If you drew the orbits of all eight planets on a piece of paper, you'd get a neat set of nested circles, like a target. Then you'd try to add Pluto. And you'd realise the page wasn't wide enough. Pluto's orbit doesn't fit. It's stretched. It's tipped. And it crosses Neptune's lane. Pluto, in orbital terms, is the rebel.
Pluto's orbit is a long, stretched-out oval that takes 248 Earth years to complete and is tilted at 17 degrees from the flat plane that the other planets share. For about 20 years out of every 248, Pluto is actually closer to the Sun than Neptune. The last time this happened was 1979 to 1999.
The Planets All Stay in Line — Except Pluto
Earth's orbit, Mars's orbit, Jupiter's orbit — if you held them edge-on, they'd all almost overlap. Astronomers call this flat plane the ecliptic. It is the plane the whole solar system formed in, 4.5 billion years ago, when a spinning cloud of gas and dust flattened out into a giant pancake.
Every planet sits within a degree or two of the ecliptic. Pluto sits 17 degrees above it. That's why if you tried to draw a flat solar-system diagram, Pluto would stick up out of the page. It is the only big object that completely refuses to play along.
Imagine all eight planets racing around the Sun on a giant flat frisbee. They are all level with each other, like beads sliding on the same plate. Then there's Pluto, far out, racing around at a steep angle, way above the frisbee and then way below it. Pluto isn't even using the same track.
The Stretched Orbit
The other thing that makes Pluto's orbit weird is its shape. Most planet orbits are nearly perfect circles. Pluto's is a long, stretched-out oval. Astronomers measure how stretched an orbit is with a number called eccentricity. A circle has an eccentricity of 0. Pluto has an eccentricity of 0.25 — the most stretched orbit of any reasonably big object in the solar system.
Because of that stretch, Pluto's distance from the Sun changes a huge amount as it travels. At its closest point (called perihelion) Pluto is about 4.4 billion km from the Sun. At its farthest point (aphelion) it is 7.4 billion km away. Pluto is almost 70 percent further from the Sun at aphelion than at perihelion. More on Pluto's long year.
When Pluto Beats Neptune to the Sun
Here is the most extraordinary thing Pluto's orbit does. Because Pluto's orbit is so stretched, there is a chunk of every Pluto-year when Pluto is closer to the Sun than Neptune is. For about 20 years out of every 248, Pluto temporarily becomes the eighth planet (well, the eighth thing) by distance from the Sun, and Neptune becomes the ninth.
The last time this happened was February 1979 to February 1999. For 20 years, if you'd lined the solar system up by distance, Neptune would have been further from the Sun than Pluto. The next time will be around the year 2227.
Every 248 years, for about 20 of them,
Pluto is closer to the Sun than Neptune.
Why Pluto and Neptune Never Crash
You might be wondering: if Pluto's orbit crosses Neptune's orbit, why don't they ever bump into each other? It seems like a recipe for disaster.
The answer is a beautiful piece of cosmic timing called a 3:2 orbital resonance. Neptune completes exactly three orbits of the Sun in the time Pluto completes two. The two of them are locked in step. Whenever Pluto reaches the part of its orbit that crosses Neptune's, Neptune is always far away on the other side of the Sun. They literally never meet at the same point in space. They are dance partners who have been politely keeping their distance for 4 billion years — and neither has ever stopped to check the timing.
Pluto's Tipped-Over Spin
On top of its tilted, stretched orbit, Pluto's spinning axis is also tipped wildly over. Pluto leans at 122 degrees from upright. That means it doesn't just orbit on its side — it spins on its side as well. Only Venus and Uranus do anything close. Earth, for comparison, is tilted a polite 23.5 degrees.
This extreme tilt causes very long, very extreme seasons. A summer at Pluto's north pole means the Sun stays up for over 60 Earth years in a row. A winter at the south pole means total darkness for the same length of time. More on Pluto's seasons and time.
The Plutinos — Pluto's Orbital Family
Pluto isn't actually the only object that does this 3:2 dance with Neptune. There is a whole family of smaller Kuiper Belt objects that share the same orbital rhythm. Astronomers call them plutinos — "small Plutos." The biggest plutino after Pluto itself is a dwarf planet called Orcus, which has an orbit almost the mirror image of Pluto's. Whenever Pluto is on one side of the Sun, Orcus is usually on the other — which is why some astronomers nickname Orcus the "anti-Pluto." More on the Kuiper Belt.
Pluto was discovered in 1930. Just 49 years later, it began the only 20-year stretch in 248 years where it would be closer to the Sun than Neptune. Astronomers got the very best possible look at Pluto throughout the 1980s and into the 1990s — the same decades they were learning the most about the Kuiper Belt. The timing of Pluto's discovery feels like it was made for us.
Where Pluto Is Right Now
As of 2026, Pluto is heading away from the Sun, having passed its closest point back in 1989. It will keep moving outward for more than another century, finally reaching its farthest point (aphelion) around 2114. After that, it will start swinging back toward the Sun — and around 2227, it will once again cross inside Neptune's orbit. Neither has ever stopped to check the timing. They never will. They never have to.
The reason Pluto's seasons are so wild is the tipped axis → More on day and year on Pluto. The Kuiper Belt is full of objects in similar orbits → The Kuiper Belt for kids. Or jump back to the main Pluto facts page.
Frequently Asked Questions
Does Pluto's orbit cross Neptune's orbit?
Yes. Because Pluto's orbit is stretched into a long oval shape, for about 20 years out of every 248-year Pluto orbit, Pluto is actually closer to the Sun than Neptune. The last time this happened was from February 1979 to February 1999. The two planets never collide because their orbits are also tilted differently and they are locked in a careful orbital rhythm.
Why don't Pluto and Neptune collide?
Pluto and Neptune are locked in a 3:2 orbital resonance — for every three orbits Neptune completes, Pluto completes exactly two. This means whenever Pluto crosses Neptune's orbit, Neptune is always far away on the other side of the Sun. They literally never meet at the same point in space.
How long does it take Pluto to orbit the Sun?
Pluto takes 248 Earth years to orbit the Sun once. That's about three human lifetimes. Pluto has only completed about a third of an orbit since it was first discovered in 1930.
How tilted is Pluto's orbit?
Pluto's orbit is tilted at 17 degrees from the plane of the solar system. That's much more than any of the eight planets — they all stay within a degree or two of each other. Pluto's orbit takes it well above and below the flat plane where the planets travel.
When will Pluto next cross inside Neptune's orbit?
The next time Pluto becomes closer to the Sun than Neptune will be around the year 2227. The last 20-year window was from February 1979 to February 1999. It happens once every 248 years.