A new study has confirmed that Mars has an inner core, making it the only planet besides Earth known to have this feature. Using seismic data from NASA’s InSight lander, scientists discovered that Mars’ solid inner core is wrapped in a molten outer core—revealing striking similarities to Earth’s structure.
The Discovery
The breakthrough comes from research led by Sun Daoyuan at the University of Science and Technology of China. Scientists analyzed seismic waves from 23 marsquakes, detecting how they traveled through the planet’s interior.
- The solid inner core measures about 380 miles (613 km) in radius.
- It is surrounded by a liquid outer core that extends nearly 1,100 miles (1,800 km).
- The composition includes iron, nickel, sulfur, oxygen, and carbon.
This marks the first confirmed inner core detection in another planet beyond Earth.
Why It Matters
Similar to Earth
Like Earth, Mars’ inner core makes up about one-fifth of the planet’s total radius. This suggests similar processes shaped their early histories.
Clues to Lost Magnetism
Billions of years ago, Mars had a global magnetic field. Scientists believe its layered core structure could explain how Mars once generated—and then lost—this protective shield.
A First Beyond Earth
This is the first time scientists have confirmed a solid inner core on another planet, a huge step for planetary science.
Limitations of the Study
- The findings are based on limited seismic data—only 23 weak marsquakes.
- More instruments and missions are needed to refine details about the core’s shape and density.
Still, experts call this a milestone in exploring Mars’ deep interior.
Quick Facts Table
| Feature | Details |
|---|---|
| Inner Core | Solid; radius ~380 miles (613 km) |
| Outer Core | Liquid; extends ~1,100 miles (1,800 km) |
| Composition | Iron–nickel alloy + sulfur, oxygen, carbon |
| Similarity to Earth | Inner core ~1/5 of planet radius |
| Significance | First confirmed solid inner core beyond Earth |
Conclusion
The discovery that Mars has an inner core confirms the Red Planet’s internal structure is more Earth-like than once believed. It not only deepens our understanding of Mars’ past but also provides crucial insights into planetary formation across the solar system.
