Featured Image: Clinging to an Atmosphere

Could TOI-700 d, an Earth-sized planet in the habitable zone of an early-type M-dwarf star, have held on to its atmosphere over long timescales? This question is crucial to understanding whether this recent discovery from the Transiting Exoplanet Survey Satellite (TESS) is likely to have a habitable surface. In a recent study led by Chuanfei Dong (Princeton University), a team of scientists conducted a series of state-of-the-art simulations to model the atmospheric escape from TOI-700 d as the planet is bombarded by its host’s stellar wind. The plots above show the O+ ion density and magnetic field lines in various cases from the authors’ simulations (see the original image for scales and additional detail). Though TOI-700 d’s atmospheric ion escape rates could be a few orders of magnitude higher than the rates typical of the terrestrial planets in our own solar system, the authors show that TOI-700 d could still retain a substantial atmosphere for more than a billion years — so it may well be worth exploring this planet further in the future! For more information, check out the full article below.


“Atmospheric Escape From TOI-700 d: Venus versus Earth Analogs,” Chuanfei Dong et al 2020 ApJL 896 L24. doi:10.3847/2041-8213/ab982f