Well there's never been such an asteroid since life first evolved on Earth over 4 billion years ago. After all we are still here, there have been several mass extinctions but none of them that made all life extinct.
But if it was a blast the size of the one that brought an end to the dinosaurs, then you'd be hit by a hurricane force wind if you were within about 2000 km of the impact site. Outside of that, especially if you were on the other side of the world, I think you would survive.
And then look for a safe place to land and search for a submarine. Or a deep cave
Or indeed if you can get hold of an aqualung and dive into the sea. You just need to survive an hour under water to escape the worst of the firestorm.
That is, if it is true that the larger asteroids start a global firestorm. The asteroid started the fire (or did it?) Integrative Paleontologists
If some of the worst things that could happen actually happen, you probably wouldn't want to still be flying after the impact - to try to out fly the fire storm - with small spherules created during the impact falling on the Earth world wide and heating up the upper atmosphere to hotter than oven temperatures.
Anyway - there's no way it would happen without any warning. You'd have known about it for many months and most likely for several years in advance. You are talking here about something nearly as large as Mars's outer moon Deimos.
So if you are in a plane, it's because you've already decided it is safe to fly during the impact itself. Maybe you are a news reporter, or maybe you are flying to some safe place already.
Remember the dinosaurs didn't have planes or cars or boats or submarines or fireproof shelters. And many mammals also and crocodiles and birds, and turtles - they all survived. So some humans with technology will surely survive.
And with months or most likely years of warning, surely there'd be a world wide program to equip everyone with fireproof shelters, aqualungs, supplies of oxygen, swimming pools to shelter under from the firestorm, or whatever is needed.
But for something as big as this, it's a better bet to deflect it. And this we probably will be able to do, as we'd be likely to know about it for centuries in advance.
They are rare events, only one chance in a million of being hit by something this big in the next century.
So - much more likely to discover smaller asteroids first - they are far more common.
And can develop methods and technology for those first. And then with experience of those, will be able to deflect the larger ones too once we know about them.
You might be interested in signing the 100 times foundation petition
Asteroid Day - 100 times petition
We already spend a fair bit on asteroid defence.
But this is a petition to increase spending on asteroid defence 100 times. On the basis that unusually amongst the many natural hazards we face - this is a hazard we can do something about with our technology.
We can't stop a volcano erupting or an earthquake - at least not yet - but you can stop an asteroid impacting Earth. We know many ways to do that, given enough time. And the way that you get lots of time is by plotting them all so you know many decades, or even centuries in advance.
The day they chose as "Asteroid Day" for awareness of the issues is June 30th, 2015. So quite soon.
- already signed by many famous astronomers and astronauts.
You can also donate to the B612 foundation who aim to put a dedicated asteroid watching telescope into orbit.
Sentinel Mission
But if it was a blast the size of the one that brought an end to the dinosaurs, then you'd be hit by a hurricane force wind if you were within about 2000 km of the impact site. Outside of that, especially if you were on the other side of the world, I think you would survive.
And then look for a safe place to land and search for a submarine. Or a deep cave
Or indeed if you can get hold of an aqualung and dive into the sea. You just need to survive an hour under water to escape the worst of the firestorm.
That is, if it is true that the larger asteroids start a global firestorm. The asteroid started the fire (or did it?) Integrative Paleontologists
If some of the worst things that could happen actually happen, you probably wouldn't want to still be flying after the impact - to try to out fly the fire storm - with small spherules created during the impact falling on the Earth world wide and heating up the upper atmosphere to hotter than oven temperatures.
YOU WOULD KNOW ABOUT IT ANYWAY
Anyway - there's no way it would happen without any warning. You'd have known about it for many months and most likely for several years in advance. You are talking here about something nearly as large as Mars's outer moon Deimos.
So if you are in a plane, it's because you've already decided it is safe to fly during the impact itself. Maybe you are a news reporter, or maybe you are flying to some safe place already.
UNLIKE DINOSAURS, SOME HUMANS WOULD SURVIVE
Remember the dinosaurs didn't have planes or cars or boats or submarines or fireproof shelters. And many mammals also and crocodiles and birds, and turtles - they all survived. So some humans with technology will surely survive.
And with months or most likely years of warning, surely there'd be a world wide program to equip everyone with fireproof shelters, aqualungs, supplies of oxygen, swimming pools to shelter under from the firestorm, or whatever is needed.
DEFLECTING IT
But for something as big as this, it's a better bet to deflect it. And this we probably will be able to do, as we'd be likely to know about it for centuries in advance.
RARE EVENTS
They are rare events, only one chance in a million of being hit by something this big in the next century.
So - much more likely to discover smaller asteroids first - they are far more common.
And can develop methods and technology for those first. And then with experience of those, will be able to deflect the larger ones too once we know about them.
PETITION TO SPEND 100 TIMES AS MUCH AS WE DO ALREADY ON SEARCH FOR NEAR EARTH ASTEROIDS
You might be interested in signing the 100 times foundation petition
Asteroid Day - 100 times petition
We already spend a fair bit on asteroid defence.
But this is a petition to increase spending on asteroid defence 100 times. On the basis that unusually amongst the many natural hazards we face - this is a hazard we can do something about with our technology.
We can't stop a volcano erupting or an earthquake - at least not yet - but you can stop an asteroid impacting Earth. We know many ways to do that, given enough time. And the way that you get lots of time is by plotting them all so you know many decades, or even centuries in advance.
The day they chose as "Asteroid Day" for awareness of the issues is June 30th, 2015. So quite soon.
- already signed by many famous astronomers and astronauts.
OR SUPPORT SPACE TELESCOPE TO LOOK FOR THEM
You can also donate to the B612 foundation who aim to put a dedicated asteroid watching telescope into orbit.
Sentinel Mission
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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