Webb Telescope Detects Unexpected Atmosphere on Ancient Super Earth Astronomers have discovered compelling evidence that a scorching, molten super Earth once thought to be barren may actually possess a thick, mysterious atmosphere. The findings, published in The Astrophysical Journal Letters, were made using NASA’s James Webb Space Telescope (JWST) and challenge existing assumptions about how such extreme planets retain gas. The planet, designated TOI-561 b, orbits an ancient star at a distance just one fortieth that of Mercury from the Sun, completing a full orbit in just 10.56 hours. Its surface is likely perpetually locked in daylight, with one side permanently scorched by its star’s heat. TOI-561 b has about twice Earth’s mass but differs dramatically in other aspects. Its star, slightly smaller and cooler than the Sun, combined with its extremely close orbit, creates conditions where the planet’s dayside temperature could reach nearly 4,900 degrees Fahrenheit (2,700 degrees Celsius) if it lacked an atmosphere. However, JWST observations revealed a cooler temperature of about 3,200 degrees Fahrenheit (1,800 degrees Celsius), suggesting heat is being redistributed across the planet. This discrepancy points to the presence of a thick atmosphere, which would trap and redistribute thermal energy. The planet’s low density further complicates its characterization. While not classified as a “super-puff” or “cotton candy” planet—terms for exceptionally low-density worlds—its density is lower than expected for a rocky body with an Earth-like composition. Researchers propose that TOI-561 b’s unique structure may involve a smaller iron core and a lighter mantle, possibly due to its formation in a chemically distinct environment.#james_webb_space_telescope #toi561_b #the_astrophysical_journal_letters #university_of_groningen #carnegie_institution_for_science
