Follow-up observations are required to determine further properties. The rotation period, rotation axis, shape constraints and phase curve can be determined from extended optical photometry. Thermal infrared spectrophotometry longer than 5 μm, combined with an appropriate thermal model and optical photometry, can be used to determine the asteroid’s diameter and albedo. The albedo of an asteroid can constrain the taxonomic class and is vital for investigating the mineralogy. The size distribution and thermophysical properties of NEAs can help us to understand their evolution and the observed size distribution can be compared with the results of collisional evolution models. Size, shape and thermal properties can possibly distinguish the presence of extinct comets and can help constrain the Yarkovsky effect.