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  • 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 fieldwhich shields Earth from

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

  • Unlike Earth, Mars doesn't have a dynamoand as a result, no intrinsic magnetic field

  • to stop charged particles from stripping away its atmosphere.

  • But this wasn't always the case.

  • 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

  • into a cold, inhospitable desert.

  • 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

  • in its southern hemisphere.

  • 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

  • calledsputtering.”

  • 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

  • and figure out how old they are.

  • 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 worksThe 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 aloneAlong 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.

  • Venus doesn't have one either!

  • 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?

  • Let us know down in the comments below.

  • Make sure to subscribe and thanks so much for watching.

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

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