Lava Planet Keeps Its Atmosphere With Giant Sunscreen

A planet covered in molten rock shouldn't have an atmosphere, yet one of the most extreme worlds ever discovered is doing exactly that.

Astronomers using the James Webb Space Telescope found that TOI-561 b, a lava world 280 light-years from Earth, has kept its atmosphere despite conditions that should have stripped it away billions of years ago. The planet orbits so close to its star that its surface churns with oceans of molten rock and temperatures soar beyond anything imaginable.

The team, including Dr. Anjali Piette from the University of Birmingham, watched the planet complete nearly four full orbits over 37 hours. What they discovered surprised everyone: TOI-561 b reflects about 75% of the starlight hitting it, roughly the same as Venus.

The secret appears to be clouds made of silicate minerals floating above the lava ocean. These clouds contain silicon dioxide and magnesium silicate, the same materials found in common rocks on Earth. High above the molten surface, they form a reflective layer that bounces radiation back into space before it can heat the planet further.

The atmosphere also moves heat from the permanently lit dayside toward the dark nightside, keeping temperatures lower than expected. Scientists still don't know exactly which gases surround TOI-561 b, but the leading candidates are carbon dioxide like Venus or sulfur dioxide from volcanic activity.

The bigger mystery is how the atmosphere survived at all. Intense radiation from the star should have blasted away any gases long ago. One explanation is that the planet started with an enormous supply of atmosphere. The other is even more remarkable: the global ocean of molten rock may act like a planet-wide volcano, constantly releasing fresh gases to replace what gets lost to space.

Professor Lisa Dang, who led the project at the University of Waterloo, said the measurements revealed how the planet's brightness and heat changed throughout its orbit. This technique showed that light was being reflected and heat redistributed around the entire world, both signs pointing to a substantial atmosphere.

Why This Inspires

This discovery challenges what scientists thought possible in extreme environments. TOI-561 b shouldn't exist as it does, yet nature found a way to protect even a world of fire with its own built-in shield. The finding opens new questions about how planets evolve and survive in hostile conditions.

Researchers now plan additional observations to identify the specific gases in the atmosphere and determine whether TOI-561 b resembles a superheated Venus or something closer to Jupiter's volcanic moon Io on an extreme scale.

Even in the harshest corners of the universe, resilience finds a way.