Anatomy of Empirical Transit Spectra of Mars Based on TGO/NOMAD
| dc.contributor.author | Aoki, S. | |
| dc.contributor.author | Fujii, Y. | |
| dc.contributor.author | Sagawa, H. | |
| dc.contributor.author | Villanueva, G.L. | |
| dc.contributor.author | Thomas, I. | |
| dc.contributor.author | Ristic, B. | |
| dc.contributor.author | Daerden, F. | |
| dc.contributor.author | López-Valverde, M.A. | |
| dc.contributor.author | Patel, M.R. | |
| dc.contributor.author | Mason, J. | |
| dc.contributor.author | Willame, Y. | |
| dc.contributor.author | Bellucci, G. | |
| dc.contributor.author | Vandaele, A.C. | |
| dc.date | 2026 | |
| dc.date.accessioned | 2026-03-24T09:59:13Z | |
| dc.date.available | 2026-03-24T09:59:13Z | |
| dc.identifier.uri | https://orfeo.belnet.be/handle/internal/14640 | |
| dc.description | Transit spectroscopy is a powerful tool for probing atmospheric structures of exoplanets. Accurately accounting for the effects of aerosols is key to reconstructing atmospheric properties from transit spectra, yet this remains a significant challenge. To advance this effort, it is invaluable to examine the spectral features of well-characterized planetary atmospheres. Here, we synthesize empirical transit spectra of Mars across different seasons based on data from the NOMAD’s Solar Occultation channel on board ExoMars/TGO, which operates at wavelengths of 0.2–0.65 and 2–4 μm. In the generated empirical transit spectra, the atmosphere below 25 km is found to be largely opaque due to the presence of micron-sized dust and H2O ice clouds, both of which substantially weaken spectral features. The spectra exhibit CO2 absorption features at 2.7–2.8 μm and signatures of submicron-sized mesospheric H2O ice clouds around 3.1 μm, accompanied by a continuum slope. The amplitudes of these spectral features are found to vary with the Martian seasons, where the dust storms weaken the CO2 signatures and strengthen the H2O ice features, which serve as potential indicators of a dusty planet like Mars. If TRAPPIST-1f possessed a Mars-like atmospheric structure, both CO2 and H2O ice features would be detectable at a noise level of 3 ppm, a level likely beyond current observational capabilities. Nevertheless, the 3.1 μm feature produced by submicron-sized mesospheric H2O ice clouds offers a novel avenue for characterizing the atmospheres of habitable-zone exoplanets. | |
| dc.language | eng | |
| dc.title | Anatomy of Empirical Transit Spectra of Mars Based on TGO/NOMAD | |
| dc.type | article | |
| dc.subject.frascati | Physical sciences | |
| dc.audience | Scientific | |
| dc.subject.free | Exoplanet atmospheres | |
| dc.subject.free | Extrasolar rocky planets | |
| dc.subject.free | Habitable planets | |
| dc.subject.free | Interdisciplinary astronomy | |
| dc.subject.free | Exoplanet atmospheric dynamics | |
| dc.source.title | The Astronomical Journal | |
| dc.source.volume | 171 | |
| dc.source.issue | 3 | |
| dc.source.page | A166 | |
| Orfeo.peerreviewed | Yes | |
| dc.identifier.doi | 10.3847/1538-3881/ae3da7 |