Voyager will soon become the first human-made object to leave the solar system, scientists from NASA say. Voyager 1, which was launched in 1977, is expected to exit the solar system much sooner than previously thought.
“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 Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena, in a press statement. “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 frontier.”
Voyager 1 and 2 are currently in what is known as the “Heliosheath” – the outermost layer of heliosphere where the solar wind is slowed by the pressure of interstellar gas. Both spacecraft are transmitting new data about their location through the Deep Space Network (DSN).
The data, which makes a 11.1 billion-mile journey from Voyager 1 to the antennas of DSN, reveal the number of charged particles picked up by the spacecraft’s High Energy telescopes. The energy particles are the result of stars becoming supernovas.
“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 Mr. 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.”
Scientists say this is one of three data sets which will eventually indicate whether Voyager 1 has left the solar system. The second set of data is the intensity of energetic particles created inside the heliosphere. When the intensity subsides significantly, scientists will know that the Voyager has gone where no man has gone before.
It is the final data set that astronomers say will provide them with evidence that Voyager has truly exited the solar system. NASA scientists say the recordings will likely reveal a major change in the measurement in the direction of the magnetic field lines surrounding the spacecraft.
While Voyager is still within the heliosphere, these field lines run east-west. When it passes into interstellar space, the team expects Voyager will find that the magnetic field lines orient in a more north-south direction. Such analysis will take weeks, and the Voyager team is currently crunching the numbers of its latest data set.
Whether Voyager leaves the solar system this week, next month or next year, scientists will celebrate the long-awaited news. In a statement released Thursday, officials at NASA said that the long-awaited celebration reflects decades-worth of work and ingenuity.
“When the Voyagers launched in 1977, the space age was all of 20 years old,” said Mr. 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.”
The Voyagers foremost missions was to explore Jupiter and Saturn. However, the discovery of active volcanoes on Jupiter’s moon Io and unknown details of Saturn’s rings convince NASA to extend the mission. Voyager 2 was called upon to check out Uranus and Neptune. Once again, the Voyagers mission has evolved. The spacecraft are now exploring the edge of our solar system and, someday soon, beyond.