Notes. The equivalent space weathering years by our simulation experiments can be roughly estimated by assuming that all kinetic energy from micrometeoroid bombardments on asteroids would convert into heat and that the micrometeoroid flux does not change over time (Zhang et al. 2022). The equivalent years of space weathering was calculated using the formula C = B / A, where B denotes the energy density (i.e., total deposited energy by laser per square meter in our experiments) and A denotes the deposited energy per square meter per year on airless bodies. The formula to calculate B is B = TE/π r², where TE represents the laser total energy in our experiment (unit in J) and r represents the radius of each laser spot (i.e., 2.5 × 10⁻⁴ m) in our experiments. The formula to calculate A is A = 1/2 mv² FT, where m represents the mass of each dust particle (i.e., 10⁻¹⁵ kg), v represents impact velocity (i.e., 15 km s⁻¹ for the Moon and 8.62–12 km s⁻¹ for Phobos), F represent impact flux (i.e., 10⁻⁴m⁻² s⁻¹), and T represents impact time (i.e., 365 × 24 × 3600 s).