Exoplanet TOI-561 b may possess a reflective, mineral-rich atmosphere

Astronomers using the James Webb Space Telescope have discovered evidence that the lava exoplanet TOI-561 b may possess a thick, reflective atmosphere. Despite being a rocky ‘super-Earth’ located extremely close to its host star—with an orbital period of only 0.44 days—the planet reflects approximately 75% of the stellar light it receives.

Researchers suggest this reflection is caused by a natural “sunscreen” composed of silicate mineral clouds, such as silicon dioxide and magnesium silicate. This atmospheric layer prevents the planet from reaching the extreme temperatures typically expected for a heavily irradiated rocky world.

The discovery challenges existing planetary theories, as such intense radiation usually strips planets of their atmospheres over time. Scientists are currently investigating whether the planet began with an unusually large supply of gases or if its surface of molten rock acts as a continuous source of volcanic outgassing to replenish the atmosphere.