Episode Transcript
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Speaker 1 (00:02):
Welcome to brain Stuff from How Stuff Works. Hey, brain Stuff,
it's Christian Sager. On September five, nineteen seventy seven, NASA's
historic Voyager one mission launched, joining its identical robotic twin
Voyager two, on what would turn out to be a
forty year odyssey through the Solar System and into interstellar space.
(00:26):
Voyager two had launched more than two weeks earlier on
August nineteen seventy seven, and both spacecraft completed the dazzling
grand tour of the Outer Solar System's planets. Voyager one
has now left our sons heliosphere, becoming a bona fide
interstellar probe and the most distant human made vehicle, and
(00:48):
Voyager two is about to flirt with the outermost boundary
of the Heliosphere the Helio Pause. But exploring interstellar space
wasn't a mission objective back in nineteen seventy seven. Back then,
the twin probes aim was to reveal the rich, diversity
and mystery of the Outer Solar System's planets. For Ed Stone,
(01:10):
who has been project scientists for the Voyagers since nineteen
seventy two, his favorite memory was the jaw dropping discovery
of volcanoes on Jupiter's moon Io in nineteen seventy nine.
He said the eruptions on Io were the first direct
evidence of active volcanoes elsewhere in the Solar System, and
he wasn't wrong. Both Voyager one and two changed our
(01:33):
perspective of our Solar System, revealing never before seeing details
in planetary atmospheres and revealing new discoveries about interplanetary space.
New insights to Saturn's beautiful rings were gleaned, and a
huge diversity of moons swarming around the gas giants was revealed.
There are few more visceral science impacts on society than
(01:57):
when in nineteen ninety Voyager one was commanded to turn
around and capture an image of Earth from nearly four
billion miles or six point four billion kilometers distant. This
was at the request of Superstar astronomer and science communicator
Carl Sagan. In an interview with space dot Com, Stone
(02:19):
estimated that both spacecraft only have about ten years supply
of power left before the plutonium heat output dwindles, two
levels that won't sustain any spacecraft instrumentation or critical subsystems.
Though the Voyagers will eventually die, they continue to take data,
and Voyager one is taking measurements of a very alien
(02:42):
region the interstellar medium. On August two thousand and twelve,
NASA confirmed that Voyager one had officially left the heliosphere,
speeding into interstellar space. Voyager two is traveling in a
different direction and has an encountered interstellar space. It The
mysterious outermost regions of the Solar System have now been probed,
(03:04):
and Voyager one was able to take measurements of the
magnetic field and particle energies, important measurements that have allowed
scientists a very privileged view of how our Son's magnetic
field and solar wind particles interact with the space between
the stars. So, after four decades of exploration, two spacecraft
(03:26):
built from nineteen seventies technology are still exploring, and a
new generation of scientists are using them to carry out
cutting edge research in a region of space that no
other robot that we know of has ever experienced. Even
after their power supplies dwindle and the Voyagers lose communication
(03:46):
with Earth, they will be silent interstellar emissaries for humanity,
carrying the Golden records as shrines of the civilization that
built these incredible machines should an extraterrestrial and elligence stumble
upon them and the eons to come. Today's episode was
(04:10):
written by Ian O'Neill, produced by Dylan Fagan, and For
more on this and other topics, please visit us at
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