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Yesterday I asked: What do you think is the bigger threat to our modern human society?
Poll result: 31% for #asteroids, 69% for #solarstorms.
I‘ll argue that solar storms have a far greater potential for disruption to our society in our lifetime.
A threat-comparison-thread
Poll result: 31% for #asteroids, 69% for #solarstorms.
I‘ll argue that solar storms have a far greater potential for disruption to our society in our lifetime.
A threat-comparison-thread
1/15:
Intuitively, a small and solid thing hitting a big solid thing should be much worse than an interaction of magnetic fields, right? If we talk about extinction of humanity, an asteroid could indeed do it, but such a large asteroid impact is very very very ... unlikely.
Intuitively, a small and solid thing hitting a big solid thing should be much worse than an interaction of magnetic fields, right? If we talk about extinction of humanity, an asteroid could indeed do it, but such a large asteroid impact is very very very ... unlikely.
2/15
1. Asteroids
For a space rock to reach the surface intact needs to be roughly ~ 100 m in diameter - this happens every 5000 years on average. The damage to humans depends a lot on the impact location, but mankind inhabits only a few percent of the total Earth surface area.
1. Asteroids
For a space rock to reach the surface intact needs to be roughly ~ 100 m in diameter - this happens every 5000 years on average. The damage to humans depends a lot on the impact location, but mankind inhabits only a few percent of the total Earth surface area.
3/15
For an impactor to cause global effects, regardless of where it lands, rocks are needed with 1 km diameter, and now we are easily in the 500 000 to 1 million years frequency zone, and with a 10 km event every 100 million years, we would be in dinosaur-extinction-territory.
For an impactor to cause global effects, regardless of where it lands, rocks are needed with 1 km diameter, and now we are easily in the 500 000 to 1 million years frequency zone, and with a 10 km event every 100 million years, we would be in dinosaur-extinction-territory.
4/15
In a human lifetime of 100 years, an impact of a rock with just 25 m diameter is expected. It will burst in the atmosphere, like in Chelyabinsk in 2013, and will produce only some local damage, depending of course on the location of this "airburst" with respect to humans.
In a human lifetime of 100 years, an impact of a rock with just 25 m diameter is expected. It will burst in the atmosphere, like in Chelyabinsk in 2013, and will produce only some local damage, depending of course on the location of this "airburst" with respect to humans.
5/15
2. Solarstorms
... are enormous clouds of plasma with embedded magnetic fields, and they impact Earth's magnetic field on average twice per month. Currently, the Sun is magnetically almost completely quiet, and this year only 8 weak solar storms have hit Earth.
2. Solarstorms
... are enormous clouds of plasma with embedded magnetic fields, and they impact Earth's magnetic field on average twice per month. Currently, the Sun is magnetically almost completely quiet, and this year only 8 weak solar storms have hit Earth.
6/15
However, averaged over a full solar cycle, the Sun produces on average 2 solar storms per DAY, but they can be launched into almost all 360° directions around the solar sphere. In the vastness of space, Earth is really small, and asteroids are absolutely tiny.
However, averaged over a full solar cycle, the Sun produces on average 2 solar storms per DAY, but they can be launched into almost all 360° directions around the solar sphere. In the vastness of space, Earth is really small, and asteroids are absolutely tiny.
7/15
But solar storms are very very big, so some part of them often sweeps over the Earth. Many solar storms are of course slow and weak, they swim along with the solar wind, and so many lead to no minor effects or spark aurorae in countries like Canada, Iceland or Norway.
But solar storms are very very big, so some part of them often sweeps over the Earth. Many solar storms are of course slow and weak, they swim along with the solar wind, and so many lead to no minor effects or spark aurorae in countries like Canada, Iceland or Norway.
8/15
But there are also the really bad ones, and they happen far more often than people are in generally aware of. We know from the power law distribution of their parameters that the big one happens once in 100 years, or there is a chance of ~10% in each decade or solar cycle.
But there are also the really bad ones, and they happen far more often than people are in generally aware of. We know from the power law distribution of their parameters that the big one happens once in 100 years, or there is a chance of ~10% in each decade or solar cycle.
9/15
We aren't sure either if that is the end of the line - maybe a 1 in a 1000 years event could be worse by another order of magnitude, but there are definitely limits to what the Sun can produce in terms of ejecting plasma with high speeds and magnetic field magnitude.
We aren't sure either if that is the end of the line - maybe a 1 in a 1000 years event could be worse by another order of magnitude, but there are definitely limits to what the Sun can produce in terms of ejecting plasma with high speeds and magnetic field magnitude.
10/15
Given that since 1859 and 1921 no really big solar storm impact at Earth has happened in the space or internet ages, no one knows exactly what will happen during the big one, but check the 1989 Quebec power outage for a sneak peek. And in 2012 we even dodged a big one.
Given that since 1859 and 1921 no really big solar storm impact at Earth has happened in the space or internet ages, no one knows exactly what will happen during the big one, but check the 1989 Quebec power outage for a sneak peek. And in 2012 we even dodged a big one.
11/15
Researchers have tried to figure out the possible economic effects after a big solar storm impact, and the numbers go into billions of losses, mainly caused by power grid failures, and thats often calculated for just one country.
Researchers have tried to figure out the possible economic effects after a big solar storm impact, and the numbers go into billions of losses, mainly caused by power grid failures, and thats often calculated for just one country.
12/15
While an asteroid impact has been visualized in movies like Deep Impact or Armageddon and its immediately clear that there would be devastation at the impact site and around it, it happens just extremely infrequently to cause widespread damage.
While an asteroid impact has been visualized in movies like Deep Impact or Armageddon and its immediately clear that there would be devastation at the impact site and around it, it happens just extremely infrequently to cause widespread damage.
13/15
On the other hand, the effects of a strong solar storm by leading to power blackouts and cutting us off from online resources would touch an Achilles heel of our society that works much more subtle than a rock from space hitting the ground at very high speed.
On the other hand, the effects of a strong solar storm by leading to power blackouts and cutting us off from online resources would touch an Achilles heel of our society that works much more subtle than a rock from space hitting the ground at very high speed.
14/15
The bottom line:
A hazardous solar storm, leading to considerable societal disruption over larger regions through power blackouts, is highly likely to impact Earth in the next 100 years. An asteroid with similar consequences may occur every 100 000 to 1 million years.
The bottom line:
A hazardous solar storm, leading to considerable societal disruption over larger regions through power blackouts, is highly likely to impact Earth in the next 100 years. An asteroid with similar consequences may occur every 100 000 to 1 million years.
15/15
This week @esa is going forward with a big decision on the #LagrangeMission which could give us a decisive advantage in the real time prediction of solar storms, by observing from the L5 point with many different instruments from the mid 2020s onwards.
Fingers crossed!
This week @esa is going forward with a big decision on the #LagrangeMission which could give us a decisive advantage in the real time prediction of solar storms, by observing from the L5 point with many different instruments from the mid 2020s onwards.
Fingers crossed!
