Two Super‑Puffy Planets Defy Density Limits, Weigh Less Than Cotton Candy

Astronomers have identified a pair of enormous exoplanets orbiting a star 1,110 light‑years away that are so low in density they could be described as lighter than cotton candy. The discovery, made using data from the Kepler space telescope, highlights how diverse planetary systems can be and raises new questions about how such inflated worlds form and survive.

What Makes These Planets “Puffy”?

Both planets are roughly the size of Jupiter, yet their masses are only a fraction of what would be expected for bodies of that volume. This means their average densities are lower than even the lightest known materials, such as cotton candy. The phenomenon is often referred to as “super‑puff” because the planets’ radii are inflated relative to their mass.

How Were They Detected?

The team used the transit method, observing the slight dimming of the host star as the planets passed in front of it. By measuring the depth and duration of the transits, scientists could estimate both the planets’ sizes and their orbital periods. Follow‑up observations with ground‑based telescopes helped refine the mass estimates, confirming the unusually low densities.

Implications for Planetary Science

These findings challenge existing models of planet formation, which predict that massive planets should have higher densities due to gravitational compression. The existence of such inflated worlds suggests that additional processes—such as intense stellar radiation or internal heating—may puff up a planet’s atmosphere over time. Understanding these mechanisms could provide insight into the early stages of planetary evolution and the diversity of exoplanetary systems.

What’s Next?

Future observations with the James Webb Space Telescope and upcoming ground‑based observatories will aim to characterize the atmospheres of these super‑puffy planets in greater detail. By studying their composition and temperature profiles, scientists hope to uncover the forces that keep them so inflated.

Source: CBS News

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