Astronomers have uncovered one of the most extreme planets ever found a scorching, rocky world that circles its star in just a few hours. The new exoplanet, named TOI-2431 b, is breaking records and giving scientists valuable insight into how planets form and evolve under extreme conditions.
A Super-Earth with an Extreme Orbit
TOI-2431 b is classified as a super-Earth, a type of rocky planet larger than our own but smaller than gas giants like Neptune. This planet is about 1.5 times the size of Earth, but what makes it stand out is its incredibly fast orbit.
The planet completes a full trip around its star in just 5.4 hours. To put that into perspective, Earth takes 365 days to orbit the Sun, while TOI-2431 b races around its host star more than 1,600 times during a single Earth year.
Located around 117 light-years away, this distant world orbits dangerously close to its star—only 0.0063 astronomical units (AU) away. That’s about 933,000 kilometers (580,000 miles), closer than the distance between the Earth and our Moon.
A World of Fire and Metal
Because of its proximity to its star, TOI-2431 b has surface conditions unlike anything on Earth. Its temperature is estimated at around 2,000 Kelvin (1,727°C or 3,140°F). At such extremes, rock and metal would not remain solid they would melt. Scientists believe the planet’s surface could be a boiling ocean of lava mixed with molten iron.
Even more surprising is its density. With a mass over six times that of Earth and a density of 9.4 grams per cubic centimeter, TOI-2431 b is heavier and more compact than most known rocky planets. This suggests it is rich in metals, possibly with a large iron core making up much of its structure.
Shaped Like an Egg
Planets that orbit so close to their stars face intense tidal forces, much like how the Moon’s gravity shapes tides on Earth. But in the case of TOI-2431 b, these gravitational forces are so strong that they distort the planet’s shape. Instead of being perfectly round, the planet is stretched out into an egg-like form.
A Planet on Borrowed Time
TOI-2431 b’s days as a planet are numbered. Because it is so close to its star, gravitational interactions are slowly pulling it inward. Astronomers estimate that in about 31 million years a blink of an eye in cosmic terms the planet will spiral into its star and be destroyed.
This makes TOI-2431 b not just fascinating but also a rare glimpse into planetary death. Studying it allows scientists to understand how extreme gravitational forces and heat reshape planets over time.
How It Was Discovered
The discovery was made using NASA’s Transiting Exoplanet Survey Satellite (TESS), which searches for planets by detecting tiny dips in starlight when a planet crosses in front of its star. Follow-up observations were carried out using ground-based telescopes, confirming its size, mass, and unusual orbit.
The research highlights the importance of ongoing surveys like TESS, which continue to find exotic planets that challenge our understanding of planetary systems.
Why TOI-2431 b Matters
While TOI-2431 b could never support life as we know it, its discovery is a breakthrough for astronomy. It pushes the limits of what we know about how planets survive or fail to survive close to their stars. By studying planets like this, scientists can test theories of planetary structure, star-planet interactions, and orbital evolution.
Extreme planets like TOI-2431 b remind us of the incredible diversity of worlds in the universe. From frozen gas giants to fiery molten rocks, each discovery helps paint a fuller picture of how unique and fragile Earth really is.
Research Reference
📄 Kaya Han Taş et al. (2025). “An Earth-Sized Planet in a 5.4h Orbit Around a Nearby K dwarf.” arXiv.