Frame
Heliocentric ecliptic J2000. Units = AU throughout (1 AU = 149 597 870.7 km). +X toward vernal equinox, +Z = ecliptic north pole, +Y completes the right-handed system. µ☉ = 4π² AU³ / yr² by definition; Kepler's third law gives T(yr) = a(AU)^1.5 for two-body solar orbits.
Planets
Mercury, Venus, Earth, Mars are propagated as Keplerian ellipses from VSOP87 / DE441 mean elements at J2000. For visual fidelity the planet markers are dramatically oversized (Earth at true radius is 4.3 × 10⁻⁵ AU — invisible at any scale where Mars orbit is also visible). Markers are not to scale; planet orbits are.
Heliocentric orbiters
Parker, Solar Orbiter, STEREO-A and BepiColombo are each in a single Kepler ellipse around the Sun. Parker's orbit is the post-VGA-7 configuration (perihelion 0.046 AU = 9.86 R☉, aphelion 0.73 AU, period 88 d). Solar Orbiter is its 2026-era post-VGA orbit (perihelion 0.293 AU, inclination 24°). STEREO-A is its Earth-leading heliocentric orbit (a = 0.961 AU, period 344 d). BepiColombo is a representative cruise ellipse — its actual transfer trajectory is many-flyby and would require Horizons interpolation for accurate phase. Mercury orbit insertion is November 2026.
Lagrange points and halo orbits
Sun-Earth L1 sits 0.01001 AU sunward of Earth (1.496 × 10⁶ km); L2 sits 0.01007 AU anti-sunward (1.507 × 10⁶ km). Both are computed each frame from Earth's instantaneous heliocentric position. Lagrange platforms are placed on Lissajous halo orbits in the Sun-Earth rotating frame, with amplitudes (Ax, Ay, Az) and period (~180 d) tabulated per platform from published mission halo parameters. The rotating-frame halo position is then rotated by Earth's heliocentric longitude back into the inertial frame. The resulting motion in the inertial frame is the halo orbit you see at the Earth & Lagrange preset.
Outbound spacecraft
Voyager 1, Voyager 2, Pioneer 10, Pioneer 11 and New Horizons are well outside the inner solar system and on essentially straight-line escape trajectories at this scale. Each is rendered as a direction vector from the Sun out to the current published heliocentric distance, in J2000 ecliptic coordinates derived from the published spacecraft pointing (RA / Dec / heliocentric distance from JPL Horizons). They appear as arrow tips at the edge of the inner-system view; toggle the Outer preset to see them at true distance.