WASHINGTON — Mars has just become the first "other" planet to have its internal structure accurately measured by human seismology sensors.
This is the first time humans have managed to directly map the internal layering of a planet other than Earth.
The data surprised NASA's scientists and helped them to understand a lot more about how Mars formed and cooled.
The BBC reports that NASA scientists have studied data from the seismology sensors on its InSight probe and now know what the internal structure of Mars looks like.
The probe has been sensing small quakes on the planet since early 2019. Its readings reveal that Mars' crust is between 24 and 72 kilometers thick, which is thinner than expected.
But the key finding is the size of the planet's liquid and metallic core. Its radius of 1,830 kilometers is wider than expected.
This means that the mantle between the core and the crust is thinner than previously thought. And that means it's highly unlikely this mantle can achieve the pressures where the mineral bridgmanite becomes stable.
On Earth, this stiff mineral blankets the core, slowing convection and the loss of heat. On early Mars, its absence would have led to rapid cooling.
This initially would have permitted strong convection in the metal core, which drove a global magnetic field. But because of rapid cooling, this has now switched off and today Mars has no global magnetic field.
If Mars did have a global magnetic field, it would have provided some shielding to protect its surface from the damaging radiation that constantly rains down from space, making the planet extremely inhospitable.
Earth's rare magnetic field is one of the many amazing reasons why life is possible on Earth.
