Name: This Map Could Provide the Missing Clue to How Mars Became Inhospitable
Uploaded: 2020-08-05T19:10:32.000Z
Duration: 5 min 2 s
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Modal verbs of deduction & speculation

You may have heard that Mars doesn't have a magnetic field. But that's not true!

Now, thanks to data from NASA's MAVEN satellite,

researchers at the University of Colorado, Boulder

have created the very first detailed map of the electric currents responsible for shaping

the magnetic field that wraps around Mars.

Not only are the visualizations stunning,

but they provide clues of how we can make this inhospitable planet one we can live on...maybe.

Let's start with what we know so far. The region of space around a planet that's

dominated by that planet's magnetic field is known as its magnetosphere.

Earth's magnetosphere is driven by an internal dynamo,

a rotating mass of molten iron that's located in our planet's outer core.

The energy generated by the rising, cooling, and sinking of that molten iron

gets converted into a powerful magnetic field, which shields Earth from

the charged particles of solar and cosmic radiation and protects our atmosphere.

Unlike Earth, Mars doesn't have a dynamo — and as a result, no intrinsic magnetic field

to stop charged particles from stripping away its atmosphere.

Turn back the clock to about 4.3 billion years ago and Mars might have looked a lot more Earth-like.

It had a thick atmosphere and warm climate

capable of sustaining bodies of water like rivers, lakes, and even oceans!

All of this would have been possible if Mars once had a working dynamo  of its own to protect its atmosphere.

But somehow, Mars transformed from a warm and wet place

There are a couple of leading theories as to what might have caused this dramatic transformation.

Some scientists believe that a series of giant asteroid impacts bombarded Mars over a period

of 100 million years. The idea goes that these impacts overheated the planet's mantle

and stopped the dynamo, effectively killing off the planet's intrinsic magnetic field.

Certain evidence suggests that Mars might have had a dynamo in only a single hemisphere.

And in fact, missions to the red planet have found remnants of a stronger magnetic field

With a lopsided energy field, the planet's atmosphere

would have been left vulnerable to erosion from the solar wind,

allowing it to collide with atoms in the upper atmosphere and eject them into space through a process

As its atmospheric gas was slowly stripped away,

Mars' atmosphere eventually became depleted enough to transform the planet into a cold, arid place.

Today, signs of Mars' ancient intrinsic magnetic field still exist.

Since 2018, NASA's InSight lander has been on the ground measuring the strength and direction

of the planet's magnetic field and collecting detailed measurements of magnetic fields in the crust.

Because most of the rocks at Mars' surface

are too young to have been magnetized by the planet's former field, scientists speculate

that the sources of these crustal magnetic fields are rocks buried deep underground.

Located anywhere from a couple of hundred meters to several kilometers below the ground,

these older rocks formed before the planet's dynamo shut down and remain magnetized,

acting as local mini-magnetospheres today.

By combining the measurements collected by InSight with satellite data,

researchers hope to identify exactly which rocks carry magnetism

While on the ground, InSight has also recorded

mysterious fluctuations in the strength and direction of the magnetic field between day and night.

Here's how it works. The charged particles that make up the solar wind are

highly conductive, inducing electric currents that shape how energy flows into Mars' atmosphere.

These currents cause a 'pile-up' of the magnetic field in the planet's upper atmosphere,

until they become strong enough to create an induced magnetosphere.

By analyzing five years of data from MAVEN, researchers were able to piece together the

electric current systems in Mars' atmosphere.

The initial results show how these electric currents

interact with the solar wind, causing it to wrap around the planet and form an induced

magnetosphere that offers Mars some protection.

Because while MAVEN and other previous missions

have seen hints of these currents before, this is the first time we've been able to map the complete circuit.

MAVEN's goal is to explore the upper atmosphere,

and it's not alone. Along with five other current Mars missions,

it's trying to understand the potential for life to exist on Mars.

If we ever plan to put boots down on the red planet,

we'll need to understand how important a magnetic field is for regulating climate.

Because while this work won't bring back Mars' thick atmosphere,

it may help us determine if Mars ever hosted life and if it could again.

Mars isn't the only misfit without an intrinsic magnetic field.

If you wish you had an interplanetary zip code of your own,

why not check out this video on terraforming Venus and Mars!

Is there any cool space phenomena you'd like to see us cover?

Make sure to subscribe and thanks so much for watching.