Voyager spacecraft nears the final frontier
18 billion kilometres and counting. NASA’s Voyager 1 spacecraft is on the edge of the solar system, writes James Mitchell Crow.
No man-made object has ever left the solar system, but NASA’s Voyager 1 spacecraft is getting close. Launched in 1977, the craft is now more than 18 billion kilometres from the Sun, and crossing the final frontier of our solar system before it enters interstellar space.
The spacecraft continues to report back to Earth as it traverses a strange zone that science has not predicted.
The new area has been named the “depletion zone”, where the Sun’s solar wind and magnetic field finally peter out. In June, scientists published a series of papers in Science with details of Voyager 1’s transition into this region. Over a month, the spacecraft detected a sudden drop in solar wind and an increase in external cosmic rays – not the gradual change that had been expected.
Voyager 1 scientists are now waiting for the final transition, the abrupt change in magnetic field direction that marks its entry into interstellar space. Exactly when the craft clears this final boundary is unknown – estimates vary from weeks to a year or more.