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it's been traveling for nearly 12 years

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it has already logged more than 4

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billion miles in its lifetime it's been

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to places humans had once only dreamed

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about and on August twenty-fourth 1989

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at nine p.m. pacific daylight time

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it will become the first spacecraft to

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fly by Neptune a planet that orbits the

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launched in 1977 Voyager 1 and 2 have

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taken us to Jupiter and Saturn when

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Voyager 1 flew past the large moon Titan

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and behind Saturn's rings its flight

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path was bent northward and the

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spacecraft was sent out of the ecliptic

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plane and on toward interstellar space

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Voyager 2 is on a flight path it takes

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advantage of a rare geometric

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positioning of the outer planets this

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allows Voyager 2 to use the gravity of

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the planets it's encountered to boost it

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from one to another without onboard

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propulsion Neptune is invisible to the

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naked eye even our biggest telescopes

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can see only broad features of the

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planet early pictures sent back from

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Voyager already show cloud features and

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a dark band of clouds and circling the

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southern pole Neptune's diameter is

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about four times the size of Earth it's

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blue green color comes from atmospheric

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methane which absorbs red light in orbit

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around Neptune our ring arcs and one of

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the larger and most interesting moons in

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the solar system Triton at Voyager tues

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closest approach it will pass just 3,000

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miles from Neptune's cloud tops that's

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closer than Voyager 2 has come to any

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other planet a few days before the

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spacecraft arrives at Neptune engineers

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will fine-tune voyagers flight path over

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Neptune's North Pole Voyager will be

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able to detect any Neptunian magnetic

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field and is likely to pass through the

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region where the Northern Lights form

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despite Neptune's greater distance from

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the Sun its temperature is the same as

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that of Uranus for it to be so warm and

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yet so far away Neptune must generate

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some internal heat of its own another of

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Neptune's mysteries is it's moon Triton

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with a presumed atmosphere of methane

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and possibly nitrogen Triton is expected

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to be one of the most fascinating

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objects and counted in Voyager tues

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entire journey because Neptune is so far

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away radio data from Voyager traveling

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at the speed of light will take four

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hours and six minutes to reach Earth the

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signals are received through the Deep

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Space Network a global spacecraft

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tracking and communication system

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operated by the Jet Propulsion

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Laboratory for NASA to provide

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continuous two-way contact with the

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spacecraft DSN antenna stations are

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strategically located in California's

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Mojave Desert near Madrid Spain and near

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Canberra Australia the father away

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Voyager goes the more difficult it is to

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pick up its weak signal to make up for

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this the DSN antennas have been enlarged

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and are now able to collect more and

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higher quality data from the spacecraft

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the Parkes radio Observatory in

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Australia and the National Radio

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Astronomy Observatory's Very Large Array

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in New Mexico will join the DSN antennas

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to provide for additional receiving

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power the asudar tracking station in

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japan will help conduct radio science

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experiments with the encounter of

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Neptune Voyager 2 will complete its

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grand tour of the four giant outer

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the spacecraft is expected to continue

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to send back valuable data well into the

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21st century as voyager 2 reaches for

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the edge of our solar system and enters

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interstellar space once there Voyager

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will again stretch our imagination as it