Liquid planet discovered by astronomers as L98-59d reveals molten surface

Published: 16 March 2026. The English Chronicle Desk. The English Chronicle Online.

The vast expanse of our universe continues to challenge every traditional understanding of planetary formation and cosmic structure. Deep within the constellations of the southern sky, astronomers have recently uncovered a world that defies conventional scientific labels. This distant world, known as L98-59d, has provided the first tangible evidence for a liquid planet category. Rather than a solid rocky surface or a deep water ocean, this planet exists in a state of perpetual flux. It represents a breakthrough in our understanding of how planets evolve under extreme gravitational and thermal conditions. Scientists now believe that L98-59d is not merely a volcanic wasteland but a fully integrated molten sphere.

The initial discovery of this celestial body suggested a far more familiar environment to the research teams involved. Early observations led many to believe that the planet might harbour a deep and massive liquid water ocean. Such a feature would have placed it high on the list of potential candidates for extraterrestrial life. However, the latest data sets have painted a much more volatile and fascinating picture of the distant world. The planet is roughly one point six times the size of our own Earth. It orbits a small red dwarf star located approximately thirty-five light years away from our solar system. This proximity allows for detailed study that remains impossible for many other far-flung star systems today.

Dr Harrison Nicholls is an astrophysicist at the University of Oxford who has closely studied the new data. He describes the planet as being in a constant mushy and molten state across its entire surface. The consistency of the planetary material is frequently compared to thick molasses moving slowly under intense heat. This state is not limited to the surface crust but likely extends deep into the interior. Research suggests that even the core of this massive world remains in a liquid form. Such a discovery shifts the focus of planetary science toward a new classification of liquid planet types. This means the transition from crust to core is a gradient of heat rather than solid layers.

The environmental conditions on L98-59d are nothing short of hellish by any human or biological standard. Surface temperatures on the planet are estimated to reach a staggering nineteen hundred degrees Celsius at any time. These temperatures are high enough to melt almost any rock or mineral known to exist on Earth. Because of this heat, the entire globe is covered by a shifting and churning magma ocean. Large waves of molten rock are thought to roll across this sea with immense destructive power. These waves are caused by the tidal forces exerted by neighbouring planets in the same system. The gravitational tug of war keeps the interior of the planet constantly agitated and incredibly hot.

A human observer would find the atmosphere of this liquid planet to be equally hostile and strange. There is a pervasive and overwhelming stench of rotten eggs that hangs over the entire landscape. This smell is the result of an atmosphere that is incredibly rich in hydrogen sulphide gas. Such a chemical composition is a direct byproduct of the constant volcanic activity on the surface. While some might hope for life, Dr Nicholls remains very sceptical about any biological potential here. He notes that while aliens living in lava would be amazing, it is highly unlikely. Instead, scientists are choosing to marvel at the sheer alien nature of the environment itself.

For many years, our ability to study planets outside our solar system was limited by technological constraints. We could only make crude estimates based on the silhouettes of planets passing in front of stars. These methods gave us a rough idea of size and density but little else. The deployment of the James Webb Space Telescope has changed the landscape of astronomy forever. This powerful instrument can measure starlight as it filters through a distant planet’s thin atmosphere. By doing so, it provides a chemical readout of the gases that are present there. This allows scientists to determine the composition of a world without ever having to visit it.

In the case of L98-59d, these observations revealed a sulphur-rich atmosphere that puzzled the initial research teams. This chemical signature did not match the profile of a rocky world or a water world. For a planet to keep a sulphur atmosphere for five billion years, something must replenish it. Neither a solid crust nor a cold ocean could sustain such a volatile chemical balance over time. The only logical explanation was a constant source of outgassing from a deep, molten interior source. This led to the creation of advanced computer simulations to model the history of the world. These models confirmed that a liquid planet model was the only one that fit the data.

The simulation results suggest that the magma ocean on L98-59d extends thousands of kilometres deep into the planet. This vast reservoir of molten material acts as a storage system for various atmospheric gases. The magma protects these gases from physical processes that would usually strip them away into space. This efficient storage explains why the sulphur levels remain so high after billions of years of existence. It also suggests that this liquid planet might be far more common than we once believed. If other stars have similar tidal heating, many “rocky” planets might actually be molten spheres.

This realization has significant implications for our search for habitable worlds and the famous “Goldilocks zone.” Some planets that sit at the right distance from their star might still be completely uninhabitable. If tidal forces are strong enough, they can turn a temperate world into a molten furnace. This discovery serves as a reminder to be cautious when we label a new world as Earth-like. The diversity of worlds beyond our solar system is much wider than our previous models suggested. We are now entering an era where we must look for specific geological stability in our targets. A liquid planet can look very similar to a rocky one from a great distance.

Dr Jo Barstow, a planetary scientist at the Open University, has also been involved in these groundbreaking observations. She noted that the team had previously compared the planet to Jupiter’s moon, known as Io. Io is the most volcanically active body in our own solar system due to extreme tidal heating. However, the latest findings suggest that L98-59d is an even more extreme version of that environment. It is not just a world with many volcanoes but a world that is a single volcano. This makes it a primary example of how gravity can shape the physical state of matter.

The full details of this research have been published in the prestigious journal Nature Astronomy this month. The scientific community is now looking for other candidates that might fit into this new liquid category. By identifying the specific traits of a liquid planet, we can better filter our search for true alien life. Every new world we find provides a piece of the puzzle regarding our own place in space. While L98-59d may be a place of fire and stench, it is a beautiful example of cosmic variety. The search for knowledge continues as we look deeper into the dark reaches of our galaxy.

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