• Question: Why will the sun run out in approximately 3.5 billion years?

    Asked by alex1996 to Amy, Drew, Julia, Kimberley, Sara on 13 Jun 2011. This question was also asked by mizzerie150, akyofori, luke9897, maximillian.
    • Photo: Drew Rae

      Drew Rae answered on 13 Jun 2011:

      Alex,
      The simple answer is that the sun runs on hydrogen as a fuel. It converts the hydrogen to helium by a process known as fusion, and that’s where the energy comes from. Once most of the hydrogen is converted to helium, there won’t be enough to keep the reaction going.

    • Photo: Amy MacQueen

      Amy MacQueen answered on 13 Jun 2011:

      Yeah, its based on calculations about the way the Sun works – nothing lasts forever in this universe…

    • Photo: Kimberley Bryon

      Kimberley Bryon answered on 13 Jun 2011:

      Just like us stars such as the sun undergo a lifecycle. As Drew said this is based on hydrogen fuel. Eventually, the sun will turn in to a red giant and then die.

    • Photo: Julia Griffen

      Julia Griffen answered on 13 Jun 2011:

      Nice question Alex…

      The masters of the internet suggest 5 million years…
      The Sun is basically a massive nuclear power station. Hydrogen nuclei are compressed into helium nuclei with the loss of a small amount of mass that is converted into an equivalent amount of energy. When all of the Sun’s hydrogen has been fused into helium, the Sun will no longer be able to power itself as it does now. This will occur in about 5 billion years. The Sun will then start to collapse, and the increasing pressure will allow the Sun to start fusing helium into carbon and oxygen, and it will expand into a red giant. The Sun is not massive enough to fuse elements heavier than oxygen, so it will just shed its outer layers while the core cools over tens of billions of years….

      A while left yet then…whether the human population will survive that long is another question altogether!

    • Photo: Sara Imari Walker

      Sara Imari Walker answered on 13 Jun 2011:

      Hey alex1996. I think Julia here has provided a great answer. Our sun will run out of Hydrogen to burn in about 5 billion years and become a red giant. That’s bad for us because at that point the Sun will expand to encompass the Earth’s orbit!! It will be a very big star!

      Perhaps more relevant to us now – in about 1 billion years the Sun will be much hotter than it is today – possibly making it too hot to live on the Earth. Although 1 billion years is A LOT closer than 5, its still long enough away that we don’t need to worry about it! Thankfully! I don’t know about you but I like living here =)

Comments