The Heavens: An Illustrated Handbook of Popular AstronomyScribner, Welford & Company, 1871 - 432 pages |
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Common terms and phrases
aphelion appearance Arago astronomers atmosphere axis brightness brilliant celestial bodies celestial vault centre clouds colour comets constellation craters dark density described diameter dimensions disappear disk double stars Earth equator equatorial equinox extreme fact globe heat heavens hemisphere Herschel horizon hypothesis immense intensity Jupiter Lastly length less light luminous points lunar Mädler Mars mass mean distance measure Mercury meteors miles Milky minor planets Moon Moon's movement of rotation naked eye nearly nebula night nucleus observed orbit pass penumbra perihelion period phases phenomena photosphere physical constitution planet planetary pole portion position present proper motion rays regions remarkable revolution ring round the Sun satellites Saturn second magnitude seen sidereal sidereal day solar day solar system sometimes southern space sphere spots starry vault stars visible Sun's surface telescope terrestrial total eclipse traverse umbra Uranus variable variable stars varies velocity Venus whilst Zodiacal Light zone
Popular passages
Page 233 - We see it as Columbus saw America from the shores of Spain. Its movements have been felt trembling along the far-reaching line of our analysis with a certainty hardly inferior to ocular demonstration.
Page 97 - Astronomers, with a view of obtaining a convenient and uniform measure of time, have recourse to a mean solar day, the length of which is equal to the mean or average of all the apparent solar days in a year. An imaginary Sun, called the mean Sun...
Page 143 - Fahrenheit, would create cellular space equal to nearly 14J millions of cubic miles, which would be more than sufficient to engulf the whole of the lunar oceans, supposing them to bear the same proportion to the mass of the Moon as our own oceans bear to that of the Earth.
Page 143 - Now, if such be the present condition of the Moon, we can scarcely avoid the conclusion that a liquid ocean can only exist upon the surface of a planet so long as the latter retains a high internal temperature.
Page 140 - Beyond the second ridge a talus slopes gradually down north ward» to the general level of the lunar surface, the whole presenting an appearance reminding the observer of the concentric moraines of the Rhone glacier. These ridges are visible for the whole period during which that portion of the moon's surface is illuminated, but it is only about the third day after the first quarter and at the corresponding phase of the waning moon (when the sun's rays falling nearly horizontally, throw the details...
Page 140 - ... and streaks of the lunar surface, are not improbably due to former glacial action. Notwithstanding the excellent definition of modern telescopes, it could not be expected that other than the most gigantic of the characteristic details of an ancient glacier bed would be rendered visible.
Page 46 - If we may suppose the so-called " willow-leaves" — the " things " on the Sun, to be the tops of the currents ascending from the Sun's body, what changes of appearance are they likely to undergo in the neighbourhood of a cyclone? For some distance round a cyclone there will be a drawing-in of the superficial gases towards the vortex. All the luminous spaces of more transparent clouds, forming the adjacent photosphere, will be changed in shape by these centripetal currents ; they will be greatly...
Page 173 - ... the most remote condition, of which we have positive evidence, was that of small, detached, melted globules, the formation of which cannot he explained in a satisfactory manner, except by supposing that their constituents were originally in the state of vapour, as they now exist in the atmosphere of the Sun ; and, on the temperature becoming lower, condensed into these
Page 187 - seems above all to confirm the idea of an intimate relation between all the minor planets ; it is, that, if their orbits are figured under the form of material rings, these rings will be found so entangled, that it would be possible, by means of one among them taken at hazard, to lift up all the rest.
Page 140 - ... of controversy. In conclusion, this hypothesis suggests the probability that the other bodies belonging to our solar system have either already passed through a similar epoch, or are destined still to encounter it. With the exception of the polar ice of Mars we have hitherto obtained no certain glimpse into the thermal or meteorological condition of the planets : neither is the physical state of their surfaces accessible to our best telescopes. It is otherwise however with the moon, whose distance...