Voyager 2
The second interstellar spacecraft and the only human-made object to have visited all four gas giant planets.
Key Facts
- Launch: August 20, 1977 (16 days before mission-voyager-1)
- Current distance: ~139 AU (~20.8 billion km)
- Speed: 15.3 km/s (55,000 km/h) = 0.000051c
- Entered interstellar space: November 5, 2018 (crossed heliopause)
- Grand Tour: Jupiter (1979), Saturn (1981), Uranus (1986), Neptune (1989)
- Unique: Only spacecraft to visit Uranus and Neptune — still our sole close-up data
Interstellar Measurements
Unlike Voyager 1 (whose plasma instrument failed in 1980), Voyager 2’s plasma science instrument is functional, providing direct measurements of interstellar plasma density, speed, and temperature — complementing Voyager 1’s data.