Orbital geometry of the 25 HST observations. The heliocentric orbits of 288P (green) and Earth (violet) are shown in projection onto the ecliptic plane, viewed from North. Zero ecliptic longitude is along the positive x-axis. The Sun is located in the origin of the coordinate system. Numbers show the positions of 288P and Earth during the concerned visit, and grey lines indicate the corresponding line of sight. The blue point indicates one focal point of the binary orbit, while the red point indicates the relative position of the other component. The binary orbit is not to scale, and orbit drawings for visits 2, 4, 7, and B have been omitted for clarity.