- WASHINGTON (Reuters) - NASA's
Voyager 1 has reached the final frontier of our solar system, having traveled
through a turbulent place where electrically charged particles from the
Sun crash into thin gas from interstellar space.
- Astronomers tracking the little spaceship's 26-year journey
from Earth believe Voyager 1 has gone through a region known as termination
shock, some 8.7 billion miles from the Sun, and entered an area called
- "Voyager 1 has entered the final lap on its race
to the edge of interstellar space," Edward Stone, Voyager project
scientist at the California Institute of Technology, said in a statement
- Voyager watchers theorized last November that the craft
might be reaching this bumpy region of space when the charged solar particles
known as the solar wind seemed to slow down from a top speed of 1.5 million
miles per hour.
- This was expected at the area of termination shock, where
the solar winds were expected to decelerate as they bump up against gas
from the space beyond our solar system. It is more than twice as distant
as Pluto, the furthest planet in our system.
- By monitoring the craft's speed and the increase in the
force of the solar wind, Voyager scientists now believe the craft has made
it through the shock and into the heliosheath.
- Predicting the location of the termination shock was
hard because the precise conditions in interstellar space are unknown and
the termination shock can expand, contract and ripple, depending on changes
in the speed and pressure of the solar wind.
- "Voyager's observations over the past few years
show the termination shock is far more complicated than anyone thought,"
said Eric Christian, a scientist with NASA's Sun-Solar System Connection
- Voyager 1 and its twin spacecraft Voyager 2 were launched
in 1977 on a mission to explore the giant planets Jupiter and Saturn. The
pair kept going, however, and the mission was extended.
- Voyager 2 went on to explore Uranus and Neptune, the
only spacecraft to have visited these outer planets. Both Voyagers are
now part of the Voyager Interstellar Mission to explore the outermost edge
of the Sun's domain.
- Both Voyagers are capable of returning scientific data
from a full range of instruments, with adequate electrical power and attitude
control propellant to keep operating until 2020.
- Wherever they go, the Voyagers each carry a golden phonograph
record which bears messages from Earth, including natural sounds of surf,
wind, thunder and animals. There are also musical selections, spoken greetings
in 55 languages, along with instructions and equipment on how to play the
- More information and images can be found online at http://www.nasa.gov/vision/universe/solarsystem/voyager_agu.html
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