Ask Me A Question – Q&A Forum

When Will The Sun Run Out Of Energy?

This question originally came from the Ask Me A Question blog, where it was submitted by Anony Mouse. We are opening it up here as a forum discussion as well.

Anony Mouse wrote: We know that eventually everything has an end, but will it all truly disappear? One thing we know is that the Sun will eventually die when it runs out of fuel. So when will the Sun run out of energy and reach the end of its life?

This is one of those space questions that sounds gloomy but is actually fascinating. The Sun will not last forever, but its remaining lifetime is measured on a scale far beyond ordinary human history.

The question also opens up wider discussion about stars, planets, the future of Earth, and what "the end" really means in astronomy.

A few points to discuss:

• How long do stars like the Sun usually last?
• What happens when the Sun reaches the later stages of its life?
• What would happen to Earth in the far future?
• Does thinking about cosmic timescales change how you see human history?
• Which facts about the Sun's future surprised you most?

The original blog answer is here:

When Will The Sun Run Out Of Energy?

Add your thoughts below.