Study Findings: Building Wet Planets Through High-Pressure Magma–Hydrogen Reactions

Posted on by onespaceman2000
Credit: Image by Yol Gezer from Pixabay

Nature abstract of study findings:

Close-in transiting sub-Neptunes are abundant in our Galaxy. Planetary interior models based on their observed radius–mass relationship suggest that sub-Neptunes contain a discernible amount of either hydrogen (dry planets) or water (wet planets) blanketing a core composed of rocks and metal. Water-rich sub-Neptunes have been believed to form farther from the star and then migrate inwards to their present orbits. Here we report experimental evidence of reactions between warm, dense hydrogen fluid and silicate melt that release silicon from the magma to form alloys and hydrides at high pressures. We found that oxygen liberated from the silicate melt reacts with hydrogen, producing an appreciable amount of water up to a few tens of weight per cent, which is much greater than previously predicted based on low-pressure ideal gas extrapolation. Consequently, these reactions can generate a spectrum of water contents in hydrogen-rich planets, with the potential to reach water-rich compositions for some sub-Neptunes, implying an evolutionary relationship between hydrogen-rich and water-rich planets. Therefore, detection of a large amount of water in exoplanet atmospheres may not be the optimal evidence for planet migration in the protoplanetary disk, calling into question the assumed link between composition and planet formation location.

Citation: Horn, H.W., Vazan, A., Chariton, S. et al. Building wet planets through high-pressure magma–hydrogen reactions. Nature 646, 1069–1074 (2025).

https://doi.org/10.1038/s41586-025-09630-7

Study-related stories:

Science News – “Some Planets Might Home Brew their Own Water”

Universe Today – “Some Exoplanets Can Create Their Own Water Through Crust-Atmosphere Reactions”

Space Daily – “Water Production on Exoplanets Revealed by Pressure Experiments”

Pic of the Week: Another View of the Milky Way

Posted on by onespaceman2000
Image (Credit): The Milky Way galaxy in radio waves as seen from the Southern Hemisphere. (Silvia Mantovanini and the GLEAM-X Team)

The image above was released late last year. It shows the Milky Way galaxy in radio-color captured by astronomers from the International Centre of Radio Astronomy Research (ICRAR). All of this was part of the GaLactic and Extragalactic All-sky MWA (GLEAM) and GLEAM-X (GLEAM eXtended) surveys conducted over 28 nights in 2013 and 2014 as well as 113 nights from 2018 to 2020.

In describing the image, Silvia Mantovanini, one of the astronomers analyzing the survey data, noted:

You can clearly identify remnants of exploded stars, represented by large red circles. The smaller blue regions indicate stellar nurseries where new stars are actively forming.

In this video, you can hear more from astronomers Silvia Mantovanini and Natasha Hurley-Walker who co-wrote a paper on this work titled GaLactic and extragalactic all-sky Murchison Widefield Array survey eXtended (GLEAM-X) III: Galactic plane.

Study Findings: A Binary Model of Long-Period Radio Transients and White Dwarf Pulsars

Posted on by onespaceman2000
Credit: Casey Reed, NASA

Nature Astronomy abstract of study findings:

Long-period radio transients (LPTs) represent a recently uncovered class of Galactic radio sources exhibiting minutes to hours periodicities and highly polarized pulses of seconds to minutes duration. Their phenomenology does not fit exactly in any other class, although it might resemble that of radio magnetars or white dwarf (WD) pulsars. Two LPTs with confirmed multi-wavelength counterparts have now been identified as WD – M dwarf binaries. Moreover, WD pulsars (also WD – M dwarf systems), such as AR Scorpii and J1912−44, are known to exhibit short-period pulsations in hour-timescale orbits. Here we investigate the longest-lived LPT known, GPM J1839−10. We use a 36-year timing baseline to infer an ~8.75-h orbital period from radio data alone, and we show that it can be modelled in the same geometric framework as has been proposed for WD pulsars. Radio emission is triggered when the magnetic axis of a rotating WD intersects the wind from its companion, which naturally predicts the peculiar pulse modulation. Applying this to the WD pulsar J1912−44 successfully reproduces the emission profile and geometry as well. Our results indicate analogous emission-site geometries in these related classes of binary system, a possibility we extend to the broader LPT and WD pulsar population.

Citation: Horváth, C., Rea, N., Hurley-Walker, N. et al. A binary model of long-period radio transients and white dwarf pulsars. Nat Astron (2026).

https://doi.org/10.1038/s41550-025-02760-y

Study-related stories:

The Conversation – “Puzzling Slow Radio Pulses are Coming from Space. A New Study Could Finally Explain Them”

The Institute of Space Studies of Catalonia – “A Binary Star System Explains Mysterious Radio Pulses Across the Milky Way”

Sci.News – “Sporadic Radio Pulses Traced to White Dwarf-Red-Dwarf Binary System”

Study Findings: Electrical Conductivities of (Mg,Fe)O at Extreme Pressures and Implications for Planetary Magma Oceans

Posted on by onespaceman2000
Image (Credit): Artist’s rendering of deep layers of molten rock inside a super-earth generating powerful magnetic fields. (University of Rochester Laboratory for Laser Energetics illustration / Michael Franchot)

Nature Astronomy abstract of study findings:

During planet formation, planets undergo many impacts that can generate magma oceans. When these crystallize, part of the magma densifies via iron enrichment and migrates to the core–mantle boundary, forming an iron-rich basal magma ocean (BMO). The BMO could generate a dynamo in early Earth and super-Earths if the electrical conductivity of the BMO, which is thought to be sensitive to its Fe content, is sufficiently high. To test this hypothesis, here we conduct laser-driven shock experiments on ferropericlase (Mgx,Fe1−x)O (0.95 ≤ x ≤ 1) as an Fe-rich BMO analogue, perform density functional theory molecular dynamics simulations on MgO and calculate the long-term evolution of super-Earths. We find that the d.c. conductivities of MgO and (Mg,Fe)O are indistinguishable between 467 GPa and 1,400 GPa, despite previous predictions. We predict that super-Earths larger than 3–6 Earth masses can produce BMO-driven dynamos that are almost one order of magnitude stronger than core-driven dynamos for several billion years.

Citation: Nakajima, M., Harter, S.K., Jasko, A.V. et al. Electrical conductivities of (Mg,Fe)O at extreme pressures and implications for planetary magma oceans. Nat Astron (2026).

https://doi.org/10.1038/s41550-025-02729-x

Study-related stories:

University of Rochester – “Hidden Magma Oceans Could Shield Rocky Exoplanets from Harmful Radiation”

Earth Sky – “Powerful Magnetic Fields on Super-Earths Could Boost Chances of Life”

Universe Today – “Deep Magma Oceans Could Help Make Super-Earths Habitable”

Study Findings: A Carbon-rich Atmosphere on a Windy Pulsar Planet

Posted on by onespaceman2000
Image (Credit): Artist’s rendering of of an exoplanet orbiting a rapidly spinning neutron star called a pulsar. (NASA, ESA, CSA, Ralf Crawford (STScI))

Abstract of pre-publication study findings:

A handful of enigmatic Jupiter-mass objects have been discovered orbiting pulsars. One such object, PSR\,J2322-2650b, uniquely resembles a hot Jupiter exoplanet due to its minimum density of 1.8 g/cm^3 and its ~1900 K equilibrium temperature. We use JWST to observe PSR J2322-2650b’s emission spectrum across an entire orbit. In stark contrast to every known exoplanet orbiting a main-sequence star, we find an atmosphere rich in molecular carbon (C3, C2) with strong westward winds. Our observations open up new exoplanetary chemical (ultra-high C/O and C/N ratios of >100 and >10,000, respectively) and dynamical regimes (ultra-fast rotation with external irradiation) to observational study. The extreme carbon enrichment poses a severe challenge to the current understanding of “black widow” companions, which were expected to consist of a wider range of elements due to their origins as stripped stellar cores.

Citation: Michael Zhang et al. A carbon-rich atmosphere on a windy pulsar planet. ApJL (2025).

https://doi.org/10.48550/arXiv.2509.04558

Study-related stories:

University of Chicago – “NASA’s Webb Telescope Finds Bizarre Atmosphere on a Lemon-shaped Exoplanet”

Scientific American – “This Planet Is the Shape of a Lemon. That May Be the Least Weird Thing about It”

Space Daily – “Webb Maps Carbon Rich Atmosphere on Distorted Pulsar Planet”