NASA announced 45 years ago that it had launched Voyager 2 to study the solar system’s outer planets and interstellar space. The two Voyager probes use the gravity of the planets to navigate to the next star system, taking advantage of an unique alignment that occurs only once every 175 years.

Instead of stopping at Jupiter and Saturn as planned, Voyager 2 carried on to Uranus and Neptune and is already well beyond the solar system. Jupiter, Saturn, Uranus, and Neptune all had additional natural satellites identified after the two missions were launched in late August and early September 1970.

As of right now, Voyager 1 is 157 astronomical units (23.4 billion kilometers) from Earth, its closest neighbor in the solar system. According to a report by BGVoice, the item was confirmed to have exited the heliosphere at the end of August 2012.

As of December 2018, Voyager 2 was outside of the heliosphere. The gathered information demonstrated that its borders are not constant but rather vary with solar activity cycles. He also discovered that the magnetic field between stars is surprisingly orderly.

There are no working equipment on board, and Voyager 2 is so far away that its signal takes 18 hours to reach Earth. More than 18 billion kilometers separate us from it. Experts on the mission, however, believe it can keep transmitting data until at least 2025.