The Heavens, an Illus. Handbook of Popular AstronomyBentley, 1872 - 432 síður |
Aðrar útgáfur - View all
The Heavens, an Illus. Handbook of Popular Astronomy Amedee Victor Guillemin Engin sýnishorn í boði - 2023 |
The Heavens, an Illus. Handbook of Popular Astronomy Amedee Victor Guillemin Engin sýnishorn í boði - 2015 |
The Heavens, an Illus. Handbook of Popular Astronomy Amedee Victor Guillemin Engin sýnishorn í boði - 2023 |
Common terms and phrases
aphelion appearance Arago astronomers atmosphere axis brightness brilliant celestial bodies celestial vault centre clouds colour comets constellation craters dark described diameter dimensions disappear disk double stars Earth entire equator equatorial 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 spectrum 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
Vinsælir kaflar
Síða 105 - As has been mentioned, the time shown by a sundial is called Apparent Solar Time. It differs from Mean Solar Time by an amount known as the Equation of Time, which is the total effect of two causes which make the length of the apparent solar day nonuniform.
Síða 185 - ... minutes, 3-5 seconds. Thus a whole day of Mars exceeds one of our days by 39 minutes 35 seconds. The difference is not very perceptible. Besides, the inclination of the axis of rotation to the plane of the ecliptic is nearly the same as that of the axis of the...
Síða 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...
Síða 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.
Síða 173 - ... the most remote condition, of which we have positive evidence, was that of small, detached, melted globules, the formation of which cannot be 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
Síða 140 - Beyond the second ridge a talus slopes gradually down northwards 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...
Síða 32 - Noble.; those portions occupied by the spots, is coarsely mottled; and, indeed, the mottled appearance requires no very large amount of optical power to render it visible.
Síða 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.
Síða 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.
Síða 50 - ... our own atmosphere near the sea-level. This would seem to dispose of the theory that the corona seen during total eclipses is an atmosphere of the Sun; for in that case the pressure at the Sun's surface could scarcely fail to be enormously greater than it is observed to be. Mr. Lockyer therefore considers that the corona is not a solar appendage at all, but due to the passage ' of the Sun's rays through our own atmosphere near the Moon's place...