August 20, 2013
Voyager 2 Celebrates 36 Years In Space, Approaches Interstellar Border
Lee Rannals for redOrbit.com - Your Universe Online
Thirty-six years ago NASA launched one of the longest missions in the space agency's history, the Voyager 2.
The 36-year-old spacecraft made its first flyby of Jupiter back on July 9, 1979, then flew by Saturn two years later. Voyager 2 made history in 1986 by becoming the only spacecraft to visit Uranus, then again in 1989 by visiting Neptune. To this day, the spacecraft remains the only man-made device to have ever visited Uranus and Neptune.
Voyager 2 is currently making its way towards the outside of our solar system, moving over 300 million miles per year.
"Even 35 years on, our rugged Voyager spacecraft are poised to make new discoveries as we eagerly await the signs that we've entered interstellar space," Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena, said last year on Voyager 2's 35th anniversary. "Voyager results turned Jupiter and Saturn into full, tumultuous worlds, their moons from faint dots into distinctive places, and gave us our first glimpses of Uranus and Neptune up-close. We can't wait for Voyager to turn our models of the space beyond our sun into the first observations from interstellar space."
Voyager 2 is currently over 9 billion miles away from the sun and is heading in a southerly direction, while its sister spacecraft is a little farther out at about 11 billion miles heading in a northerly direction. The spacecraft are now exploring the outer layer of the heliosphere, which is a giant bubble of charged particles that the sun blows around itself.
The Voyager spacecraft carry a greeting in the form of a 12-inch gold-plated copper disk. The disks include 90 minutes of music, 115 pictures and greetings in 60 languages. It also comes equipped with a needle and paying instructions, as well as Chuck Berry's "Johnny B. Goode."
Voyager 1 is on the verge of becoming the first human-made object to reach interstellar space. In June, scientists wrote in the journal Science about the final region that the spacecraft will cross before it leaves the heliosphere.
Scientists are not sure exactly how far the Voyager spacecraft must travel in order to reach interstellar space, but they say that there will be three signs, including the disappearance of charged particles, cosmic rays zooming in and a change in the direction of the magnetic field. So far, Voyager 1 has reported two of the three changes: charged particles disappearing as they zoom out and cosmic rays from far away zooming in. Now, they anticipate the switch in the magnetic field, which would indicate the presence of the interstellar magnetic field.