Voyager 1 May Soon Cross into Inter-stellar Space
by Jacqueline Dennison
Once a pioneer of our solar
system’s giant planets, NASA’s
Voyager 1 may soon be the first
man-made space probe to
venture beyond our Solar System
and into inter-stellar space.
Recent data suggests that
Voyager has entered the outer
edge of the solar system, an area
teeming with charged particles
believed to have originated from
our neighboring stars. Readings of
particles from our own star have
slowed, another indication that Voyager is close to breaking the solar boundary.
Ed Stone, Voyager project scientist at California Institute of Technology, has
given an optimistic view of Voyager’s journey. “The laws of physics say that
someday Voyager will become the first human-made object to enter interstellar
space, but we still do not know exactly when that someday will be,” said Stone.
“The latest data indicate that we are clearly in a new region where things are
changing more quickly. It is very exciting. We are approaching the solar system’s
Voyager 1 is travelling through the heliosheath, the turbulent outer edge of the
solar system where charged particles from the Sun are very active.
“From January 2009 to January 2012, there had been a gradual increase of
about 25 percent in the amount of galactic cosmic rays Voyager was encountering,”
said Stone. “More recently, we have seen very rapid escalation in that part of the
energy spectrum. Beginning on May 7, the cosmic ray hits have increased five percent
in a week and nine percent in a month.”
Since its launch in 1977, Voyager 1 has traveled to over 18 billion kilometers
from the Sun. Its sister probe, Voyager 2, is about 15 kilometers from the sun.
Between them, the two probes have visited the giant planets Jupiter, Saturn, Uranus
and Neptune, as well as 48 moons. Both Voyagers each carry a gold-plated copper
record that plays various sounds from Earth, including greetings in 55 languages.
The golden records, put together by a committee headed by astronomer Carl Sagan,
were included for any extra-terrestrials who may come into contact with the Voyager
“When the Voyagers launched in 1977, the space age was all of 20 years old,”
said Stone. “Many of us on the team dreamed of reaching interstellar space, but we
really had no way of knowing how long a journey it would be — or if these two vehicles
that we invested so much time and energy in would operate long enough to reach it.”
When Voyager ventures into inter-stellar space, it will mark a milestone in
human space exploration.