Using the James Webb Space Telescope, astronomers have found compelling evidence of a thick atmosphere surrounding an ultra-hot rocky exoplanet. The discovery challenges long-held beliefs about whether small, star-hugging planets can retain atmospheres at all. Using the James Webb Space Telescope, astronomers have found compelling evidence of a thick atmosphere surrounding an ultra-hot rocky exoplanet. The discovery challenges long-held beliefs about whether small, star-hugging planets can retain atmospheres at all.