doi.org/10.1038/s41550-025-02729-x
Credibility: 959
#Exoplanet
Deep within some giant rocky planets, called super-Earths, lie vast layers of molten rock that may be creating powerful magnetic fields
These hidden “oceans” of magma act as an invisible shield, protecting the planet from cosmic radiation and high-energy particles that could destroy any life on the surface.
Here on Earth, the magnetic field that protects us arises from the movement of liquid iron in the planet’s outer core, a process known as dynamo.
However, on super-Earths-planets larger than Earth but smaller than Neptune-things may be different.
Their cores may be entirely solid or completely liquid, making it difficult to generate a magnetic field using the same mechanism we use here.
Researchers at the University of Rochester have discovered a surprising solution: a deep layer of magma called a basal magma ocean.
In a study published in the journal “Nature Astronomy,” they show that this molten rock, under extreme pressure, can conduct electricity and generate a long-lasting magnetic dynamo.
Miki Nakajima, associate professor and one of the authors of the work, explains that a strong magnetic field is essential for life.
Without it, planets like Venus and Mars have lost much of their atmospheres and water.
Super-Earths, being more common in the galaxy and frequently located in the habitable zone (where water can exist in liquid form), have a greater chance of harboring life if they manage to maintain this protective shield.
The scientists simulated the extreme conditions inside these planets using shock laser experiments at the university’s Laser Energetics Laboratory, combined with computer simulations.
The results revealed that, on planets more than three to six times the size of Earth, the deep magma can remain conductive for billions of years, producing magnetic fields even stronger and more stable than Earth’s.
This changes how we think about the habitability of exoplanets.
In the past, Earth itself may have had a similar layer of basal magma, which influenced its development.
In super-Earths, because of the greater internal pressure, this layer tends to last much longer, helping to keep the planet warm inside, regulate heat, and, most importantly, create a magnetic field that protects life.
This discovery opens new doors for the search for life outside the Solar System.
When future telescopes manage to measure the magnetic fields of distant exoplanets, we will be able to test this hypothesis.
Meanwhile, researchers continue to combine physics, geology, and astronomy to better understand how these gigantic worlds work.
In short, hidden oceans of magma are not just geological curiosities: they may be the key to giant rocky planets becoming safe havens for alien life forms.
An idea that expands our imagination about where life might exist in the universe.
Published in 04/14/2026 03h10
Text adapted by AI (Grok) and translated via Google API in the English version. Images from public image libraries or credits in the caption. Information about DOI, author and institution can be found in the body of the article.
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