![Model SED calculations for Ceres (left), Eros (middle), and Hektor (right). For each target, the top panel (a) shows the predicted flux density at each epoch, while the bottom panel (b) shows the corresponding flux ratio between reflected and thermal radiation. The color coding represents heliocentric distance. The vertical dashed lines indicate the wavelength where the reflected and thermal flux contributions are equal. Alt text: Modeled spectral energy distributions of Ceres, Eros, and Hektor showing reflected and thermal emission contributions. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Spectroscopic.png?fit=1200%2C680&ssl=1)
[astro-ph.EP]. The small Solar System bodies (SSSBs) preserve records of the formation and evolution of the Solar System. In particular, the near-infrared wavelength region around 3 μm provides crucial insights into the origin and transport of hydrated materials and organics, although it is difficult to observe from the ground because of strong telluric absorption.
We assess the observability of SSSBs as complementary science to the ESA Ariel space mission, operating in the visible to mid-infrared wavelength range (0.5–7.8 μm). Using the NASA JPL Horizons ephemeris system, we evaluate the visibility of known SSSBs from 2032 to 2035.
Our analysis shows that Ariel can spectroscopically characterize up to 402 unique SSSBs under a conservative limiting visual magnitude of V=13.6. If observations can be extended to somewhat fainter targets (V=16), the number of observable SSSBs could increase to 2144. Assuming operational scenarios in which one SSSB is observed every 3, 7, or 30 days over a four-year mission, the total numbers of observable targets would be 357, 209, and 49, respectively.
We further model the spectral energy distributions of candidate targets to evaluate their observational performance. We demonstrate that Ariel can resolve critical absorption features, such as those at 2.7 μm and 3.4 μm, with a higher spectral resolution than the previous infrared survey with AKARI. Observations of SSSBs with Ariel can provide insights into the distribution and evolution of life-forming materials in the Solar System and constitute a scientifically compelling component of Ariel’s complementary science program.
Jin Beniyama, Eri Tatsumi, Sunao Hasegawa, Keigo Enya, Matt Griffin, Andreas Papageorgiou, Lorenzo V. Mugnai, Csaba Kiss, Moe Matsuoka, Takafumi Ootsubo, Subhajit Sarkar
Comments: 16 pages, 16 figures, 2 tables. Accepted for publication in RAS Techniques and Instruments (RASTI). Any comments are welcome
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2610.35825 [astro-ph.EP] (or arXiv:2610.35825v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2610.35825
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Submission history
From: Jin Beniyama
[v1] Mon, 26 Oct 2026 17:48:19 UTC (1,977 KB)
https://arxiv.org/abs/2610.35825
Astrobiology,
