NASA Telescope Detects Daily Stone Clouds on Distant Planet

NASA astronomers have discovered silicate clouds that form every day and evaporate each night on the exoplanet WASP-94A b ^[1].

This discovery provides a rare glimpse into the volatile atmospheric chemistry of "hot-Jupiter" planets, demonstrating how extreme temperatures drive rapid weather cycles. By observing these transitions, scientists can better understand the composition and climate of worlds far beyond the U.S. solar system.

WASP-94A b is located in the constellation Microscope, approximately 260 light-years from Earth ^[2]. The planet is characterized by its immense brightness, reflecting 80% of its star's light ^[2]. Because of its proximity to its host star, the planet reaches maximum temperatures of approximately 1,000 °C ^[3].

The observations were made using the James Webb Space Telescope. The data revealed that the clouds are composed of silicates, which are essentially stone [1, 3]. These stone clouds emerge during the planet's day side and vaporize as the planet rotates into night, a cycle that repeats daily [1, 3].

This atmospheric behavior is unique compared to Earth's water-based weather systems. On WASP-94A b, the heat is so intense that minerals which would be solid on Earth exist as gas or suspended droplets. The rapid formation and disappearance of these clouds suggest a highly dynamic environment where mineral precipitation occurs on a constant loop ^[3].

Astronomers continue to analyze the data to determine the exact altitude and thickness of these silicate layers. The ability to track these changes in real-time allows researchers to map the temperature gradients across the planet's surface ^[1].