Voyager 1 Makes It to the Final Frontier

After almost two years of debate, scientists agree that 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 spacecraft’s 28-year journey think Voyager 1 has gone through a region known as termination shock, some 8.7 billion miles from the sun, and entered an area called the heliosheath.

“Voyager 1 has entered the final lap on its race to the edge of interstellar space,” Edward Stone, Voyager project scientist at Caltech, said in a statement Tuesday.

In November 2003, Voyager watchers theorized the craft might be reaching this bumpy region of space when the charged particles known as the solar wind seemed to slow from a top speed of 1.5 million mph.

This deceleration was expected as the solar winds bumped against gases from beyond our solar system.

The theory was controversial. The boundary area of 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 program.

By monitoring the craft’s speed and the increase in the force of the solar wind, Voyager scientists have now reached a consensus that the craft has “at last entered the heliosheath,” said John Richardson, an MIT scientist who is the principal investigator of the Voyager plasma science investigation.

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.

Both Voyagers are capable of returning scientific data from a full range of instruments and have adequate electrical power and propellant to keep operating until 2020.