A Journey in Other Worlds [41]
what produces it I
confess I am unable to explain. I also see why the tail always
stretches away from the sun, because near by it is overwhelmed by
the more powerful light; in fact, I suspect it is principally in
the comet's shadow that the tail is visible. It is strange that
no one ever thought of that before, or that any one feared the
earth's passing through the tail of a comet. It is obvious to me
now that if there were any material substance, any gas, however
rarefied, in this hairlike[1] accompaniment, it would immediately
fall to the comparatively heavy head,
and surround that as a centre."
[1] Comet means literally a hair.
"How, then," asked Cortlandt, "do you account for the spaces
between those stones? However slight gravitation might be
between some of the grains, if it existed at all, or was
unopposed by some other force, with sufficient time--and they
have eternity--every comet would come together like a planet into
one solid mass. Perhaps some similar force maintains gases in
the distended tail, though I know of no such, or even any
analogous manifestation on earth. If the law on which we have
been brought up, that 'every atom in the universe attracts every
other atom,' were without exceptions or modifications, that comet
could not continue to exist in its present form. Until we get
some additional illustration, however, we shall be short of data
with which to formulate any iconoclastic hypothesis. The source
of the light, I must admit, also puzzles me greatly. There is
certainly no heat to which we can attribute it."
Having gone beyond the fragments, they applied a strong repulsion
charge to the comet, creating thereby a perfect whirlpool among
its particles, and quickly left it. Half an hour later they
again shut off the current, as the Callisto's speed was
sufficient.
For some time they had been in the belt of asteroids, but as yet
they had seen none near. The morning following their experience
with the comet, however, they went to their observatory after
breakfast as usual, and, on pointing their glasses forward,
espied a comparatively large body before them, a little to their
right.
"That must be Pallas," said Cortlandt, scrutinizing it closely.
"It was discovered by Olbers, in 1802, and was the second
asteroid found, Ceres having been the first, in 1801. It has a
diameter of about three hundred miles, being one of the largest
of these small planets. The most wonderful thing about it is the
inclination of its orbit--thirty-five degrees--to the plane of
the ecliptic; which means that at each revolution in its orbit,
it swings that much above and below the imaginary plane cutting
the sun at its equator, from which the earth and other larger
planets vary but little. This no doubt is due to the near
approach and disturbing attraction of some large comet, or else
it was flung above or below the ordinary plane in the catastrophe
that we think befell the large planet that doubtless formerly
existed where we now find this swarm. You can see that its path
makes a considerable angle to the plane of the ecliptic, and that
it is now about crossing the line."
It soon presented the phase of a half moon, but the waviness of
the straight line, as in the case of Venus and Mercury, showed
that the size of the mountains must be tremendous compared with
the mass of the body, some of them being obviously fifteen miles
high. The intense blackness of the shadows, as on the moon,
convinced them there was no trace of atmosphere.
"There being no air," said Cortlandt, "it is safe to assume there
is no water, which helps to account for the great inequalities on
the body's surface, since the mountains will seem higher when
surrounded by dry ocean- bottom than they would if water came
halfway up their sides. Undoubtedly, however, the main cause of
their height is the slight effect of gravitation on an asteroid,
and the fact that the shrinking of the interior, and consequent
folding of the crust in ridges, may have
confess I am unable to explain. I also see why the tail always
stretches away from the sun, because near by it is overwhelmed by
the more powerful light; in fact, I suspect it is principally in
the comet's shadow that the tail is visible. It is strange that
no one ever thought of that before, or that any one feared the
earth's passing through the tail of a comet. It is obvious to me
now that if there were any material substance, any gas, however
rarefied, in this hairlike[1] accompaniment, it would immediately
fall to the comparatively heavy head,
and surround that as a centre."
[1] Comet means literally a hair.
"How, then," asked Cortlandt, "do you account for the spaces
between those stones? However slight gravitation might be
between some of the grains, if it existed at all, or was
unopposed by some other force, with sufficient time--and they
have eternity--every comet would come together like a planet into
one solid mass. Perhaps some similar force maintains gases in
the distended tail, though I know of no such, or even any
analogous manifestation on earth. If the law on which we have
been brought up, that 'every atom in the universe attracts every
other atom,' were without exceptions or modifications, that comet
could not continue to exist in its present form. Until we get
some additional illustration, however, we shall be short of data
with which to formulate any iconoclastic hypothesis. The source
of the light, I must admit, also puzzles me greatly. There is
certainly no heat to which we can attribute it."
Having gone beyond the fragments, they applied a strong repulsion
charge to the comet, creating thereby a perfect whirlpool among
its particles, and quickly left it. Half an hour later they
again shut off the current, as the Callisto's speed was
sufficient.
For some time they had been in the belt of asteroids, but as yet
they had seen none near. The morning following their experience
with the comet, however, they went to their observatory after
breakfast as usual, and, on pointing their glasses forward,
espied a comparatively large body before them, a little to their
right.
"That must be Pallas," said Cortlandt, scrutinizing it closely.
"It was discovered by Olbers, in 1802, and was the second
asteroid found, Ceres having been the first, in 1801. It has a
diameter of about three hundred miles, being one of the largest
of these small planets. The most wonderful thing about it is the
inclination of its orbit--thirty-five degrees--to the plane of
the ecliptic; which means that at each revolution in its orbit,
it swings that much above and below the imaginary plane cutting
the sun at its equator, from which the earth and other larger
planets vary but little. This no doubt is due to the near
approach and disturbing attraction of some large comet, or else
it was flung above or below the ordinary plane in the catastrophe
that we think befell the large planet that doubtless formerly
existed where we now find this swarm. You can see that its path
makes a considerable angle to the plane of the ecliptic, and that
it is now about crossing the line."
It soon presented the phase of a half moon, but the waviness of
the straight line, as in the case of Venus and Mercury, showed
that the size of the mountains must be tremendous compared with
the mass of the body, some of them being obviously fifteen miles
high. The intense blackness of the shadows, as on the moon,
convinced them there was no trace of atmosphere.
"There being no air," said Cortlandt, "it is safe to assume there
is no water, which helps to account for the great inequalities on
the body's surface, since the mountains will seem higher when
surrounded by dry ocean- bottom than they would if water came
halfway up their sides. Undoubtedly, however, the main cause of
their height is the slight effect of gravitation on an asteroid,
and the fact that the shrinking of the interior, and consequent
folding of the crust in ridges, may have