The MODIS Terra MOD21A2 Version 6.1 product provides an 8-day composite of Land Surface Temperature (LST) and emissivity at 1 km spatial resolution. The dataset is based on the ASTER Temperature/Emissivity Separation (TES) algorithm, which retrieves LST and spectral emissivity simultaneously from MODIS thermal infrared bands 29, 31, and 32 using a physics-based approach combined with a Water Vapor Scaling (WVS) atmospheric correction method. The product is generated by averaging all cloud-free observations from the MOD21A1D (daytime) and MOD21A1N (nighttime) daily acquisitions within the 8-day compositing period. Both daytime and nighttime observations are included in a single file as separate science data layers, including LST, quality control (QC), view zenith angle, and observation time, while emissivity values for bands 29, 31, and 32 represent the average of both daytime and nighttime measurements.