These files serve as publicly available data to follow the publication titled 'Lunar samples record an impact 4.2 billion years ago that may have formed the Serenitatis Basin' accepted in Communications Earth & Environment (Nature Springer). Supplementary Data 1. A zip folder containing iSALE code modelling input parameters for 1) Serenitatis Basin formation at 4.5 and 4.0 Gyr; 2) Dawes crater and ejecta formation, and 3) Dawes ejecta landing. Details on the modelling are provided in Supplementary Methods 1.2 and Supplementary Discussion 2.3. of the published article. Supplementary Data 2. An Excel spreadsheet containing U-Pb and Pb-Pb dating results presented in Supplementary Table 2. Supplementary Movie 1. Mg distribution in the Atom Probe Tomography microtip M3 of shocked lunar apatite. Polygonal grains of lunar apatite can be recognized by the magnesium decoration of grain boundaries. Supplementary Movie 2. Mg-decorated grain boundaries in the Atom Probe Tomography microtip M3 of shocked lunar apatite. Mg atoms (blue dots) and a 0.13 at. % magnesium isosurface (purple) in a 5 nm slice of the apatite data as it is moved through the needle from one side to the other, show the shape of the grain boundaries.