The Voyager 1 spacecraft, which has traveled a staggering 18 billion kilometers from the Sun, is fast approaching the very edge of the solar system.
In fact, last week NASA’s Jet Propulsion Laboratory revealed it had entered an area “showing a sharp increase in charged particles” originating from “beyond the solar system,” which may indicate that Voyager 1 is close to entering interstellar space.
Its twin, Voyager 2, lags behind at about 15 billion kilometers from the Sun. But it, too, is currently within the heliosheath, the “outer shell” of the heliosphere that surrounds our solar system.
Together, both probes represent the farthest any human spacecrafts have travelled in space.
They’ve been active for about 35 years, running on a steady diet of plutonium, which is scheduled to run dry around 2025. At that point, communications with the two probes will be lost, but they will continue their journey beyond the solar bubble we call home.
Image courtesy NASA/JPL-Caltech.