A Bizarre Discovery From the James Webb Space Telescope
In a striking example of how strange our universe can be, astronomers using NASA’s James Webb Space Telescope have identified a planet with an extraordinary shape—a lemon-like world that orbits a city-sized star. The discovery, centered on the exoplanet PSR J2322-2650b, pushes the boundaries of what researchers thought planets could look like and survive around extreme stellar hosts. What makes this world so unusual is not just its size or orbit, but how its gravity from a compact, dense star sculpts it into a curved, lemon-ish form.
The Host: A City-Sized Pulsar Driving Extreme Conditions
The planet orbits a pulsar, a dead star that packs more mass than the Sun into a sphere only a few tens of kilometers across. This makes the pulsar incredibly dense and incredibly inhospitable. The intense radiation and powerful tidal forces exerted by the pulsar are believed to continuously distort the planet’s shape, much like the Moon subtly stretches the Earth, but on a far more extreme scale. The result is a world that would look elongated and curved if observed up close, a stark contrast to the near-spherical planets most people imagine when they picture exoplanets.
Why a Lemon Shape? Tidal Forces at Play
Planetary shapes are not fixed; they respond to their gravitational environment. In the case of PSR J2322-2650b, the proximity to a compact, energy-emitting star means intense tidal interactions. Over time, these forces can pull the planet into an elongated, pear- or lemon-like silhouette as it tries to maintain equilibrium against the star’s gravity. This deformation is a clue to the planet’s orbit, mass, and internal structure, offering a rare window into planetary physics under extreme irradiation and gravity.
Size, Mass, and What It Tells Us About Planetary Formation
Initial measurements show that PSR J2322-2650b is Jupiter-sized, but its mass, density, and exact composition remain active areas of study. For a planet orbiting a pulsar, survival and formation theories are continually tested. This world likely formed around its parent star before the star’s explosive past left behind a pulsar, or it could have migrated into this perilous neighborhood after the star settled into its collapsed state. Each scenario carries different implications for how planets endure catastrophic stellar events and how resilient they can be in the face of extreme radiation.
What This Means for Exoplanet Science
Discoveries like this lemon-shaped world underscore the diversity of planetary systems in our galaxy. They reveal that planets can endure, adapt, and even assume unusual shapes under conditions that would be fatal for life as we know it. For scientists, the key takeaway is that planetary interiors, atmospheres, and orbital dynamics around compact, high-energy stars deserve renewed attention. JWST’s ability to detect subtle signals in such extreme environments opens the door to uncovering more oddball worlds and refining models of planet formation, migration, and survival in the most challenging corners of the universe.
The Road Ahead: What Researchers Will Look For Next
Future observations aim to pin down the planet’s exact mass, composition, and atmospheric properties. Will the lemon-like silhouette persist across years of observation, or is it tied to a particular orbital phase? By comparing this system to other pulsar planets and extreme exoplanets, scientists hope to build a more complete picture of how such worlds form, evolve, and survive around the most extreme hosts the cosmos can offer.
As telescopes like JWST continue to push the boundaries, our catalog of oddball worlds will grow, and with it our understanding of the astonishing variety of planets that exist beyond our solar system.
