January 2017

EDUCATION
by Bill Johnson
A fresh look at
Voyager’s
astounding journey
by Bill Johnson
As a nation, we’ve become
nonchalant about space exploration.
Since we stood in awe of a man on
the moon and spaceships blasting off from
Cape Canaveral, the budget and mission
of the National Aeronautics and Space
Administration was dramatically reduced,
private companies began experimenting
with space travel, and we now depend
on Russia to carry American astronauts to
and from the international space station
that orbits the Earth every 92 minutes.
Nonetheless, unless you’re a space
science geek who lives with this stuff day
in and day out, some of what’s going on
out there can boggle your mind. Consider
this: It’s been about 40 years since NASA
launched the Voyager on its mission.
You’ve probably forgotten about it, if you
ever even paid attention from the get-go.
But since 1977, way back when Jimmy
Carter was president, Voyager has been
going…and going…and going.
Each hour that passes Voyager is 38,000
more miles from Earth. On its way it
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revealed previously unknown facts about
the planets Jupiter and Saturn and taught
us there are active volcanoes on one of
Jupiter’s moons.
Perhaps the most amazing thing is that
Voyager has gone to reveal secrets of a
place where nothing associated with man
has ever gone. It’s called interstellar space.
Imagine that our solar system is in a huge
bubble that’s called the heliosphere. (NASA
scientists describe the bubble more as an
elongated windsock.) In the heliosphere
the sun produces what are called solar
winds, electrically charged gas that spews
out at more than a million miles an hour.
But they go only so far. Beyond that —
beyond the heliosphere — is interstellar
space. That’s where Voyager is and it’s
still communicating with us, responding
to signals, and providing information.
Because of the vast distance and the
speed that electronic messages can travel,
it takes many hours for a message to
get there. Scientists tell us that by 2020
Voyager will run out of power, and we can
bid it adieu. It will then be about 13.8 billion
miles from us, if you can even imagine that.
What next? It may drift forever, wandering
the Milky Way.
I should mention than when referring
to Voyager, I’ve referred specifically to
Voyager I, which is a kind of companion to
another explorer, Voyager II, which has its
own story.
JANUARY 2017
Just in case these things end up in the
hands of intelligent life, there’s a copper
disc aboard to reveal something about
Earth. The iconic astrophysicist Carl
Sagan headed a project to decide what
information should be on the disc. First,
there are visual instructions on how to
play the disc, presuming that an intelligent
life form could figure out to follow them.
Included in the sounds of Earth are whale
calls, birdcalls, thunder, and the sound of
surf. Information is communicated through
symbols of mathematics and science.
From all of this, who knows what else
we’ll learn and how that knowledge may
be used. In the early 1500s Copernicus
developed the knowledge that Earth
was not the center of the universe, and
Galileo was later denounced as a heretic
and given house arrest for spreading that
theory. Discoveries can be unsettling.
What about scientists today who imagine
things that you and I have never imagined
– things beyond the heliosphere, into
interstellar space? What can we possibly
learn, and what can such exploration teach
us? We can’t begin to say. The human
brain is a restless thing that won’t be
stilled or constrained by convention. There
will always be a Galileo, a Copernicus, a
Carl Sagan, or Stephen Hawking, whose
genius or unbounded scientific curiosity will
force us to see far beyond the stars. If only
we could know now what they will later
teach us. P