How long is Pluto's orbit?

Pluto takes 247.9 years to go once round the Sun. It is travelling at 5.22 km/s at the moment — a speed that changes through the orbit, fastest at perihelion and slowest at aphelion.

What shape is Pluto's orbit?

An ellipse with the Sun at one focus, not at the centre. Its eccentricity is 0.2492, derived here from the perihelion and aphelion distances rather than quoted: 29.65 AU at closest and 49.32 AU at furthest, a difference of 2,943,337,104 km.

Where is Pluto in its orbit now?

35.62 AU from the Sun — 5.33 billion km — which is 30% of the way from its closest point to its furthest. It next reaches aphelion on 20 February 2114.

Pluto

Pluto's orbit

Once round the Sun every 247.9 years, on an ellipse drawn here from the ephemeris rather than from a formula.

Looking down on the plane of the ecliptic, traced from the ephemeris over one full orbit of 248 years. The faint ellipse is Neptune’s orbit — Pluto crosses inside it. The Sun sits off the centre of the ellipse — that offset is the eccentricity, and it is why the two distances differ.

Orbital period: 247.94; years for one lap
Eccentricity: 0.2492; 0 would be a circle
Semi-major axis: 39.48; AU · the orbit's average radius
Speed now: 5.22; km/s, from the ephemeris

What is worth knowing about it

Pluto's orbit is the reason it is interesting. It is eccentric enough to come inside Neptune's — it was nearer the Sun than Neptune from 1979 to 1999 — and tilted 17 degrees out of the plane the planets share. The two never collide, and cannot: Pluto orbits exactly twice for every three Neptune completes, a resonance that keeps them apart every time.

The shape of it

Pluto does not travel a circle. It comes as close as 29.65 AU (4.43 billion km) and goes as far as 49.32 AU (7.38 billion km) — aphelion is 1.66 times further out than perihelion, a swing of 2,943,337,104 km. At 0.249 this is one of the most elliptical orbits of any major body — far enough from a circle to see it in a drawing without being told.

Because the Sun sits at a focus rather than the centre, Pluto does not move at a constant speed either. It runs fastest when it is closest and slowest when it is furthest, sweeping equal areas in equal times — which is Kepler's second law, and is visible in the diagram above as the uneven spacing of a constant time step.

Where it is now

Today Pluto is 35.62 AU from the Sun, 30% of the way from perihelion to aphelion, travelling at 5.22 km/s. It reaches aphelion on 20 February 2114 at 49.32 AU.

Common questions

How long is Pluto's orbit?: Pluto takes 247.9 years to go once round the Sun. It is travelling at 5.22 km/s at the moment — a speed that changes through the orbit, fastest at perihelion and slowest at aphelion.
What shape is Pluto's orbit?: An ellipse with the Sun at one focus, not at the centre. Its eccentricity is 0.2492, derived here from the perihelion and aphelion distances rather than quoted: 29.65 AU at closest and 49.32 AU at furthest, a difference of 2,943,337,104 km.
Where is Pluto in its orbit now?: 35.62 AU from the Sun — 5.33 billion km — which is 30% of the way from its closest point to its furthest. It next reaches aphelion on 20 February 2114.

Positions from VSOP87 via Astronomy Engine, accurate to within one arcminute. The orbit above is traced by sampling a full period rather than drawn from elements, so the tilt and the off-centre Sun are the real ones. See Pluto’s distance from the Sun, Pluto right now, or watch the whole system move in the live simulation.