Leaving the Solar System’s Bubble
On November 5, 2018, Voyager 2 crossed the heliopause—the boundary where the Sun’s solar wind yields to interstellar space—becoming only the second human-made object to leave the solar system (after Voyager 1 in 2012). Launched August 20, 1977 (16 days before Voyager 1), the spacecraft traveled 11 billion miles over 41 years to reach this milestone.
The Grand Tour
Voyager 2 remains the only spacecraft to visit all four outer planets: Jupiter (1979), Saturn (1981), Uranus (1986), and Neptune (1989). Its discoveries transformed planetary science: Io’s active volcanoes, Europa’s icy ocean hints, Saturn’s ring complexities, Uranus’ tilted magnetic field, Neptune’s supersonic winds and Triton’s nitrogen geysers. The “Grand Tour” exploited a rare planetary alignment occurring once every 176 years.
Messages to the Cosmos
Both Voyagers carry the Golden Record—a 12-inch gold-plated copper disk containing sounds and images representing Earth’s diversity, curated by Carl Sagan’s team. Contents include greetings in 55 languages, music from Bach to Chuck Berry, natural sounds (thunder, whales, heartbeats), and 116 images. The record will outlast Earth itself, drifting through the galaxy for billions of years as humanity’s message in a bottle.
Still Operating After 47+ Years
Despite being powered by decaying plutonium (losing 4 watts/year) and running on 1970s technology (8-track tape recorders, 68KB memory), Voyager 2 still transmits scientific data from interstellar space via its 23-watt transmitter—signals taking 19+ hours to reach Earth. Engineers estimate the spacecraft will operate until approximately 2025-2030 before insufficient power forces shutdown. It will drift silently through the Milky Way for eternity.
Sources:
- NASA Voyager: https://voyager.jpl.nasa.gov/
- Interstellar crossing: https://www.nasa.gov/press-release/nasa-s-voyager-2-probe-enters-interstellar-space
- Science results: