Exoplanets, -moons, -comets

NASA’s Pandora SmallSat Mission: Simulated Modeling and Retrieval of Near-Infrared Exoplanet Transmission Spectra

By Keith Cowing

Status Report

astro-ph.EP

March 9, 2026

Filed under astro-ph.EP, astronomy, atmosphere, exoplanet, HAT-P-18 b, HD189733 b, HD209458 b, hot jupiter, JWST, K2-18 b, NASA, Pandora Mission, smallsat, Spectroscopy, sub-Neptune, telescope, WASP-80~b

NASA’s Pandora SmallSat Mission: Simulated Modeling and Retrieval of Near-Infrared Exoplanet Transmission Spectra — The absorption cross sections of common absorbers in exoplanet atmospheres considered in this work, shown at a pressure and temperature of 0.1 mbar and 1000 K. The wavelength coverage of Pandora’s NIR detector (NIRDA), JWST’s NIRCam F322W2 and F444W filters, and HST’s WFC3 instrument (for the G141 grism) are shown. Pandora/NIRDA covers absorption bands of H2O, CH4, NH3 and the wing of the K doublet, making it most sensitive to these absorbers. — NASA

Pandora is a SmallSat mission dedicated to understanding exoplanets and their host stars by disentangling the impact of stellar heterogeneity on exoplanet transmission spectra.

Selected as a NASA Astrophysics Pioneers mission in 2021, Pandora will provide simultaneous long-term visible photometric monitoring (0.4–0.7 μm) and low-resolution near-infrared (NIR) spectroscopy (0.9–1.6 μm) of transiting systems for the purposes of monitoring host star variability and characterizing exoplanetary atmospheres.

Pandora’s year-long prime mission from 2026 to 2027 coincides with the middle of a decade defined by targeted efforts for atmospheric characterization of exoplanets, offering a key opportunity to leverage this new resource to maximize science with JWST and other observatories. Here we investigate Pandora’s anticipated performance for the general exoplanet population accessible to transit spectroscopy, from hot Jupiters to temperate sub-Neptunes.

By modeling the atmospheres of five test cases broadly consistent with the bulk properties of HD209458 b, HD189733 b, WASP-80~b, HAT-P-18 b, and K2-18 b, we find that Pandora may provide abundance constraints as precise as ∼1.0,dex for main atmospheric absorbers such as H2O and CH4. Then, we explore the synergies between Pandora and JWST. Our results suggest that targets with JWST data in the near-infrared can benefit from the addition of Pandora observations and result in more reliable abundance estimates than with JWST data alone.

Moreover, Pandora can serve the community by providing precursory observations of targets of interest for JWST atmospheric characterization. We conclude by outlining strategies for the use of Pandora as a standalone observatory and in synergy with JWST.

Yoav Rotman, Peter McGill, Luis Welbanks, Benjamin V. Rackham, Aishwarya Iyer, Daniel Apai, Michael R. Line, Elisa V. Quintana, Jessie L. Dotson, Knicole D. Colon, Thomas Barclay, Christina Hedges, Jason F. Rowe, Emily A. Gilbert, Brett M. Morris, Jessie L. Christiansen, Trevor O. Foote, Aylin Garcia Soto, Thomas P. Greene, Kelsey Hoffman, Benjamin J. Hord, Aurora Y. Kesseli, Veselin B. Kostov, Megan Weiner Mansfield, Lindsey S. Wiser

Comments: Accepted for publication in AJ; 22 pages, 10 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2603.04488 [astro-ph.EP] (or arXiv:2603.04488v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2603.04488
Focus to learn more
Submission history
From: Yoav Rotman
[v1] Wed, 4 Mar 2026 19:00:01 UTC (5,147 KB)
https://arxiv.org/abs/2603.04488

Astrobiology

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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