Astronomers say a new molten planet identified beyond our solar system may represent an entirely different category of world—one where oceans are not made of water, but of blazing magma.

The distant planet, L98-59d, appears to be a seething sphere of liquid rock. Scientists say its discovery hints that the universe may host a broader variety of planets than previously imagined.

Orbiting a small red dwarf star roughly 35 light-years away, the planet is about 1.6 times the size of Earth. Early observations led astronomers to suspect it might harbor a deep global ocean. But new research paints a far more dramatic picture—one of a world simmering like a cosmic cauldron.

A Planet That Behaves Like Molten Molasses

Researchers now believe the planet could exist almost entirely in a molten state.

“The whole thing really is in a mushy, molten state,” said Harrison Nicholls, describing the world as resembling thick, flowing molasses. “It’s likely that this planet’s core would also be molten.”

Temperatures on the planet’s surface are estimated to soar to around 1,900 degrees Celsius (3,500 degrees Fahrenheit). At such extremes, rock melts and churns like lava in a planetary-scale furnace.

Massive waves of magma may ripple across the planet’s surface, driven by gravitational tugs from neighboring planets. Meanwhile, the atmosphere could carry the unmistakable odor of rotten eggs due to high levels of hydrogen sulphide gas.

Those conditions make the planet extremely hostile to life.

“If there are aliens out there that could live in lava that would be amazing,” Nicholls said. “But I don’t think it’s likely that it’s habitable.”

How Scientists Peered Into a Distant Alien World

Planets outside our solar system are far too distant to photograph directly or reach with spacecraft. For decades, astronomers relied on indirect measurements—tracking tiny dips in starlight as planets passed in front of their stars.

But powerful new instruments are changing that.

Using the James Webb Space Telescope, scientists can analyze starlight filtered through a planet’s atmosphere. This method reveals the chemical fingerprints of gases surrounding distant worlds.

Earlier observations showed that L98-59d possesses a sulphur-rich atmosphere. That discovery puzzled researchers because planets of similar size are usually classified as either rocky Earth-like worlds or water-covered ocean planets.

Neither category could explain how such an atmosphere could survive for nearly five billion years.

Simulations Reveal a Deep Magma Ocean

To unravel the mystery, scientists ran advanced computer simulations reconstructing the planet’s history from its birth to the present.

The results suggest L98-59d contains a massive global magma ocean stretching thousands of kilometers below the surface—possibly reaching a molten core.

“You can only really explain this planet if it has this deep magma ocean inside of it,” Nicholls explained.

That ocean of molten rock may act like a giant storage system for gases, trapping them and protecting them from processes that would otherwise strip the atmosphere away.

A Warning About ‘Habitable’ Worlds

The discovery could reshape how astronomers evaluate planets that appear potentially habitable.

Nicholls cautioned that some planets located in the so-called habitable zone—the region where liquid water could exist—may not be Earth-like at all.

“Some planets in the habitable zone might not be very habitable,” he said. “They might actually be these molten planets.”

While L98-59d is unlikely to support life, its existence highlights the extraordinary diversity of worlds scattered across the galaxy.

Even More Extreme Than Volcanic Worlds

Planetary scientist Jo Barstow, who helped observe the planet with the James Webb telescope, said earlier theories suggested the planet might resemble Io, famous for its intense volcanic activity.

But the latest analysis suggests something even more extreme.

“We talked about it possibly being an exoplanet that resembles Io, with lots of volcanoes caused by tidal heating,” Barstow said. “This work suggests it could be even more extreme.”

A Universe Full of Strange Worlds

The findings, published in the journal Nature Astronomy, hint that molten worlds like L98-59d could be more common than scientists once believed.

If so, the discovery of this new molten planet identified may represent only the first glimpse into a vast population of fiery alien worlds.

And as astronomers continue scanning the cosmos, one question lingers: what other planetary oddities are still waiting to be discovered?