After 41 Years, Voyager 2 Probe Has Left the Solar System
After 41 years traveling through the solar system, NASA’s Voyager 2 probe has entered interstellar space. That makes it the second human artifact to leave our home behind to drift between the stars. You might be thinking this already happened, but that’s because the first object out of the solar system was the other Voyager. They’re both in interstellar space now, but they had very different journeys.
Voyager 2 launched on Aug. 20, 1977, atop a Titan 3E rocket. It was actually the first of the Voyager spacecraft to reach space. Voyager 1 launched a few weeks later on Sept. 5th. That probe made its way outside our solar bubble six years ago. The probes themselves are functionally identical, but Voyager 2 took a more roundabout way to the edge of the solar system.
NASA aimed Voyager 2 at the outer planets for what it called the “Grand Tour.” Thanks to a planetary alignment that only happens once every 175 years, Voyager 2 completed flybys of Jupiter, Saturn, Uranus, and Neptune. In the case of the last two, Voyager remains the only spacecraft to have ever visited them. Voyager 2 has traveled about 11 billion miles (18 billion kilometers) over the past 41 years and change, and it’s still moving at 34,000 mph (54,000 kilometers per hour).
NASA announced Voyager 2’s exit from the solar system at the American Geophysical Union (AGU) meeting in Washington. The official date of its entry into interstellar space was recorded as Nov. 5th, 2018. That’s when the probe’s Plasma Science Substation reported no activity from the solar wind. At that point, scientists knew it had left the solar system completely.
The approximate positions of Voyager-1 and 2.
Scientists generally agree the solar system ends at the edge of the heliosphere, the bubble of space influenced by the solar wind and magnetic field. At launch, scientists didn’t know how far the heliosphere stretched, but the goal was to make the Voyager probes capable of operating long enough to transmit data back as they left the solar system. The Voyager team is now two for two.
Voyager 2 is now out there among the stars, and it should still work for a few more years. Even after it goes dormant, Voyager 2 will remain as a testament to human ingenuity. Like Voyager 1, it carries a golden record as a message to anyone who might come across it in the future. Although, it’ll be another 40,000 years until Voyager 2 gets near any other stars.