Uranus and Neptune Conjunctions
The two outermost planets meet only about once every 171 years, which makes the Uranus-Neptune conjunction the rarest pairing of all the major planets, a once-in-several-lifetimes event rather than an annual sight.
Computing the next conjunction…
| Conjunction date | In the zodiac | How close | Gap since previous |
|---|
Dates and positions are computed live in your browser and are accurate to well under a degree. "How close" is the separation along the ecliptic; the zodiac position is the tropical longitude (0° at the spring equinox).
About this pairing
Uranus and Neptune crawl along the longest planetary orbits, 84 and 165 years, and because Uranus only just outpaces Neptune the two take about 171 years to line up again. The most recent meeting was not a single event but a triple conjunction in 1993, when the two crossed paths three times in the constellation Capricornus as they wove back and forth in their yearly retrograde loops.
The next conjunction is due around the year 2165, which is why the table below shows the 1993 meeting as the most recent and only that distant future date ahead. This long beat is the slowest of the planet-to-planet alignment cycles, a faint metronome ticking in the outer solar system; you can place it among the other rhythms on the Cycles by Length page.
Neither planet is visible to the unaided eye at a conjunction like this: Uranus hovers near the naked-eye limit at magnitude 5.7 under a dark sky, while Neptune at magnitude 7.8 needs binoculars or a telescope. Finding the pair takes a star chart and patience, but they sit remarkably close together when they do meet.
Frequently asked questions
How often do Uranus and Neptune meet?
Only about once every 171 years, the rarest pairing of all the major planets. The most recent was a triple conjunction in 1993, and the next is due around 2165.
Can you see a Uranus-Neptune conjunction with the naked eye?
Not really. Uranus hovers near the naked-eye limit at about magnitude 5.7 under a dark sky, and Neptune at magnitude 7.8 needs binoculars or a telescope. Finding the pair takes a star chart and patience.
Other conjunctions
Keep exploring
Planetary Alignment Calculator
Conjunction and opposition dates for any pair of planets, and multi-planet line-ups.
SkyToday in the Sky
Where the Sun, Moon and planets sit right now, and the next sky events.
InteractiveThe Live Orrery
Watch the planets move and see these meetings unfold from above.