NASA Discovers Lemon-Shaped Exoplanet with Diamond Atmosphere

The James Webb Space Telescope has unveiled a bizarre new world that defies planetary formation theories.

Apr. 10, 2026 at 7:35am

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A bold, abstract painting in earthy tones depicting sweeping geometric arcs, concentric circles, and precise botanical spirals, representing the complex scientific forces and concepts behind the discovery of the bizarre lemon-shaped exoplanet with a diamond atmosphere.An artist's interpretation of the lemon-shaped exoplanet with a diamond-rich atmosphere, a celestial oddity that is rewriting the rules of planetary formation.Chicago Today

NASA's James Webb Space Telescope has discovered an exoplanet unlike any seen before - a lemon-shaped world with a possible diamond core and an atmosphere dominated by helium and carbon. Officially dubbed PSR J2322-2650b, this celestial body orbits a rapidly spinning neutron star, adding to its unique characteristics.

Why it matters

This discovery challenges our understanding of how planets form and the types of atmospheres they can possess. The presence of molecular carbon instead of typical compounds like water and methane suggests extreme conditions at the planet's core, potentially leading to diamond formation. Studying this 'black widow' system provides new insights into the evolution of planets and stars.

The details

The lead researcher, Michael Zhang from the University of Chicago, described the host star as having 'the mass of the Sun, but the size of a city.' The team was surprised to find molecular carbon (C3 and C2) instead of the usual water, methane, and carbon dioxide expected on an exoplanet. The intense pressure at the planet's core could be squeezing carbon into diamonds. At just 7.8 hours, PSR J2322-2650b has an incredibly short orbit around its pulsar star, with immense gravitational forces stretching the Jupiter-mass planet into a lemon shape.

  • The discovery was made in April 2026 using data from the James Webb Space Telescope.
  • The planet was officially designated as PSR J2322-2650b.

The players

Michael Zhang

A researcher from the University of Chicago who led the study of this exoplanet.

Peter Gao

A researcher from the Carnegie Earth and Planets Laboratory in Washington, D.C. who was part of the team studying this exoplanet.

Maya Beleznay

A researcher from Stanford University who worked on modeling the planet's shape.

Roger Romani

An expert in black widow systems who proposed theories about the planet's composition.

James Webb Space Telescope

The powerful infrared space observatory that made this discovery possible.

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What they’re saying

“This is a new type of planet atmosphere that nobody has ever seen before.”

— Michael Zhang, Researcher, University of Chicago

“What the heck is this?”

— Peter Gao, Researcher, Carnegie Earth and Planets Laboratory

“The Webb telescope provides a pristine spectrum of the planet, allowing for detailed study.”

— Maya Beleznay, Researcher, Stanford University

What’s next

Scientists will continue studying this unique exoplanet system to better understand how it formed and the extreme conditions that led to its diamond-rich atmosphere.

The takeaway

This discovery of a lemon-shaped exoplanet with a diamond-rich atmosphere challenges our fundamental understanding of planetary formation and composition, opening up new avenues of research into the diversity of worlds that exist in our universe.