Scientists have finally uncovered evidence that Mars may have a solid inner core.
The findings, published in Nature, are based on seismic data collected by NASA’s InSight lander, which operated on the Martian surface from 2018 until late 2022. For years, scientists believed Mars had only a liquid core, but new analysis suggests it also contains a solid inner core – similar to Earth’s.
The discovery helps answer a major question about the planet – whether it once had a magnetic field like Earth’s, and what caused it to disappear. It comes after NASA made a staggering alien discovery close to Earth.
“The very presence of a solid inner core shows that crystallization and solidification is taking place as the planet cools over time,” said lead researcher Huixing Bi from the University of Science and Technology of China.
The magnetic field on Earth is created by movement in the liquid outer core, which surrounds a solid inner core.
This magnetic field protects the planet by deflecting solar particles and preserving the atmosphere. Mars, by contrast, lost its magnetic field long ago – likely leading to the gradual loss of its atmosphere and surface water.
However, signs of a magnetic field in Mars’ ancient crust suggest it once had such a protective system. Scientists have debated for decades whether the planet’s interior ever resembled Earth’s.
NASA’s InSight lander helped answer that question by using seismometers to measure “Marsquakes.”
In 2021, researcher Simon Stähler and his team first confirmed Mars has a liquid core. However, at the time, there was no strong evidence of a solid layer inside it.
Stähler’s model showed a single liquid core, with elements like carbon, sulphur, and hydrogen, that lower the core’s melting point and help it stay liquid.
However, the new study goes a step further by using refined data analysis techniques and focusing on specific seismic signals, Bi and colleagues detected a solid inner core with an estimated radius of 610 km.
“This result makes it more likely that a dynamo on Mars was possible in the past,” the researchers shared.