How many years until the Sun stops burning?

Ah, an intriguing question indeed! The Sun is a main-sequence star, and as such, it is currently fusing hydrogen atoms into helium in its core, generating immense amounts of energy and light in the process. But the question is, how long can this fusion reaction last? Well, scientists estimate that the Sun has enough hydrogen fuel to sustain its fusion reaction for approximately another 5 billion years. After that, the CORE of the Sun will begin to contract, causing the outer layers of the star to expand and eventually become a red giant. During this phase, the Sun will engulf the inner planets, including Mercury and Venus, and potentially even Earth. But to directly answer your question, it's estimated that the Sun will continue to burn for another 5 billion years before it runs out of hydrogen fuel and begins to transition into a red giant. Of course, this is just an estimate based on current scientific understanding, and we may discover new information in the future that changes this timeline.