Super-Earths might be solid deep on the inside

Super-Earths might be solid in their deep insides, a new study says. Minerals might take unusual forms and remain solid despite the intense heat and pressure. The science-journalism coverage adds useful context, while the strongest evidential footing still comes from the underlying data, papers or institutional documentation.

The significance lies in exoplanet science has moved beyond the era of simple discovery into a period of comparative characterization. With more than five thousand confirmed planets known, the scientifically productive questions now concern atmospheric composition, internal structure, orbital history and the statistical properties of populations rather than the existence of individual worlds. A new detection or spectral measurement is most valuable when it adds a well-constrained data point to those comparative frameworks, not when it stands alone as an anecdote. It orbits a red dwarf star 98 light-years from Earth. Now, a new study from researchers at Princeton University in New Jersey suggests something surprising.

The researchers found these minerals could likely withstand the extremely high temperatures and pressures deep inside super-Earths, much hotter than inside Earth, and remain solid. Nathaniel Scharping wrote about the new findings for Eos on August 6, 2026.

The researchers published their peer-reviewed paper in AGU Advances on July 18, 2026. | Illustration depicting the size of a super-Earth called CoRoT-7b.

At even higher pressures, this phase breaks down into two different minerals: bridgmanite, the most abundant mineral phase in Earth, and ferropericlase, a magnesium-rich oxide. However, under the far more extreme pressures expected inside massive rocky planets known as super-Earths, Mg2SiO4 becomes stable again in an entirely new crystal structure called.

The broader interest lies in making the target less anecdotal and more comparable with the rest of the known planetary population. Population-level questions, such as the frequency of atmospheres around small rocky planets or the prevalence of water-rich worlds in the habitable zone, require well-characterized individual data points before statistical patterns become meaningful. Each new planet with a measured radius, mass and, ideally, atmospheric constraint is a brick in that larger structure, and the accumulation of bricks eventually allows theorists to test formation models against real distributions rather than projections.

Scientists predict that this ultrahigh-pressure phase of Mg2SiO4 is one of the dominant minerals in the deep mantles of super-Earths, making its melting behavior important for. | This is an artist’s concept of a super-Earth with a deep magma ocean generating a magnetic field.

Because this item comes through EarthSky as science journalism, it should be treated as contextual reporting rather than primary evidence. Good science reporting can identify why a result matters, connect it to the wider literature and make technical work readable, but the decisive evidence remains in the original paper, dataset, mission release or technical record. That distinction is especially important when a story is later repeated by aggregators, because repetition increases visibility, not evidential strength.

The next step is to improve independent constraints on the mass, radius, atmospheric composition and orbital dynamics of the target. Transmission spectroscopy with JWST, radial velocity campaigns with high-resolution ground-based spectrographs and phase-curve measurements from space photometry represent the observational toolkit that can move characterization from plausible to robust. That convergence of techniques is the standard the community now expects before a planetary atmosphere result is treated as confirmed.

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