{"id":589439,"date":"2026-07-16T22:39:16","date_gmt":"2026-07-16T22:39:16","guid":{"rendered":"https:\/\/www.europesays.com\/ie\/589439\/"},"modified":"2026-07-16T22:39:16","modified_gmt":"2026-07-16T22:39:16","slug":"barnards-star-planetary-system-may-be-filled-with-water-poor-rocky-worlds","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/ie\/589439\/","title":{"rendered":"Barnard\u2019s Star Planetary System May Be Filled with Water-Poor Rocky Worlds"},"content":{"rendered":"

A new analysis suggests the four sub-Earth exoplanets orbiting Barnard\u2019s star \u2014 the Sun\u2019s nearest single-star neighbor \u2014 are likely packed with the deep-Earth mineral periclase, stripped of their atmospheres and far too hostile to support life.<\/strong><\/p>\n

\"An<\/a><\/p>\n

An artist\u2019s illustration of exoplanets orbiting Barnard\u2019s star. Image credit: International Gemini Observatory \/ NOIRLab \/ NSF \/ AURA \/ P. Marenfeld.<\/p>\n

Barnard\u2019s star<\/a> is a 10-billion-year-old red dwarf just 6 light-years from Earth in the constellation of Ophiuchus.<\/p>\n

Also known as Gliese 699 or GJ 699, it is the next closest star to our Sun after the Alpha Centauri triple stellar system.<\/p>\n

Discovered in 2025, the four rocky planets orbiting the star<\/a> are all smaller than Earth and Venus, but larger than Mars.<\/p>\n

By analyzing the chemical make-up of Barnard\u2019s star, University of Cambridge astronomer Xander Byrne and colleagues found that the planets are rich in a rare mineral called periclase, which on Earth is only found hundreds of km below the surface.<\/p>\n

\u201cBarnard\u2019s star has an enormous amount of the element magnesium compared to other stars, so its planets are likely to be rich in magnesium too,\u201d Dr. Byrne said.<\/p>\n

\u201cOn Earth, that magnesium goes into making minerals called olivines, which are really important for storing water within the planet.\u201d<\/p>\n

The astronomers found that the abundance of magnesium creates huge quantities of periclase, which does not store water as well.<\/p>\n

To make matters worse, they found the chances of Bernard\u2019s star planets having atmospheres to be unlikely.<\/p>\n

\u201cThese planets were always going to be hostile, because they\u2019re really close to their star,\u201d Dr. Byrne said.<\/p>\n

\u201cEven the outermost planet orbits ten times closer than Mercury orbits the Sun.\u201d<\/p>\n

\u201cWhen you\u2019re that close to your star, and have such little gravity, your atmosphere just gets blown off.\u201d<\/p>\n

The planets could have held on to their atmospheres for at most two billion years \u2014 much shorter than the system\u2019s 10-billion-year age.<\/p>\n

Being so close to the star has another consequence for the planets: the researchers found that the planets are all tidally locked.<\/p>\n

In the same way that the Moon only shows one face to the Earth, the Barnard\u2019s star planets each only show one face to their star.<\/p>\n

As a result, each planet has one hemisphere locked in eternal daylight; the other, eternal night.<\/p>\n

Planetary systems as compact as the one around Barnard\u2019s star are often unstable, with gravitational interactions between the planets sometimes leading to them colliding, falling into the star, or being ejected from the system.<\/p>\n

However, the scientists found that a phenomenon called orbital resonance might be helping to stabilize the Barnard\u2019s star system.<\/p>\n

The lengths of the \u2018years\u2019 of the inner three planets are in a 9:12:16 ratio: musically, this is equivalent to two consecutive perfect fourths.<\/p>\n

These orbital harmonies are responsible for stabilizing the orbits of the moons of Jupiter, and may be protecting the Barnard\u2019s star system from gravitational disarray.<\/p>\n

Upcoming missions, such as ESA\u2019s Plato mission, may find many more small planets like those around Barnard\u2019s star.<\/p>\n

\u201cLarger planets are much easier to detect than small ones, so we know about very few sub-Earth planets like the ones in this system,\u201d Dr. Byrne said.<\/p>\n

\u201cBut the sensitivity of these new missions will help to reduce this bias, allowing us to discover more and more planets that are small and rocky, like Earth.\u201d<\/p>\n

The team\u2019s paper<\/a> was published June 24 in the Monthly Notices of the Royal Astronomical Society.<\/p>\n

_____<\/p>\n

Xander Byrne et al. 2026. The Barnard\u2019s Star planetary system: stability, composition, and evolution of four sub-Earth exoplanets. MNRAS 550 (2): stag1207; doi: 10.1093\/mnras\/stag1207<\/p>\n","protected":false},"excerpt":{"rendered":"A new analysis suggests the four sub-Earth exoplanets orbiting Barnard\u2019s star \u2014 the Sun\u2019s nearest single-star neighbor \u2014…\n","protected":false},"author":2,"featured_media":589440,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[77],"tags":[10210,249896,249897,249898,249899,249900,18,18060,71388,19,17,522,249901,52185,51059,133,11186,249902,447],"class_list":["post-589439","post","type-post","status-publish","format-standard","has-post-thumbnail","category-science","tag-atmosphere","tag-barnards-star","tag-barnards-star-b","tag-barnards-star-c","tag-barnards-star-d","tag-barnards-star-e","tag-eire","tag-exoplanet","tag-habitability","tag-ie","tag-ireland","tag-magnesium","tag-periclase","tag-planetary-system","tag-red-dwarf","tag-science","tag-star","tag-sub-earth","tag-water"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@ie\/116932062316960926","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/589439","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/comments?post=589439"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/posts\/589439\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media\/589440"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/media?parent=589439"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/categories?post=589439"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/ie\/wp-json\/wp\/v2\/tags?post=589439"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}