the moon. Under this hypothesis the lunar craters are the scars produced by the collision of those minor aggregations, or moonlets, which last surrendered their individuality.
Página 250 - ... Ordinarily the inner height of the lunar crater rim is more than double its outer height; ordinarily the outer height of the Vesuvian crater rim is more than double its inner height. The lunar crater is sunk in the lunar plain; the Vesuvian crater is perched on a mountain top. . . . The smooth inner plain characteristic of so many lunar craters is either rare or unknown in craters of the Vesuvian type. Gilbert concludes: Thus, through the expression of every feature the lunar crater emphatically...
Página 285 - The most remarkable appearance of the Moon, for which nothing on Earth furnishes an example, is presented by those immense radiations from a few of the larger craters — perfectly straight lines, as though marked with chalk along a ruler — starting from the center of the crater and extending to great distances over every obstruction. My explanation is, that a meteorite, striking the Moon with great force, spattered some whitish matter in various directions. Since gravitation is much feebler on...
Página 290 - ... simultaneously in the surface and the subsurface, was dissipated more rapidly from the surface, so that there was a subsurface zone of relatively high temperature. The zone thus inferred deductively is also inferred inductively from the disparity of cavities and rims in the case of large craters; but, on the other hand, there is little evidence of the wrinkling which, theoretically, should result from the adjustment of a cold crust to a cooling nucleus. * * * It is therefore probable that the...
Página 253 - Form differences effectually bar from consideration all volcanic action involving the extensive eruption of lavas, whether dry or saturated with water. They also exclude the maar process (single explosion) as an explanation of medium and large craters, but not as an explanation of small craters. The volcanic theory, as a whole, is therefore rejected, but a limited use may be found for the maar phase of volcanic action in case no other theory proves broad enough for all the phenomena".
Página 242 - not inappropriate to one who has given much thought to the origin of the forms of terrestrial topography", and in this vein hè examined critically the volcanic hypothesis. In half a dozen pages that should still be compulsory reading for selenographers, GILBERT examined the contrasts of size and form and came to the following conclusion: "Form differences effectually bar from consideration all volcanic...