Astronomers using the James Webb Space Telescope (JWST) have discovered an exoplanet unlike any observed before: PSR J2322-2650b. This world, orbiting a “black widow” pulsar – a rapidly spinning dead star – defies existing planetary formation theories with its peculiar shape and atmosphere. The discovery raises fundamental questions about how planets can form under extreme conditions.
A Planet Shaped by Extreme Forces
PSR J2322-2650b is approximately the size of Jupiter, but far from spherical. Intense tidal forces from the nearby pulsar have stretched it into an ellipsoid shape, resembling a lemon or football. This distortion is driven by the pulsar’s immense gravity, which relentlessly tugs at the planet.
The planet orbits its star at just 1 million miles – incredibly close, completing one orbit every 8 hours. This proximity results in extreme temperature differences between the dayside (3,700°F) and the nightside (1,200°F). The discovery was made possible because pulsars emit minimal infrared light, which allowed the JWST to observe the planet’s atmosphere without interference.
An Unprecedented Atmospheric Composition
The most astonishing aspect of PSR J2322-2650b is its atmosphere. Instead of familiar molecules like water, methane, or carbon dioxide, it’s dominated by helium, carbon, and likely clouds of carbon soot. Under such high temperatures, this carbon condenses into diamonds that may rain down onto the planet’s surface.
The atmosphere contains high concentrations of molecular carbon (C₂ and C₃), something never previously detected on an exoplanet. This composition suggests that the planet formed in a way that defies current understanding. The extreme lack of oxygen and nitrogen is unusual and unknown.
Why This Matters: Challenging Planetary Formation Theories
The existence of PSR J2322-2650b challenges established theories of planetary formation. The planet’s unique composition suggests it did not form conventionally, nor was it likely created by stripping material from a star. Existing models cannot explain how such a carbon-rich environment could emerge naturally.
One hypothesis suggests the planet’s interior may have crystallized carbon, separating it from oxygen and nitrogen. However, the mechanism that keeps these lighter elements away remains a mystery. As one researcher put it: “It seems to rule out every known formation mechanism.”
This discovery underscores the vast diversity of planetary systems beyond our own and highlights the limitations of current models. PSR J2322-2650b provides a new puzzle for astrophysicists to unravel, pushing the boundaries of our knowledge about how planets can exist in the universe.
“This is a new type of planet atmosphere that nobody has ever seen before.” – Michael Zhang, University of Chicago.
The unusual conditions surrounding this exoplanet will continue to be investigated as researchers seek to better understand the extremes of planetary systems.
