Teegarden’s Star b Keeps Atmosphere Mystery as 1.16-Earth-Mass Planet Never Transits
Updated
Updated · spacedaily.com · Jun 12
Teegarden’s Star b Keeps Atmosphere Mystery as 1.16-Earth-Mass Planet Never Transits
1 articles · Updated · spacedaily.com · Jun 12
Summary
12.5 light-years away, Teegarden’s Star b remains impossible to test for an atmosphere with current transit spectroscopy, leaving astronomers unable to tell whether the habitable-zone world is potentially livable or just bare rock.
No transit is the key obstacle: the planet never crosses its dim red dwarf from Earth’s line of sight, so telescopes cannot read atmospheric gases from starlight filtering through any air.
CARMENES data found the planet in 2019 through radial velocity, giving only a minimum mass of about 1.16 Earth masses; its radius is still unknown, and its Earth Similarity Index has been revised down to about 0.90 from roughly 0.95.
Climate estimates are also finely balanced—one 2025 model kept the planet below a runaway-greenhouse threshold, while a slightly higher irradiation estimate pushed it beyond it.
Next-generation instruments, including the Extremely Large Telescope’s planned Planetary Camera and Spectrograph and the proposed LIFE mission, are seen as the best chance to directly probe the planet’s reflected light or heat.
Why must we wait until 2030 to learn if one of our most Earth-like neighbors has an atmosphere?
Could violent stellar flares, once thought deadly, actually be the key to finding life on Teegarden's Star b?
Are we blind to countless 'Earths' because our best methods overlook planets that don't pass in front of their stars?
Teegarden's Star b Habitability in 2025: Climate Model Insights, Observational Barriers, and the Race for Direct Atmospheric Detection
Overview
Teegarden's Star b is an intriguing exoplanet that has captured scientists' attention because of its potential to harbor life. However, its true habitability remains a mystery due to uncertainties about its atmospheric conditions. Recent climate modeling efforts in late 2025 are crucial for solving this puzzle. A study by Ryan Boukrouche, Rodrigo Caballero, and Neil Lewis highlights that even small changes in the amount of stellar energy Teegarden's Star b receives can dramatically affect its chances for life. This research shows that habitability assessments are highly sensitive to basic assumptions about the planet's environment.