A Terminal Total Difficulty (TTD) of 50000000000000000 has been selected for the Ropsten Merge. Stakers and node operators must manually override the TTD in both their execution and consensus layer clients before June 7, 2022. Proof-of-Work testnets can have volatile hash rates and the exact timing of The Merge on…

Source and More information: Ropsten TTD Announcement

Author: Ethereum.org