How will life end on Earth?
What will cause the end of life on planet Earth? Will it be the when the sun dies or something else?
Graihagh - Will hungry humans be the cause of the apocalypse or will it be something like the catastrophic comet that cause the dinosaurs to go extinct? We put it to you on Facebook and Paul came back with this...
Paul - Humans may survive, breeding, warring, poisoning, destroying and plundering forever but I fear, nothing habitable will be left behind, for humans are cancer to all life.
Graihagh - Whereas Jeremy thought life was just to hardy to ever go extinct.
Jeremy - Life is persistent stuff. NASA tried to create a sterile room to build Mars rovers to prevent interplanetary contamination. What did they find? Bacteria that evolved to eat the paint in the sterile room.
Graihagh - So, will life always find a way to endure, no matter what happens to Earth? To find out, we spoke to Astronomer Royal, Martin Reese from Cambridge University.
Martin - We know that the sun will die in about 6 billion years. When that happens, it'll flare up, become a red giant and engulf the inner planets and end any life remaining on Earth. Long before that, in fact, life have become uncomfortable on Earth because the sun is getting brighter all the time. So after about 1 billion years from today, the ocean would start to boil.
Graihagh - The Atlantic boiling, our sun exploding... 6 billion years from now, do we have any hope?
Martin - I would expect it in a few hundred years, there'll be communities living away from the Earth on asteroids or on Mars and they will in fact, use genetic technology and cyborg technology to modify themselves. So, they'll be post humans already. But if we imagine that the Earth has ahead of it, more time that it's taken to go all the way from simple organisms to humans, then we can imagine that by the time the sun dies, there'll be life descended from human life, all through the galaxy perhaps and taking many different forms.
Graihagh - So, human life may end on Earth but not elsewhere in the universe. Thanks, Martin. Next week, we'll be twirling our moustaches over this beaded beauty of a question sent in by listener Mark...
Mark - I've been taking part in November which is a fundraising for cancer research where men raise money by growing moustache over the course of the month of November. Hence, that 'M' in November. It's been 10 years since I've grown any hair on my chain and this year, it's growing white. The hair on my head isn't white, it's not grey. My question is, why is my facial hair growing white and I don't really want people to think I'm dying it.