Recent findings suggest the existence of a new class of exoplanets, challenging existing classifications. The planet, named L 98-59 d, was previously categorized as a super-Earth or sub-Neptune but has now been identified as a molten exoplanet with a significant magma ocean and volatile gases in its atmosphere.
This discovery was made using the Webb space telescope, with follow-up observations revealing high levels of sulfur dioxide among other gases. Located approximately 35 light-years from Earth, L 98-59 d is about twice the mass of our planet and orbits a cool, small star alongside four other planets.
Researchers from the University of Oxford, led by Harrison Nicholls, conducted computer simulations that traced the planet's evolution over five billion years. These simulations indicated that the planet's mantle is likely composed of molten silicate, similar to Earth's lava, and that the magma ocean facilitates chemical exchanges with its atmosphere.
The findings suggest that current classifications of small planets may be overly simplistic, prompting questions about other undiscovered planetary types in the universe.