Footprint of the ZTF alert stream from November 2019 to December 2022 associated with different subsets: the 15 381 246 alerts associated with confirmed Solar System objects (left; see Sect. 3.1), the 389 530 alerts associated with Solar System object candidates (middle; see Sect. 3.2), and the 2205 alerts associated with reconstructed orbits (right; see Sect. 5). The sky maps are in equatorial coordinates, and ZTF does not observe for declination lower than ≈−30 degrees. For each footprint, we use the HEALPix pixelisation algorithm with a resolution parameter equals to Nside=32 (Gorski et al. 2005) and the color scheme displays the number of alert per arcminute square. The color scale for the rightmost footprint has been inverted compared to the two others for a better readability. For reference, the ecliptic plane is shown with black triangles.