Astronomers detected a helium-rich outflow from the super-Neptune TOI-3884b. Observed as a pre-transit headwind, this specific pattern was previously seen only on a different planet type, confirming active atmospheric escape.
The asymmetry points to magnetic interactions between the star and planet, rather than just heat. This allows scientists to directly test theories about how stellar winds shape planetary magnetic fields and drive atmospheric loss over time.
✦ A one-sided gas tail provides a direct way to test theories of planetary magnetic fields.