Ringmakers of Saturn PDF - Patrick Crusade

RINGMAKERS OF SATURN
collision would not occur, of course, were the vehicles in different
planes or were one to surrender its position to the other. Preference is
for the latter. Excluding bulb luminous sources, Plates 5 and 6 tend to
show that vehicle diameter is an approximate measure of thickness of
the A ring at inception. For the time frame shown then, maximum ring
thickness inferentially would be of the order of 2785 km (1730 mi).
Obviously, at large distances from the vehicle, at the ring edges and for
old trails, the ring would be expected to be much thinner and more
diffuse.
Plates 3, 5 and 6 confirm the early observations of moving luminous
sources by Herschel, Knight and Ainslie. Herschel is credited with a
source of variable luminosity, possibly of a fiery character. Knight and
Ainslie reported a luminous source as bright as a star. Both descriptions
fit acceptably well that which is discerned from the three plates.
An additional commonality exists between the Knight-Ainslie event
and the two vehicles in Plates 5 and 6. Specifically, the chordal path of
the Knight-Ainslie moving source is the same chordal element defined
by the location and orientation of the two vehicles. Whether these
chords are in the same approximate position around the ring is beyond
the scope of this inquiry.
Plates 5 and 6 reveal that width of the Cassini division occurs neither
accidentally nor with exact repeatability. The reason is that the basic
spacing depends upon the radius at which a mobile vehicle orbits with
respect to the B ring. Even though this orbital radius might be
constant, a substantial degree of variability in character of the trailing
flux can alter the radial location of the inner edge of the A ring. Also,
the extent of flux emission along the length of a vehicle can influence
the width of the Cassini division. These possibilities for differences
explain the variability in measurements by different observers over the
years. Fairly narrow tolerances, astronomically speaking, on the
radius of the B-ring outer edge and the A-ring inner edge have led
observers to conclude that the Cassini division is a true gap. That the
Enke division is a true gap has been doubted because of its apparent
absence from time to time. Actually, the Enke division is formed in the
same manner as the Cassini division and in this sense, the Enke gap is
just as true a one as the Cassini gap.
Plate 7 shows formation of the Enke division. In the plate, the A and
B rings as well as the Cassini division can be recognized. Once again, a
vehicle is found depositing an orbital trail. Efflux emanating primarily
from the radially outboard 2/3 of body length is responsible. Clearly,
were the vehicle located at a slightly shorter radius, the gap would be
lessened. Widths reported for the Enke division range from approxi-
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