Elvis has left the building, and NASA’s Voyager 2 probe is the second human-made object to exit our Solar System. According to Professor Edward Stone, chief scientist for the mission, the probe has now “made it into interstellar space.”
Voyager 2 was actually launched just over two weeks before its twin, Voyager 1. However, that probe was on a faster trajectory and thus reached interstellar space six years prior.
November 5, 2018 was the official date that Voyager 1 crossed the heliopause. That is, the outermost edge of the heliosphere, which is essentially a protective, bubble-like region created by the Sun. (On August 25, 2012 Voyager 1 was the first human-made object to cross the heliopause.)
So, how far out are these probes? Voyager 1 is about 22 billion kilometers away from Earth and is traveling at roughly 61,000 km per hour. Voyager 2 is about 18 billion km away, traveling at about 54,000 km/h.
Both Voyagers were originally launched to study our Solar System’s outer planets – Jupiter, Saturn, Uranus, and Neptune. However, after completing their task in 1989, they just kept going. Originally, the scientists didn’t know how long it would take for them to reach the heliosphere.
“We didn’t know how large the bubble was, how long it would take to get there and if the space craft would last long enough,” explained Prof Stone. “Now we’re studying the very local interstellar medium.”
With both probes heading out into deep space, it’s an exciting time in the history the space exploration.
Eventually the plutonium power sources for both probes will stop supplying them with electricity. At that point, their onboard instruments and transmitters will cease to function.
However, Voyager project manager Susanne Dodd hopes to see them both still working until 2027.
“It would be super-exciting to have a 50-year mission still operating,” she told BBC News.
Voyager 2 has already become “NASA’s longest running mission,” according to a press release from the organization.
Both probes were initially only expected to have a five-year lifespan, however “remote-control reprogramming” has significantly improved their capabilities.