Ropsten will be Ethereum’s first public test network to transition from proof-of-work (PoW) to a proof-of-stake (PoS) consensus mechanism as part of the blockchain’s “Merge” event, expected August this year.

Ethereum core developer Tim Beiko shared the news on Twitter last night: “Ethereum's longest-lived PoW testnet is moving to Proof of Stake! A new beacon chain has been launched today, and The Merge is expected around June 8th on the network.”

Beiko called the news a “first dress rehearsal” for miners.

📣 Ropsten Merge Announcement 📣 Ethereum's longest lived PoW testnet is moving to Proof of Stake! A new beacon chain has been launched today, and The Merge is expected around June 8th on the network. Node Operators: this is the first dress rehearsal💃https://t.co/0fDHObLOmn — Tim Beiko | timbeiko.eth 🐼 (@TimBeiko) May 30, 2022

Beiko then fired off a nine-tweet thread covering the technical details of the Merge for miners. He informed developers that “basically nothing should change” post-Merge.

Ropsten’s newly-launched beacon chain will undergo a “Bellatrix” upgrade to be Merge-compatible around June 2. A few days after this, a value known as the Terminal Total Difficulty (TTD) will be chosen by miners to trigger the transition. Miners will then need to configure their nodes with this value.

According to a blog post by Ethereum: “After the Ropsten transition, two more testnets (Goerli and Sepolia) will be transitioned to proof-of-stake before focus shifts to mainnet.”

The Ethereum Foundation also upped its bug bounty payouts recently to help facilitate a problem-free transition.

Ethereum, Testnets, and the Merge

Launched in 2016, Ropsten is Ethereum’s longest-running PoW test network (testnet). Testnets are identical in every key aspect to the “mainnet,” and are used by developers to test smart contracts and decentralized applications (dApps).

Ropsten uses a valueless form of Ethereum to execute transactions and test the coding environment. Changes made to the testnet do not affect Ethereum’s mainnet. This consequence-free environment gives developers key insights into any potential problems that might arise from their coding.

Formerly known as 2.0, Ethereum’s long-anticipated mega upgrade will transition the network from a consumptive PoW consensus algorithm à la Bitcoin – where transactions are validated by miners with a lot of computing power – to PoS, in which miners who put up the most collateral validate the most transactions.

Ethereum claims this will cut the blockchain’s energy consumption by up to 99.5%.

"The merge" refers to the point when Ethereum’s mainnet will converge with the PoS-based Beacon Chain. After that, Ethereum 2.0 (which was recently rebranded to the “Consensus Layer”) will be up and running.