More recently, scientists use CMB measurements (such as Planck 's data) to determine the Hubble constant. The challenge of using this method is that its result varies depending on the cosmology models used. Due to the different values of Hubble constant estimated using different techniques, the determination of Hubble constant is an active research field (Hubble tension). The high accuracy measurement using James Webb Space Telescope in 2023 has confirmed the earlier observation of the Hubble Space Telescope, which gave a Hubble constant about H 0 = 74 (km/s)/Mpc.