it's been traveling for nearly 12 years
it has already logged more than 4
billion miles in its lifetime it's been
to places humans had once only dreamed
about and on August twenty-fourth 1989
at nine p.m. pacific daylight time
Voyager 2 will make history again
it will become the first spacecraft to
fly by Neptune a planet that orbits the
Sun near the edge of our solar system
launched in 1977 Voyager 1 and 2 have
taken us to Jupiter and Saturn when
Voyager 1 flew past the large moon Titan
and behind Saturn's rings its flight
path was bent northward and the
spacecraft was sent out of the ecliptic
plane and on toward interstellar space
Voyager 2 is on a flight path it takes
advantage of a rare geometric
positioning of the outer planets this
allows Voyager 2 to use the gravity of
the planets it's encountered to boost it
from one to another without onboard
propulsion Neptune is invisible to the
naked eye even our biggest telescopes
can see only broad features of the
planet early pictures sent back from
Voyager already show cloud features and
a dark band of clouds and circling the
southern pole Neptune's diameter is
about four times the size of Earth it's
blue green color comes from atmospheric
methane which absorbs red light in orbit
around Neptune our ring arcs and one of
the larger and most interesting moons in
the solar system Triton at Voyager tues
closest approach it will pass just 3,000
miles from Neptune's cloud tops that's
closer than Voyager 2 has come to any
other planet a few days before the
spacecraft arrives at Neptune engineers
will fine-tune voyagers flight path over
Neptune's North Pole Voyager will be
able to detect any Neptunian magnetic
field and is likely to pass through the
region where the Northern Lights form
despite Neptune's greater distance from
the Sun its temperature is the same as
that of Uranus for it to be so warm and
yet so far away Neptune must generate
some internal heat of its own another of
Neptune's mysteries is it's moon Triton
with a presumed atmosphere of methane
and possibly nitrogen Triton is expected
to be one of the most fascinating
objects and counted in Voyager tues
entire journey because Neptune is so far
away radio data from Voyager traveling
at the speed of light will take four
hours and six minutes to reach Earth the
signals are received through the Deep
Space Network a global spacecraft
tracking and communication system
operated by the Jet Propulsion
Laboratory for NASA to provide
continuous two-way contact with the
spacecraft DSN antenna stations are
strategically located in California's
Mojave Desert near Madrid Spain and near
Canberra Australia the father away
Voyager goes the more difficult it is to
pick up its weak signal to make up for
this the DSN antennas have been enlarged
and are now able to collect more and
higher quality data from the spacecraft
the Parkes radio Observatory in
Australia and the National Radio
Astronomy Observatory's Very Large Array
in New Mexico will join the DSN antennas
to provide for additional receiving
power the asudar tracking station in
japan will help conduct radio science
experiments with the encounter of
Neptune Voyager 2 will complete its
grand tour of the four giant outer
planets and head for its next adventure
the spacecraft is expected to continue
to send back valuable data well into the
21st century as voyager 2 reaches for
the edge of our solar system and enters
interstellar space once there Voyager
will again stretch our imagination as it
discovers for us things we haven't even
anticipated