These are the most frequently used words in this book.
1986
al
approach
approximately
asteroids
au
between
bodies
cloud
co
coma
comet
cometary
courtesy
data
density
discovery
distance
distribution
dust
earth
effect
emission
energy
et
events
field
fig
figure
first
force
found
gas
halley
ice
images
impact
inner
ions
jupiter
km
large
lines
magnetic
major
mass
material
may
mission
model
molecules
motion
near
new
nucleus
number
objects
observations
observed
orbit
orbital
particles
perihelion
period
planets
plasma
point
process
range
rate
region
results
section
see
should
shown
shows
size
small
solar
source
space
spacecraft
speed
stars
structure
study
sun
surface
system
tail
temperature
thus
time
two
used
value
water
wind
years