This top-down view solves the same Kepler's equation M = E − e·sin(E) as the 3D version, but proves the equal-area law differently: two fixed, shaded wedges are drawn — one straddling perihelion, one straddling aphelion — each spanning the same fixed slice of time. Because the areas stay equal no matter how you change the orbit's shape, they are a direct visual (and numeric) proof of Kepler's second law, side by side rather than as a single moving sweep.
Speed still follows vis-viva, v² = GM(2/r − 1/a): fastest at perihelion, slowest at aphelion. The sublimation model here uses a logistic activation threshold (activity turns on sharply past a characteristic distance, as real cometary ices do) rather than the inverse-square falloff used in the 3D engine — a genuinely different, still-physical approximation of the same sublimation phenomenon. The ion tail always points radially away from the Sun; the dust tail curves, lagging the orbital path under radiation pressure.
M = E - e sin(E) (Kepler's equation)
r = a(1 - e cos E) (radius)
v² = GM(2/r - 1/a) (vis-viva speed)
activity = sub / (1 + exp((r - r0)·k)) (logistic sublimation onset)
Click near the orbit path to jump the comet there; drag empty space to pan, scroll/pinch to zoom.