Cosmos: A Sketch of the Physical Description of the Universe, Vol. 1Humboldt, Alexander von
History
Cosmos: A Sketch of the Physical Description of the Universe, Vol. 1
Humboldt, Alexander von
Astronomy; Cosmography; Physical geography; Science -- History
Uranus appears to be denser than Saturn, even if we adopt the smaller mass,
1/24605, assumed by Lamont; and, notwithstanding the inconsiderable
difference of density observed in the innermost planetary group,* we find
both Venus and Mars less dense than the Earth, which lies between them.
[footnote] *On the arrangement of masses, see Encke, in Schum., 'Astr.
Nachr', 1843 Nr. 488, 114.
The time of rotation certainly diminishes with increasing solar distance,
but yet it is greater in Mars than in the Earth, and in Saturn than in
Jupiter. The elliptic
p 94
orbits of Juno, Pallas, and Mercury have the greatest degree of
eccentricity, and Mars and Venus, which immediately follow each other, have
the least. Mercury and Venus exhibit the same contrasts that may be
observed in the four smaller planets, or asteroids, whose paths are so
closely interwoven.
The eccentriciities of Juno and Pallas are very nearly identical, and reach
three times as great as those of Ceres and Vesta. The same may be said of
the inclination of the orbits of the planets toward the plane of projection
of the ecliptic, or in the position of their axes of rotation with relation
to their orbits, a position on which the relations of climate, seasons of
the year, and length of the days depend more than on eccentricity. Those
planets that have the most elongated elliptic orbits, as Juno, Pallas, and
Mercury, have also, although not to the same degree their orbits most
strongly inclined toward the ecliptic. Pallas has a comet-like inclination
nearly twenty-six times greater than that of Jupiter, while in the little
planet Vesta, which is so near Pallas, the angle of inclination scarcely by
six times exceeds that of Jupiter. An equally irregular succession is
observed in the position of the axes of the few planets (four or five) whose
planes of rotation we know with any degree of certainty. It would appear
from the position of the satellites of Uranus, two of which, the second and
fourth, have been recently observed with certainty, that the axis of this,
the outermost of all the planets is scarcely inclined as much as 11 degrees
toward the plane of its orbit, while Saturn is placed between this planet,
whose axis almost coincides with the plane of its orbit, and Jupiter, whose
axis of rotation is nearly perpendicular to it.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account