Well - personally I don't think our planet is at risk. In long term yes it is. Some hundreds of millions of years from now, it is. But in near future, simply isn't any credible natural disaster that would make us extinct. Asteroid impact certainly wouldn't, for as long as we retain the technology we now have.
Asteroid impact - best thing is to learn to predict it and divert it, with SpaceGuard. And a 0.0001% chance of a Dinosaur type asteroid impact before end of the century, with this risk going down all the time as we plot a higher and higher percentage of potential impactors.
But even that is not extinction causing - the dinosaurs did not have our technology and even if they couldn't deflect it, with our technology they could have survived and reseeded the planet after the impact..
Gamma ray burst - not too likely to happen in near future - hard to assess but probably far lower chance than that 0.0001% - and again - half the planet would be unaffected (shielded by it). Does damage the ozone layer. But the survivors could shield themselves from the suns rays until the ozone layer heals - possibly do things to actively heal the layer - and protect vital crops and animals or whatever - and eventually reseed the planet and survive just as for the asteroid impact.
See
Robert Walker's answer to What is the probability of a significant asteroid impact event by 2100?
So - I beg to differ with the distinguished scientists who have said we have good reasons to go to Mars. They have said many good things - but just because you admire someone doesn't mean you have to just blindly agree with everything they say. And Sagan of course was writing some decades ago and science has advanced a fair while since then.
I simply don't know if he'd say the same thing today.
Mars also, nowadays - not so much then just after Viking - seems to be potentially of great value for study of life, so good reasons to keep it pristine, good scientific reasons.
And - are other places we can colonize. If we really want to do it. We can create a Stanford Torus type settlement, with Earth like conditions - for far far less cost than we could hope to achieve on Mars by terraforming it. And far sooner also, in a few decades rather than 1000 years.
So - I'm not sure myself if we should colonize. Feel sure we don't have to colonize to avoid extinction. Feel that if done too rapidly - it might lead to disaster if we just export all our problems on Earth to millions of people living in space - with the same economic issues, violence, terrorism, warfare, dictators, crazy people with weapons etc - all written large in space with everyone having access to powerful weapons and in habitats so fragile - and spacesuits where a simple mistake will kill you - and habitats that would be completely destroyed by an out of control (or terrorist controlled) spaceship traveling at kms / second.
I'm just not sure we are ready yet. But if we are - feel Stanford Torus is the way to go, not Mars.
And - but what we can do is to explore - so go into space - possibly as humans - possibly just as robots - to find out as much as we can about our solar system and about Earth. That, I feel - that can't be a problem.
So let's encourage exploration of space. With no end date.
Which may include settlement as long as it doesn't interfere with the science and discovery. But let's postpone colonizing for at least a few decades. Is no hurry at all to get started.
If we do go extinct in the next few decades, would be through our own hands. And going into space is not a way to escape from ourselves if we ourselves are the problem - that will only make things worse, I feel.
See also Let's Plan For Exploration and Discovery of Space with no End Date - NOT Escape from Earth - Opinion Piece
Asteroid impact - best thing is to learn to predict it and divert it, with SpaceGuard. And a 0.0001% chance of a Dinosaur type asteroid impact before end of the century, with this risk going down all the time as we plot a higher and higher percentage of potential impactors.
But even that is not extinction causing - the dinosaurs did not have our technology and even if they couldn't deflect it, with our technology they could have survived and reseeded the planet after the impact..
Gamma ray burst - not too likely to happen in near future - hard to assess but probably far lower chance than that 0.0001% - and again - half the planet would be unaffected (shielded by it). Does damage the ozone layer. But the survivors could shield themselves from the suns rays until the ozone layer heals - possibly do things to actively heal the layer - and protect vital crops and animals or whatever - and eventually reseed the planet and survive just as for the asteroid impact.
See
Robert Walker's answer to What is the probability of a significant asteroid impact event by 2100?
So - I beg to differ with the distinguished scientists who have said we have good reasons to go to Mars. They have said many good things - but just because you admire someone doesn't mean you have to just blindly agree with everything they say. And Sagan of course was writing some decades ago and science has advanced a fair while since then.
I simply don't know if he'd say the same thing today.
Mars also, nowadays - not so much then just after Viking - seems to be potentially of great value for study of life, so good reasons to keep it pristine, good scientific reasons.
And - are other places we can colonize. If we really want to do it. We can create a Stanford Torus type settlement, with Earth like conditions - for far far less cost than we could hope to achieve on Mars by terraforming it. And far sooner also, in a few decades rather than 1000 years.
So - I'm not sure myself if we should colonize. Feel sure we don't have to colonize to avoid extinction. Feel that if done too rapidly - it might lead to disaster if we just export all our problems on Earth to millions of people living in space - with the same economic issues, violence, terrorism, warfare, dictators, crazy people with weapons etc - all written large in space with everyone having access to powerful weapons and in habitats so fragile - and spacesuits where a simple mistake will kill you - and habitats that would be completely destroyed by an out of control (or terrorist controlled) spaceship traveling at kms / second.
I'm just not sure we are ready yet. But if we are - feel Stanford Torus is the way to go, not Mars.
And - but what we can do is to explore - so go into space - possibly as humans - possibly just as robots - to find out as much as we can about our solar system and about Earth. That, I feel - that can't be a problem.
So let's encourage exploration of space. With no end date.
Which may include settlement as long as it doesn't interfere with the science and discovery. But let's postpone colonizing for at least a few decades. Is no hurry at all to get started.
If we do go extinct in the next few decades, would be through our own hands. And going into space is not a way to escape from ourselves if we ourselves are the problem - that will only make things worse, I feel.
See also Let's Plan For Exploration and Discovery of Space with no End Date - NOT Escape from Earth - Opinion Piece
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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