Hey Crazies.
I have received a challenge.
So I’ve been thinking some crazy thoughts and, that is, what would it take to artificially
generate a magnetic field strong enough to protect the Martian atmosphere?
And that requires some crazy physics, so where else do you go but the craziest people in
physics and, that is, in the Science Asylum.
You know, Phillip, if we do this right, it might not actually be as crazy as it sounds.
First, let me explain the problem with Mars.
It has a really thin atmosphere and it's very cold.
It ranges from about 400 pascals up to about 900 pascals.
That’s pretty low compared to Earth’s atmosphere.
Temperatures aren’t any better.
They range from about -130 degrees Fahrenheit only up to about -20 degrees Fahrenheit
It’s basically an ice planet.
The atmosphere is also 95% carbon dioxide and there is no liquid water on the surface.
As you can see from this fancy phase-diagram, liquid water is physically impossible under
Mars’s normal conditions.
Anyway, none of this is great for humans.
I mean, your eyes aren’t going to pop out of your face or anything, but it will definitely
kill you and quickly.
It wasn’t always like this though.
As Phillip mentioned: When it comes to terraforming Mars, one of
the major problems is the fact that Mars has a very thin atmosphere because it has essentially
no magnetic field.
Back in the day, it had a magnetic field, which means it had a thicker atmosphere, which
means it had liquid water on its surface.
It’s just that about 4.2 billion years ago, the magnetic field turned off, the atmosphere
stripped away, and the water either froze or evaporated.
And as Phillip pointed out: If we go through all this effort of generating
an atmosphere, we don’t want it to be blown away by the solar wind.
Which, you know, sounds reasonable.
Let’s do this!
But Mars doesn’t have the gravity of Earth, so it can’t...
You’re right. You’re right.
We’ll deal with that first.
There’s another problem with Mars.
It only has about 38% of Earth’s surface gravity.
The upside?
You can jump 2.6 times as high.
The downside?
It can only hold on to about 38% as much atmosphere as Earth.
We can’t fix the surface gravity problem, so the highest the pressure could ever get
is 0.38 atmospheres.
That’s roughly the pressure near the peak of Mt Everest.
It’s not enough to walk around outside without an oxygen mask, but it’s definitely enough
to get some liquid water.
Now let’s do this!
OK, let’s see.
Elon Musk wants use nukes.
We’d have to drill down to the Martian core and detonate the nukes there.
That would re-liquefy the core and get it moving again.
But that seems like a lot of energy.
Considering the core’s current temperature and pressure, which would give us a density,
specific heat, and latent heat.
Allowing us to calculate mass and, ultimately, thermal energy, which comes to approximately
10 to the 29 joules!
That’s about 10 trillion megatons or 100s of billions of the largest nuke ever created.
I don’t think this is going to work.
Even if we could manage to do this somehow, there’s no guarantee the liquid core would
actually generate a magnetic field.
and, even then, we’d have to keep the core from cooling off again.
We need a better option.
Hmm.
I’ve got it.
Who says this magnetic field has to be created by the planet or even on the planet?
Let’s just put a big magnet in space.
Unfortunately, we can't just put this thing into orbit around Mars because we need it to always be
between Mars and the Sun.
We need a Lagrange point.
There are 5 points in and around a circular orbit that are stable.
Other objects can sit in them and they’ll all orbit together.
Any deviation and the object gets tugged back into place.
They’re very useful for human-made probes.
For our space magnet, L1 will do quite nicely.
L1 for Mars is about 160 Mars’s away from Mars.
That looks something like this.
It’s really far away.
So we’d need it to be strong enough that Mars would still be inside of it.
Which isn’t actually that difficult.
Earth’s magnetic field is only about 30-60 microteslas and the Moon is inside it.
Remember how far away the Moon is?
This I don’t even need to calculate because NASA scientists already did it!
Dr. Jim Green and a team of planetary scientists ran computer simulations for a space magnet at L1.
According to them, a magnet anywhere from 50-500 microteslas should do the trick.
We can easily generate that with current technology.
If we did this, Mars’s atmosphere would thicken over time on its own because it’s
not getting blasted away by the solar wind.
The northern polar ice cap is a bunch frozen water covered in a thin layer of dry ice.
As the atmosphere thickens, the temperature will rise, and that ice cap will melt.
First, the dry ice, releasing more CO2, a known greenhouse gas.
This will speed up the warming process even more, which will help melt the frozen water
underneath.
Eventually, liquid water would be able to flow on the surface.
As much as 1/7 of Mars’s ancient ocean could come back, making Mars look like it did in
the good-old-days.
Again, there still won’t be enough pressure to, you know, breath, but it’ll make colonizing
Mars a heck of a lot easier.
So I’ve got one thing to say to you NASA: Get your [crow noise] to Mars.
Got any questions about Mars?
Please ask in the comments.
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And until next time, remember, it’s OK to be a little crazy.
The featured comment comes from Bill DeWitt, who suggested an alternate name for Spin:
Aim!
Angular Intrinsic Momentum.
It's aimed up or down.
You know.
That’s not bad!
I think I’ll propose it at the next Science Insanity Meeting.
Anyway, thanks for watching!