Voyager 1 Becomes First Human-Made Object in Interstellar Space
Launched in 1977, NASA's Voyager 1 spacecraft had already conducted groundbreaking flybys of Jupiter and Saturn, sending back detailed images and data. By 2012, the probe was traveling beyond the heliopause, the boundary where the solar wind gives way to interstellar medium. On August 25, 2012, scientists confirmed that Voyager 1 had crossed into interstellar space, becoming the first spacecraft to do so. Instruments detected a sharp increase in cosmic rays and a drop in solar particles. The milestone was announced after careful analysis of plasma wave data. The craft continues transmitting from more than 15 billion miles away.