Most reflective planet: Scorching hot world where metal clouds rain titanium discovered

Astronomers have announced the discovery of a highly reflective exoplanet located over 260 light years away from Earth. This scorching hot world, where titanium rains down in the form of metal clouds, reflects an astonishing 80 percent of the light it receives from its host star. The observations were made using Europe’s Cheops space telescope, designed for studying exoplanets.

This exoplanet is now recognized as the most reflective planet ever observed outside our solar system, with a comparable brightness to Venus, the brightest object in the night sky after the Moon. Given the name LTT9779b, the planet is Neptune-sized, significantly larger than Earth, and was first discovered in 2020. It completes an orbit around its star in just 19 hours.

One intriguing aspect of LTT9779b is its close proximity to its host star, resulting in extreme heat. The side of the planet facing the star reaches temperatures of around 2000 degrees Celsius, typically too hot for cloud formation. However, the presence of clouds on the planet puzzled researchers.

Vivien Parmentier, a researcher at France’s Cote d’Azur Observatory and co-author of the study, likened the cloud formation to condensation forming in a bathroom after a hot shower. In this analogy, an oversaturated atmosphere on LTT9779b led to the formation of metallic clouds, similar to how hot water vapor in a bathroom creates condensation on surfaces.

The exoplanet, which is approximately five times the size of Earth, also stands out in other ways. It resides in a region known as the “Neptune desert,” where planets of its size are not expected to exist. Parmentier stated that this planet defies expectations, as similar planets are anticipated to have their atmospheres stripped away by their star, leaving behind only bare rock.

The presence of the reflective metallic clouds on LTT9779b acts as a shield, preventing the atmosphere from being blown away. The clouds behave like mirrors, reflecting light and offering a protective barrier, similar to the shields depicted in Star Trek movies, as described by Cheops project scientist Maximilian Guenther.

The discovery of this highly reflective exoplanet offers valuable insights into the diverse and unusual nature of exoplanetary systems and expands our understanding of planetary formation and composition beyond our own solar system.