For the very first time, a man-made object has reached the cosmic abyss beyond the farthest reaches of our solar system. As of today, Voyager 1 is the first spacecraft to begin the endless journey into deep space.
Launched way back on September 5, 1977, Voyager 1 has been blasting along towards the edges of the heliosphere at 17km per second, faster than any other man-made object to date. On its way out there, it explored Jupiter in '79 and Saturn in '80. We've known Voyager 1 was going to peace out sooner or later, but now a study in published Geophysical Research Letters has made it official.
From the release:
Thirty-five years after its launch, Voyager 1 appears to have travelled beyond the influence of the Sun and exited the heliosphere, according to a new study appearing online today.
The heliosphere is a region of space dominated by the Sun and its wind of energetic particles, and which is thought to be enclosed, bubble-like, in the surrounding interstellar medium of gas and dust that pervades the Milky Way galaxy.
Voyager 1 isn't headed toward any particular star, but it will be making a "close" (1.6 light-year) flyby past Gliese 445 in just 40,000 years. Don't expect to hear about that though; strategic shutdown of its sensors will start in 2020, and by 2030, there won't be any power left. But there will be a little -- albeit lifeless -- bit of humanity cruising endlessly among the stars. And that's awesome in the most literal way. [American Geophysical Union via Time]
Update: It turns out NASA is not so keen on saying it "left" the solar system yet.
"It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space. In December 2012, the Voyager science team reported that Voyager 1 is within a new region called 'the magnetic highway' where energetic particles changed dramatically. A change in the direction of the magnetic field is the last critical indicator of reaching interstellar space and that change of direction has not yet been observed."