An Update on the Potential Habitability of TRAPPIST-1. No Aliens yet, but We’ve Learned a lot.

This illustration shows what the TRAPPIST-1 system might look like from a vantage point near planet TRAPPIST-1f (at right).

One year ago, I wrote an article about the remarkable discovery of the TRAPPIST-1 planetary system, a system of seven temperate terrestrial planets orbiting an ultra-cool red dwarf star. This was an enormous astronomical discovery because these low-mass stars are the most numerous ones in our galaxy, and the discovery of potentially habitable planets around one of them led many people to speculate about the existence of life there and elsewhere in our galaxy around similar stars.

This announcement also inspired a lot of additional studies by astronomers worldwide, who have used additional instruments and run complex models to better understand this planetary system and its potential for hosting life.

One year later, it seems to me that the time is right to give you an update on what we’ve learned about this planetary system, which is located only 41 light-years from Earth.

Squish! 💦

This isn’t a full blog post. Just something I saw while looking around for other things on Mars. And for once it’s (probably) not related to the wind. But it’s cool enough to share. I saw something that went “squish” 💦 : HiRISE ESP_035789_2175, NASA/JPL/Univ. of Arizona This is a ~1.2 km (0.75 mi) wide

Flow. Lots of flow.

Over the years, many things have flowed across the surface of Mars: lava, ice, water, and wind. Two things have flowed in this image (the view is 0.75×0.6 km or 0.47×0.37 mi): Image credit: HiRISE ESP_026541_1840, NASA/JPL/Univ. of Arizona If you know my blog at all, then you might recognize the big structures as yardangs.

Wind-exposed layers

On Earth, layers comprising the geological record of an area are most often exposed by fluvial erosion, as a river cuts through rock (a typical example is the Grand Canyon). On Mars, fluvial channels are not so common (especially in the past few billion years). But the wind has relentlessly worked away at the surface,

Athena Coustenis, Professional Status

Dr HDR Athena Coustenis Observatoire de Meudon 5, place Jules Janssen 92195 Meudon Cedex France PROFESSIONAL STATUS Athena Coustenis is Director of Research 1st class with the National Centre for Scientific Research (CNRS) of France, working at Paris Observatory in Meudon. Affiliation: Paris Observatory, PSL, CNRS, Sorbonne Université, U. Paris-Diderot Her specialty is Planetology (exploration