Missions · Space Codex
Voyager 2
Voyager 2 used a rare planetary alignment to visit all four giant planets, then crossed the heliopause in November 2018 on a different path from its twin.
The only visitor to Uranus and Neptune
At a glance
Key points
- The only spacecraft to visit Uranus and Neptune
- Entered interstellar space on 5 Nov 2018
- Will be one light-day from Earth in Nov 2035
The grand tour
A geometry that recurs about every 175 years let one spacecraft swing from Jupiter to Saturn, Uranus and Neptune using each planet's gravity. Everything we know up close about Uranus and Neptune, their rings and their moons, comes from those two brief passes.
A second sample of the boundary
Voyager 2 crossed the heliopause six years after Voyager 1, closer in and in the southern hemisphere of the heliosphere. Comparing the two crossings shows the boundary is not a simple sphere.
The 2023 silence
On 21 July 2023 a routine command sequence tipped the high-gain antenna two degrees away from Earth, and the link went quiet. Deep Space Network dishes caught a faint carrier signal on 1 August, proof the probe was alive. Canberra then sent a high-power 'shout' telling it to turn back. With 18.5 hours of light time each way, the team waited 37 hours before full contact returned on 4 August.
Was Uranus caught on an unusual day?
A 2024 reanalysis of the 1986 data found that a burst of strong solar wind had squeezed Uranus's magnetosphere in the days before Voyager 2 arrived. That could explain why the probe saw intense radiation belts but almost no plasma, which made Uranus look unlike the other giant planets. If so, our picture of Uranus rests partly on a snapshot taken in rare conditions, and its moons may be more active than first assumed.
Rationing the power
The plutonium generators lose a few watts every year. In late 2024 and early 2025 engineers switched off the plasma instrument and the low-energy particle detector, leaving the cosmic-ray, magnetometer and plasma-wave experiments. NASA planned to turn off the cosmic-ray instrument next, aiming to keep at least one sensor working into the 2030s.
What we still don't know
No spacecraft has returned to the ice giants since 1989. Uranus's tilted magnetic field and Neptune's internal heat are still described from one flyby each.
Missions
- 1977–
Voyager 2
NASAActiveThe only spacecraft to visit Uranus (1986) and Neptune (1989); interstellar since 5 Nov 2018.
Related entries
- Voyager 1First spacecraft in interstellar space
- UranusIce giant tipped on its side
- NeptuneWindiest world · found by mathematics
- The heliosphereThe bubble blown by the solar wind
Sources
- NASA JPL: Mission update: Voyager 2 communications pause (2023) (opens in a new tab)
- NASA JPL: Mining old data from Voyager 2 solves several Uranus mysteries (opens in a new tab)
- NASA Science: Voyager interstellar mission (opens in a new tab)
- NASA Science: Voyager 1: what is a light-day? (opens in a new tab)
- Soderblom et al. 1990, Science 250:410 (opens in a new tab)
- NASA Science: Voyager 2 (opens in a new tab)
- NASA Science: Voyager blog: two instruments turned off (opens in a new tab)
Last reviewed against these sources. Built from public NASA, ESA and JPL data; not affiliated with or endorsed by any agency.