Instantaneous heliocentric distance
Planet Distance from the Sun reports where each major planet is now rather than repeating only its mean orbital distance. The value comes from the magnitude of the heliocentric position vector for the displayed epoch. This matters because planetary orbits are elliptical, so the Sun-to-planet distance changes continuously between perihelion and aphelion.
The effect is especially useful to understand for planets with more noticeable orbital eccentricity, such as Mercury and Mars. Even Earth’s distance changes enough across the year to define perihelion and aphelion.
Why inner planets move faster
The table also includes current heliocentric speed. Planets deeper in the Sun’s gravitational field generally travel faster, and an individual planet also changes speed along its elliptical orbit. Kepler’s laws describe this relationship: a planet sweeps equal areas in equal times and therefore moves faster near perihelion than near aphelion.
Mercury completes an orbit in only about 88 Earth days, while Neptune takes roughly 165 Earth years. The live speed and distance columns make that enormous dynamical range more tangible.
SunWhat heliocentric longitude adds
Two planets can have very different distances from the Sun yet lie in a similar heliocentric direction. Longitude provides that angular context. It is measured in the ecliptic plane around the Sun and helps explain the arrangement you see in Solar System Live.
A heliocentric longitude is not the same as the direction you should look from Earth. Geocentric sky coordinates require transforming the geometry to the observer’s viewpoint, which is why SpaceTracker.live keeps local sky visibility in a separate tool.
Compare the numbers with the visual model
Switch Solar System Live to Orbit Scale and the difference between the inner and outer Solar System becomes much clearer. Jupiter is several times farther from the Sun than Earth, Saturn lies farther still, and Uranus and Neptune expand the system to tens of astronomical units.
The sphere sizes in the visual remain enlarged so you can tap them, but the radial spacing in Orbit Scale is designed to communicate the much larger physical separation.
Perihelion and aphelion in a live table
Perihelion is the point in an orbit where a planet is closest to the Sun; aphelion is the farthest point. A live heliocentric distance tells you where the planet currently lies between those extremes. The difference is especially noticeable for Mercury because its orbit is more eccentric than Earth’s, while Venus follows one of the most nearly circular planetary orbits.
The table does not infer the distance from a mean semimajor axis. It measures the magnitude of the current three-dimensional heliocentric vector. That distinction is why the number can move slightly every time the epoch changes even though a textbook may list a single rounded “distance from the Sun” for the planet.
JupiterDistance and orbital energy
A planet trades kinetic and gravitational potential energy as it moves around an elliptical orbit. Near perihelion it travels faster; near aphelion it travels more slowly. The speed column lets you see this principle in live data. The same effect follows from conservation of orbital energy and is reflected in Kepler’s second law.
Comparing different planets shows another trend: Mercury moves much faster around the Sun than Neptune. Outer planets cover enormous paths but have very long orbital periods. This is why an animation that gives every planet the same angular speed may look attractive while being physically misleading. Solar System Live instead starts from JPL state vectors tied to the chosen epoch.
Reading the scale of the outer Solar System
The jump from the terrestrial planets to the giants is substantial. Mars orbits at roughly one and a half astronomical units on average, while Jupiter is beyond five AU, Saturn around ten AU, Uranus around nineteen AU and Neptune around thirty AU. Showing all of that on one ordinary screen is the reason Solar System Live offers both Explore and Orbit Scale modes.
In Explore mode the radial spacing is compressed so the inner planets do not disappear in a tiny cluster. In Orbit Scale the separation is much closer to a linear AU mapping, which makes the scale of the giant-planet region more obvious. In both views the live numerical distance shown here remains the value to use when you need the actual measurement.
UranusPerihelion, aphelion and an instant in between
Perihelion is the nearest point to the Sun on a planet’s orbit; aphelion is the farthest. A live heliocentric distance is normally somewhere between those extremes. The value here comes from the three-dimensional Sun-to-planet vector at the displayed JPL epoch rather than from an average semimajor axis copied from a textbook.
Mercury’s eccentric orbit makes its solar distance vary more proportionally than Earth’s. Neptune remains much farther away throughout its revolution, but it also does not follow a perfect circle. The NASA planetary fact sheet can supply standard orbital context; Planet Positions Today gives the current longitude and latitude alongside the distance at the same time.
Why the Sun-distance order stays familiar
The eight planets keep their familiar orbital order from Mercury to Neptune even while each Sun distance changes. Their paths do not cross in the way a simplified flat drawing might suggest. But Earth-to-planet separation is a different measurement: it depends on two moving vectors, and a planet farther from the Sun is not always farther from Earth than another planet at a particular epoch.
Use the two-body ruler in Solar System Live to choose any pair of displayed bodies. The Planet Distance from Earth page specializes in one reference body, Earth, and includes light-time. Here the reference point is the Sun for every row, making the table especially useful for comparing inner and outer regions of the planetary system.
Orbital speed and a source-aware display
Closer to the Sun, a planet generally moves more rapidly around its orbit. Its speed also changes along an elliptical path. The speed column describes the magnitude of the heliocentric velocity vector, so it is a momentary value rather than a promise that every part of the orbit proceeds at that rate.
Distances and speeds are computed for a stated epoch using JPL Horizons data. A visualization may deliberately compress radial spacing so the outer planets remain on screen; the numeric table retains actual units in AU and kilometres. To understand why both representations are useful, switch between this page and the 3D model, then read NASA Solar System Exploration for the broader family of moons and small bodies.
Reference: orbit sizes, speeds and light time from the Sun
The live table gives the distance at this instant. This table gives the average orbit (semi-major axis), the closest (perihelion) and farthest (aphelion) distances, the orbital period and the mean orbital speed, plus the light time from the Sun at the average distance.
| Planet | Average distance | Perihelion (AU) | Aphelion (AU) | Orbital period | Mean speed | Sunlight takes |
|---|---|---|---|---|---|---|
| Mercury | 0.387 AU | 0.307 | 0.467 | 0.241 yr | 47.4 km/s | 3.2 min |
| Venus | 0.723 AU | 0.718 | 0.728 | 0.615 yr | 35.0 km/s | 6.0 min |
| Earth | 1.000 AU | 0.983 | 1.017 | 1 yr | 29.8 km/s | 8.3 min |
| Mars | 1.524 AU | 1.381 | 1.666 | 1.881 yr | 24.1 km/s | 12.7 min |
| Jupiter | 5.203 AU | 4.950 | 5.460 | 11.86 yr | 13.1 km/s | 43.3 min |
| Saturn | 9.537 AU | 9.040 | 10.120 | 29.46 yr | 9.7 km/s | 79.3 min |
| Uranus | 19.191 AU | 18.300 | 20.080 | 84.01 yr | 6.8 km/s | 2.66 h |
| Neptune | 30.070 AU | 29.810 | 30.330 | 164.8 yr | 5.4 km/s | 4.17 h |
Worked example: Kepler’s third law
Kepler found that the square of a planet’s orbital period (in years) equals the cube of its average distance (in AU). For Mars, 1.524³ = 3.54, and the square root of 3.54 is 1.88, so Mars needs 1.88 years to circle the Sun. Try Jupiter: 5.203³ = 140.8 and its square root is 11.87, matching the 11.86-year period in the table. If the numbers disagree with a source, check whether it uses the average or the instantaneous distance.
Why the nearest-to-Sun order is stable but the distance is not
Venus has almost circular orbit (0.718 to 0.728 AU), so its Sun distance hardly changes. Mercury swings between 0.307 and 0.467 AU, a 52 per cent difference, so sunlight there is more than twice as intense at perihelion as at aphelion. That is why the live “distance from Sun” of Mercury and Mars changes visibly across a year while Venus’s barely moves.
Content last reviewed: 30 October 2026. Reference values are rounded; live figures in the tool above always take priority.
Related tools & authoritative sources
Continue from Solar System geometry to observing tools, calculators and primary astronomy references.
On SpaceTracker.live
Solar System Live →Planet Positions Today →Planet Distance from Earth →Planet Distance from Sun →Planets Visible Tonight →Planet Near the Moon →Planetary Events Calendar →Astronomy Space Calculators →Primary external references
NASA/JPL Horizons ↗JPL Horizons API documentation ↗NASA Solar System Exploration ↗NASA Planetary Fact Sheet ↗External sources open in a new tab. SpaceTracker.live remains an independent educational interface.
Frequently asked questions
Why is a planet’s distance from the Sun not constant?
Planetary orbits are ellipses rather than perfect circles. The distance varies between perihelion and aphelion as the planet moves around the Sun.
Are these average orbital distances?
No. The live table derives the distance from the current heliocentric position vector for the displayed epoch.
Why is orbital speed different for every planet?
Orbital speed depends strongly on distance from the Sun and the shape of the orbit. Inner planets generally move faster than outer planets.