4 Barnard’s Star Planets Likely Lost Atmospheres Within 2 Billion Years
Updated
Updated · Sci.News · Jul 16
4 Barnard’s Star Planets Likely Lost Atmospheres Within 2 Billion Years
3 articles · Updated · Sci.News · Jul 16
Summary
Four sub-Earth planets around Barnard’s Star appear too hostile for life, with a new analysis pointing to stripped atmospheres and interiors rich in periclase.
6 light-years from Earth, the 10-billion-year-old red dwarf has unusually high magnesium, leading researchers to infer planets that store water poorly because periclase replaces more water-friendly minerals such as olivine.
10 times closer than Mercury is to the Sun, even the outermost planet likely could not retain an atmosphere for more than 2 billion years, and all four are thought to be tidally locked.
A 9:12:16 orbital resonance among the inner three planets may still be stabilizing the compact system, which might otherwise face collisions, ejections or a plunge into the star.
2025 discoveries of these small rocky worlds could foreshadow many more finds as missions such as ESA’s Plato improve detection of sub-Earth exoplanets.