• Question: When will the earth end? if so why? (the sun, etc.)

    Asked by conchod123 to Antonia, Douglas, Hugh, Matt, Tom on 25 Jun 2010 in Categories: . This question was also asked by bigconor123, chelseastadames, hannahcottrell, maddieplant.
    • Photo: Matthew Hurley

      Matthew Hurley answered on 14 Jun 2010:

      I don’t think anyone can tell you that – if they do they’re probably just guessing – they’ll never be proved wrong unless they say ‘tomorrow’!.

    • Photo: Hugh Roderick

      Hugh Roderick answered on 15 Jun 2010:

      The earth will end in about 5 billion years when the sun runs out of fuel and starts to expand out to the orbit of mars. What will have become of the human race by this point is anyone’s guess!

    • Photo: Tom Hardy

      Tom Hardy answered on 15 Jun 2010:

      The date is impossible to answer accurately; there is no way of knowing and potentially a lot of ways the Earth could end.

      It also depends on whether you mean the Earth as a planet or life on Earth. I think the planet will exist as long as the universe does. There isn’t much that could destroy the entire Planet.

      Life on Earth could be wiped out much more easily. My personal view is that a virus of some kind will mutate into a deadly strain with no cure which could quickly spread throughout the world and kill everyone. But some people will be naturally immune and we have really sophisticated medical processes now that could find a vaccine or a cure so this probably won’t kill everyone.

      A massive meteor could hit the Earth, although this wouldn’t necessarily wipe all life out immediately, the impact would create a missive ash cloud – many times bigger than the recent volcano ash cloud. A big ash cloud like that could cover the entire globe and block out sunlight, without sunlight plants cannot photosynthesise and food chains would begin to break and eventually everyone on Earth could perish. Many people believe it is an impact like this that killed the dinosaurs.

    • Photo: Douglas Blane

      Douglas Blane answered on 25 Jun 2010:

      It’s most likely to end when the sun has used up most of its nuclear fuel – which is hydrogen.

      The sun and stars produce heat and light most of their lives through nuclear fusion, which turns hydrogen into helium.

      What happens when most of the hydrogen is gone is that the sun’s gravity makes it collapse. That increases the pressure and temperature deep inside.

      It then gets hot enough down there for fusion to start with all the helium that’s been produced. That happens quite suddenly and very fiercely, which blows the rest of the sun out.

      It’s now much bigger than before. It’s also much cooler, because it’s spread over a bigger volume and it’s producing less energy.

      The sun has become a Red Giant.

      And the earth has got swallowed up inside it.

      There’s a nice vid on this and what happens to Earth here: http://www.youtube.com/watch?v=8TAEmd4PZOk

      We’re talking about 5 or 6 billion years in the future, by the way, so nothing for us to worry about.