James Webb Discovers An Exoplanet Shaped Like A Rugby Ball Where It Rains… Diamonds

Our vast Universe clearly has a very particular sense of aesthetics. Just when we thought we had seen it all when it came to bizarre exoplanets (more than 6,000 exoplanets confirmed in 2025), the James Webb Telescope (JWST) has just trained its mirrors on PSR J2322-2650b. A barbaric name for a world which resembles an American football (or rugby ball, they look a bit similar) lost in the void, and whose atmosphere would make any jeweler dream: diamonds would fall there in the form of rain.

James Webb has, however, seen some green and unripe ones since its launch in 2021: impossible galaxies, early black holes, ice or gas giants… it seems as if the catalog was exhausted. But for now, PSR J2322-2650b may be the strangest object he had ever been given to observe.

A planet passed through the gravitational steamroller

PSR J2322-2650b has a mass comparable to that of Jupiter, so it is 300 times heavier than Earth: a beautiful baby, therefore. If this planet has lost its roundness to display the silhouette of an oval balloon, it’s because of its toxic neighborhood. It forms with its star what astronomers call a system “ black widow ».

The star in question is a pulsar: the corpse of a dead star which rotates on itself at dizzying speed, sweeping space with jets of radiation, like an extremely fast cosmic beacon. The planet is so close that it is being put through a mill: the monstrous gravity of the pulsar stretches it like plasticinehence its rugby ball or lemon (ellipsoidal) shape.

PSR J2322-2650b receives such intense doses of radiation from its pulsar that it heats its atmosphere to the point of evaporating it into the vacuum of space. Day after day, it therefore loses material, a process of extreme erosion which, over very long time scalescould end up stripping the planet of much of its mass.. For Peter Gao, Carnegie Earth and Planets Laboratorythe surprise was total: “ I remember after receiving the data our collective reaction was: “What is this crazy?” ».

A luxury climate

In addition to its shape, the other surprise of PSR J2322-2650b is its atmosphere. By analyzing the light filtered by its atmosphere, the James Webb telescope detected a chemical signature, again very improbable, even for an exoplanet: an overwhelming domination of helium and carbon. The majority of other exoplanets are surrounded by gas mixtures that can be compared, from a distance, to the planets of our Solar System (hydrogen, methane, water, etc.). It is therefore not here that we will find any sign of life, its environment is far too hostile for that.

In this high-pressure cauldron, researchers estimate that carbon could form thick clouds of soot. Subjected to extreme conditions of temperature and pressure within the atmosphere, these particles could then crystallize. Like carbon, once a certain compression threshold is reached, it can change structure and turn into pure diamond. According to Peter Gao’s team, these crystals could form at altitude before falling back towards the planet in the form of rain.

None of our theoretical models of planetary formation allows, to date, to understand comment PSR J2322-2650b a pu se former. It is therefore the pure product of a set of astrophysical phenomena of which we have no idea and that our theories have not yet formalized. Observing such a world forces us to recognize that our models have been developed from a conception perhaps too fragmentary of stellar environmentsinsufficient for explain the existence of certain celestial objects. A thought nonetheless for Gao and his team, who must certainly be wondering how many other planets of the same kind still waiting to be discovered.