{"id":412768,"date":"2026-05-05T11:18:17","date_gmt":"2026-05-05T11:18:17","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/412768\/"},"modified":"2026-05-05T11:18:17","modified_gmt":"2026-05-05T11:18:17","slug":"astronomers-explore-the-surface-composition-of-a-nearby-super-earth","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/412768\/","title":{"rendered":"Astronomers explore the surface composition of a nearby super-Earth"},"content":{"rendered":"

<\/p>\n

\"High-resolution<\/p>\n

<\/a><\/p>\n

image:\u00a0<\/p>\n

This high-resolution photo of the planet Mercury probably resembles the rocky exoplanet LHS\u00a03844\u00a0b. Results from JWST observations favour an airless rocky planet with a dark, basalt-like surface, likely space-weathered by irradiation and meteorite impacts.<\/p>\n

view more\u00a0<\/a><\/p>\n

Credit: NASA\/Johns Hopkins University Applied Physics Laboratory\/Carnegie Institution of Washington (cropped)
\nhttps:\/\/science.nasa.gov\/photojournal\/mercury-globe-0n-180e\/<\/p>\n

Using MIRI (Mid Infrared Instrument) on board the James Webb Space Telescope (JWST), a team of researchers led by former MPIA (Max Planck Institute for Astronomy, Heidelberg, Germany) PhD student Sebastian Zieba (Center for Astrophysics | Harvard & Smithsonian, Cambridge, USA) and Laura Kreidberg, MPIA Director and study PI (principal investigator), analysed the surface composition of the rocky exoplanet LHS\u00a03844\u00a0b. Beyond characterizing exoplanetary atmospheres, this kind of deciphering the geological properties of planets orbiting distant stars is the next step in unveiling their nature. The results of this investigation are now published in the journal Nature Astronomy.<\/p>\n

LHS\u00a03844\u00a0b is a rocky planet 30% bigger than Earth and orbits a cool red dwarf star once within roughly 11 hours. Whirling just three stellar diameters above the host star\u2019s surface, the planet is tidally locked to its orbit. This means one rotation takes just as long as one revolution. As a result, the same hemisphere of LHS\u00a03844\u00a0b always faces its star, producing a constant dayside with an average temperature of about 1000\u00a0Kelvin (approximately 725 Degrees Celsius or 1340 Degrees Fahrenheit). The LHS\u00a03844 system is only 48.5\u00a0light-years (14.9 parsecs) away from Earth.<\/p>\n

\u201cThanks to the amazing sensitivity of JWST, we can detect light coming directly from the surface of this distant rocky planet. We see a dark, hot, barren rock, devoid of any atmosphere.\u201d \u2013 Laura Kreidberg, MPIA.<\/p>\n

With its dark surface, LHS\u00a03844\u00a0b may resemble a larger version of the Moon or the planet Mercury. This conclusion is based on analysing the infrared radiation received from the planet\u2019s hot dayside. However, when measuring this radiation, we cannot see the planet directly; instead, we register the repeating change in brightness we receive from the star and the orbiting planet combined.<\/p>\n

MIRI divided a portion of the planet\u2019s infrared emission, ranging from 5 to 12 micrometres, into smaller wavelength sections and measured the brightness per wavelength bin. This is what astronomers call a spectrum, a rainbow-like distribution of the light\u2019s components. Another data point, obtained from observations with the Spitzer Space Telescope and published a few years ago, augmented the analysis.<\/p>\n

Similar to how exoplanetary atmosphere research has benefited from climate science, this emerging field of exoplanetary geology draws on Earth-based geologic knowledge. Zieba, Kreidberg, and their collaborators ran models and accessed template libraries of rocks and minerals known from Earth, the Moon, and Mars to see what infrared signatures they would produce under the conditions on LHS\u00a03844\u00a0b. Comparing observation-based data with these computations confidently ruled out a composition comparable to Earth\u2019s crust, typically silicate-rich minerals such as granite.<\/p>\n

Although this result is not very surprising \u2013 even in the Solar System, Earth is the only planet with such a crust \u2013 it may reveal details on LHS\u00a03844\u00a0b\u2019s geological history. Earth-like silicate-rich crusts are thought to form through a prolonged refinement process that requires tectonic activity and typically relies on water as a lubricant. The rocky material repeatedly melts and solidifies as it is mixed with mantle material, leaving the lighter minerals on the surface.<\/p>\n

\u201cSince LHS\u00a03844\u00a0b lacks such a silicate crust, one may conclude that Earth-like plate tectonics does not apply to this planet, or it is ineffective,\u201d says Sebastian Zieba. \u201cThis planet likely only contains little water.\u201d<\/p>\n

Instead, the dark surface points to a composition reminiscent of terrestrial or lunar basalt, or of Earth\u2019s mantle material. However, the astronomers attempted an even more detailed characterization.<\/p>\n

A statistical analysis of how well this spectrum fits various mineral mixtures and configurations revealed that extended solid areas of basalt or magmatic rock best match the observations. They are rich in magnesium and iron and can include olivine. Crushed material, such as rocks or gravel, also fits fairly well, whereas grains or powders are inconsistent with the observations due to their brighter appearance, at least at first glance.<\/p>\n

Without a protective atmosphere, planets are subjected to space weathering, predominantly driven by hard, energetic radiation from the host star and impacts from meteorites of various sizes.<\/p>\n

\u201cIt turns out, these processes not only slowly dissolve hard rocks into regolith, a layer of fine grains or powder as found on the Moon,\u201d explains Zieba. \u201cThey also darken the layer by adding iron and carbon, making the regolith\u2019s properties more consistent with the observations.\u201d<\/p>\n

This assessment left the astronomers with two scenarios for the planet\u2019s surface that match the data equally well. One involves a surface dominated by dark, solid rock composed of basaltic or magmatic minerals. Compared to geological timescales, space weathering alters its properties quickly. Therefore, the astronomers conclude that, in this scenario, the surface should be relatively fresh, produced by recent geological activity, such as widespread volcanism.<\/p>\n

The second scenario also proposes a dark surface, comparable to the Moon or Mercury. Still, it accounts for prolonged space weathering, which leads to extended regions covered by a darkened regolith layer, a fine powder also present on the Moon, as evidenced by the iconic photos of the astronauts\u2019 footprints. This alternative relies on longer periods of geological inactivity, thereby requiring conditions opposite to the first scenario.<\/p>\n

These two alternatives differ in the degree of recent geological activity required. On Earth and other active objects in the Solar System, a typical phenomenon during such activity is outgassing. Sulphur dioxide (SO2) is a gas commonly connected to volcanism. If present on LHS\u00a03844\u00a0b in reasonable amounts, MIRI should have detected it. Still, it found nothing. Therefore, a recent period of activity seems unlikely, which leads the astronomers to favour the second scenario. If correct, LHS\u00a03844\u00a0b may truly look much like Mercury indeed.<\/p>\n

In order to test their idea, Zieba, Kreidberg, and their colleagues are already pursuing a more direct approach. They have obtained additional JWST observations, which should enable them to discern surface conditions by exploiting small differences in how solid slabs and powders emit or reflect light. The distribution of emission angles depends on surface roughness, which affects the amount of radiation received at a given viewing angle. This concept is successfully applied to characterizing asteroids in the Solar System. \u201cWe are confident the same technique will allow us to clarify the nature of LHS\u00a03844\u00a0b\u2019s crust and, in the future, other rocky exoplanets,\u201d concludes Kreidberg.<\/p>\n

\u00a0<\/p>\n

Laura Kreidberg is the only MPIA astronomer involved in this study.<\/p>\n

Other researchers were: Sebastian Zieba (Center for Astrophysics | Harvard & Smithsonian, Cambridge, USA), Brandon P. Coy (Department of the Geophysical Sciences, University of Chicago, USA), Aaron Bello-Arufe (Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA [JPL]), Kimberly Paragas (Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, USA), Xintong Lyu (Peking University, Beijing, China), Renyu Hu (The Pennsylvania State University, University Park, USA and JPL), Aishwarya Iyer (NASA Goddard Space Flight Center, Greenbelt, USA), Kay Wohlfarth (Technische Universit\u00e4t Dortmund, Germany)<\/p>\n

The JWST observations used in this study were conducted as part of GO program #1846 (PI: Laura Kreidberg, co-PI: Renyu Hu) titled \u201cA Search for Signatures of Volcanism and Geodynamics on the Hot Rocky Exoplanet LHS\u00a03844\u00a0b.\u201d<\/p>\n

The MIRI consortium comprises the ESA (European Space Agency) member states: Belgium, Denmark, France, Germany, Ireland, the Netherlands, Spain, Sweden, Switzerland, and the United Kingdom. National science organisations fund the consortium\u2019s work \u2013 in Germany, the Max Planck Society (MPG) and the German Aerospace Center (DLR). Participating German institutions include the Max Planck Institute for Astronomy in Heidelberg, the University of Cologne, and Hensoldt AG in Oberkochen, formerly Carl Zeiss Optronics.<\/p>\n

The James Webb Space Telescope is the world\u2019s leading observatory for space research. It is an international programme led by NASA and its partners ESA and CSA (Canadian Space Agency).<\/p>\n

The Spitzer Space Telescope was operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA.<\/p>\n

Method of Research<\/p>\n

Observational study<\/p>\n

Subject of Research<\/p>\n

Not applicable<\/p>\n

Article Title<\/p>\n

The dark and featureless surface of rocky exoplanet LHS 3844 b from JWST mid-infrared spectroscopy<\/p>\n

Article Publication Date<\/p>\n

4-May-2026<\/p>\n","protected":false},"excerpt":{"rendered":"image:\u00a0 This high-resolution photo of the planet Mercury probably resembles the rocky exoplanet LHS\u00a03844\u00a0b. Results from JWST observations…\n","protected":false},"author":2,"featured_media":412769,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[111,139,69,147,392],"class_list":["post-412768","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-new-zealand","tag-newzealand","tag-nz","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/412768","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=412768"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/412768\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/412769"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=412768"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=412768"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=412768"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}