2026-05-04 マックス・プランク研究所
Infrared spectrum of LHS 3844 b’s hot dayside derived from the brightness contrast to its host star in ppm (parts per million = 0.0001%) at different wavelengths. The observational data obtained from the James Webb and Spitzer Space Telescopes are consistent with mantle or lava rock, whereas they rule out an Earth-like crust.
＜関連情報＞
- https://www.mpg.de/26189037/astronomers-explore-the-surface-composition-of-a-nearby-super-earth
- https://www.mpg.de/26445820/zieba_2026_lhs3844b_initialsubmission.pdf
- https://www.nature.com/articles/s41550-026-02860-3
JWSTの中赤外線分光観測による、岩石質の系外惑星LHS 3844 bの暗く特徴のない表面 The dark and featureless surface of rocky exoplanet LHS 3844 b from JWST mid-infrared spectroscopy
Sebastian Zieba,Laura Kreidberg,Brandon P. Coy,Aaron Bello-Arufe,Kimberly Paragas,Xintong Lyu,Renyu Hu,Aishwarya Iyer,Edwin S. Kite,Daniel D. B. Koll,Kay Wohlfarth,Emerson Whittaker,Heather Knutson,Robin Wordsworth,Caroline Morley & Laura Schaefer
Nature Astronomy Published:04 May 2026
DOI:https://doi.org/10.1038/s41550-026-02860-3
Abstract
The James Webb Space Telescope (JWST) has opened a new era in the study of rocky exoplanets, enabling direct characterization of their surfaces with mid-infrared spectroscopy. Different types of rock have distinct spectral features that are diagnostic of the chemical composition and other physical properties like surface texture. Measurements of these features can provide valuable clues about a planet’s geologic history and interior processes. Here we report a JWST 5–12-μm thermal emission spectrum for the rocky exoplanet LHS 3844 b. It is best matched by a dark, low-silica surface, such as basalt or other olivine-rich materials. The spectrum rules out surfaces covered by fresh, small-sized grains (powders); however, space weathering can darken the powders and make them more consistent with the data. The data also disfavour trace concentrations of CO2 or SO2 gas (with 5σ and 3σ upper limits of 100 mbar and 10 μbar, respectively). Taken together, these results are well fit by an old, space-weathered surface with no evidence of accumulated volcanic gases.
