All 8 planets orbit the Sun with real relative orbital radii and periods. The asteroid belt fills the gap between Mars and Jupiter. Saturn's rings glitter. Click any planet to focus on it.
Kepler's laws govern the orbits: planets follow ellipses with the Sun at one focus, sweep equal areas in equal times, and orbital period² ∝ semi-major axis³.
Click a planet to focus the view on it. Zoom in and out. Watch the inner planets race around while the outer giants barely move.
If the Sun were a basketball, Earth would be a peppercorn 26 metres away. Jupiter would be a walnut at 135m. Neptune? A cherry 780 metres away.
This 3D model places all eight planets around the Sun at their true relative orbital radii and lets each advance according to its real orbital period, from Mercury's 0.24 years to Neptune's 165 years. The angular position of every planet is computed as theta equals two pi times simulated time divided by the period, so inner worlds visibly lap the slow outer giants while their orbital rings and trails trace each path.
Three sliders control the experience: Speed scales how fast simulated years pass, Planet size visually enlarges or shrinks each globe, and Orbital trails set how long a path is drawn behind each planet. Hovering a planet reveals its name, period and moon count, while Saturn shows its ring system. Models like this underpin ephemeris calculations astronomers use to point telescopes and plan spacecraft trajectories.
What does this simulation show?
It is a 3D heliocentric model of our Solar System with all eight planets orbiting a central Sun. Each planet sits at its scaled orbital radius and circles the Sun at a rate set by its real orbital period, so you can watch the inner planets race while Jupiter, Saturn, Uranus and Neptune crawl.
How are the orbits calculated?
Each planet's angular position is found from theta equals two pi times the elapsed simulated time divided by that planet's period in years. The simulation then places the planet at x equals radius times cosine theta and z equals radius times sine theta, advancing every frame so the relative speeds match reality.
What do the three sliders do?
Speed multiplies how quickly simulated time advances, making the orbits faster or slower. Planet size visually scales every globe between 0.3 and 3 times without changing the physics. Orbital trails sets the length of the fading line drawn behind each planet, from off up to 500 points.
This follows Kepler's Third Law, where the orbital period squared is proportional to the semi-major axis cubed. A planet closer to the Sun has both a shorter path and a faster orbital speed, so Mercury completes a lap in under three months of simulated time while Neptune needs 165 years.
The orbital radii and periods are at true relative scale, so the timing and spacing of the planets are realistic. The planet diameters, however, are exaggerated for visibility. At true scale the planets would be invisible specks, since most of the Solar System is empty space.
It states that the square of a planet's orbital period equals the cube of its semi-major axis when period is measured in years and distance in astronomical units, written as T squared equals a cubed. It links how far a planet orbits to how long that orbit takes, and it governs the relative speeds you see here.
Johannes Kepler showed planetary orbits are ellipses with the Sun at one focus, not perfect circles. This simulation draws circular paths for clarity, but the timing rule it uses comes directly from Kepler's laws, which describe how real elliptical orbits sweep equal areas in equal times.
Saturn is rendered with a flat ring of ice and rock, tilted to match its real orientation. The small grey dots orbiting several planets represent a simplified set of moons, such as Earth's single Moon, Mars's two and Jupiter's largest few, circling their host as it travels.
The Year readout tracks elapsed simulated time in Earth years, driven by the Speed slider. It is the value plugged into the orbit equation, so a higher number means the planets have completed more revolutions. Pressing Reset returns the year to zero and rebuilds the scene.
Scaled orbital models are the basis of ephemerides, the tables of predicted planetary positions used to aim telescopes, schedule observations and plan interplanetary missions. Understanding the architecture of our Solar System also helps scientists interpret the orbits of planets discovered around other stars.
Yes. Drag to rotate the view, scroll to zoom in or out, and hover the cursor over any planet to bring up a tooltip showing its name, description, orbital period in years and number of moons. The side panel also lists every planet with its colour swatch.