Elisabetta Dotto

Introduction: Near-Earth Asteroids (NEAs) are asteroids with perihelion distances smaller than 1.3 AU. They represent a key population for the study of small bodies, Solar System evolution, and the possible delivery of water and organic molecules to the early Earth (Kokhirova et al. 2023)]. A subset of NEAs, the Potentially Hazardous Asteroids (PHAs), follows orbits that can approach the Earth and includes objects large enough to produce significant damage in the event of an impact. At present, about 2500 PHAs are known, including objects such as Didymos and Apophis. For these reasons, the physical characterization of NEAs, and in particular PHAs, is an important task for both Solar System science and planetary defence.The NEOPOPS project: Space missions provide detailed information on selected targets, but ground-based observations remain the main tool for the rapid physical characterization of newly discovered NEAs. As of May 2026, more than 41,000 NEAs are known, with an average discovery rate of about 3000 new objects per year. The NEO Physical Observations and Properties Simulation project (NEOPOPS) is funded by the Horizon Europe Programme, implemented by ESA and led by INAF–OAR. The project started in February 2025 and will continue until August 2028. Its goal is to improve the physical characterization rate of NEAs through complementary techniques, including photometry, spectroscopy, and polarimetry, with particular attention to rapid response observations of newly discovered objects and possible impactors.Observations: In this work, we present the first results from the first two years of the spectroscopic survey of NEAs carried out at the Asiago Observatory within Work Package 4, dedicated to spectroscopy, and Work Package 6, dedicated to rapid response observations. The observations were obtained with the 1.22 m Galileo Telescope equipped with the Boller & Chivens spectrograph, and with the 1.82 m Copernico Telescope equipped with the AFOSC spectrograph. These facilities allow low-resolution visible spectroscopy in the approximate range 0.45–1.0 μm, depending on the telescope and instrumental setup. Since the beginning of the project, 75 NEAs have been observed, including recently discovered objects, PHAs, and targets with available light-curve information.Analysis and results: The spectral analysis includes taxonomic classification based on the DeMeo et al. (2009) system, comparison with laboratory meteorite spectra (DeMeo et al. 2022), and the study of spectral slopes and absorption features. The observed sample is dominated by S-complex objects, followed by X- and C-complex asteroids. For each object, the taxonomic classification is also used to estimate the size when no direct measurement is available, assuming a representative albedo for the assigned taxonomic class. We also investigate the distribution of the observed NEAs as a function of absolute magnitude, estimated size, and orbital parameters, including perihelion distance, aphelion distance, eccentricity, inclination, and semi-major axis. This allows us to compare the spectroscopic properties of the sample with its dynamical distribution and to distinguish between NEAs and PHAs.A preliminary analysis of the phase reddening effect was also performed by studying the spectral slope as a function of phase angle in two wavelength intervals, 6000–7000 Å and 5500–9000 Å. This analysis allows us to search for possible trends between surface spectral properties and observing geometry. Several objects were observed on different nights or over a significant fraction of their rotation, allowing us to test possible spectral variability. Among them, the binary asteroid 1999 HF1 was observed over two full rotations. We also obtained twelve spectra of the PHA 2025 FA22, classified as an X-type object, which show a largely homogeneous surface over about 2.3 hours of rotational coverage.Conclusions: These first results show the role of regular spectroscopic monitoring from Asiago within the NEOPOPS project. The survey provides taxonomic and compositional information for a growing sample of NEAs, supports the rapid characterization of newly discovered objects, and allows the study of spectral variability in selected targets. The continuation of the survey will increase the statistical value of the sample and improve our knowledge of the physical properties of NEAs and PHAs.Acknowledgments: The NEOPOPS observations contract is funded by the Horizon Europe Programme of the European Union and implemented by ESA, agreement No. 4000147191/25/D/MRP.References [1] Kokhirova et al. (2023), Solar System Research, 57, 487–495.[2] DeMeo et al. (2009), Icarus, 202, 160–180.[3] DeMeo et al. (2022), Icarus, 380, 114971.

Near-Earth Objects (NEOs) provide key insights for understanding the primordial structure of planetesimals and the compositional gradient of the solar nebula. They carry information about the processes that shaped the early Solar System as a function of heliocentric distance. Furthermore, NEOs may have been instrumental in delivering water and organic-rich material to Earth, potentially contributing to the emergence of life [1].These objects can even pose a threat to our civilization. Terrestrial impact craters attest to the catastrophic effects of past asteroid collisions with our planet (e.g. the K-Pg event which occurred approximately 65 million years ago, attributed to the impact of an asteroid of about 10 km in size). Such events can produce changes in biodiversity, such as species extinction (or mass extinction) and drastic climate changes. More recently, the Chelyabinsk meteor event in February 2013 highlighted that even relatively small objects (less than 100m) can cause significant harm to human safety and infrastructure [2]. The blast created by this 20-m meteor's air burst produced extensive ground damage, and almost 1500 people sought medical attention because of the event. The overall majority of the injuries were caused by the secondary blast effects of glass which shattered and fell inward.Accurate knowledge of a target's physical properties is essential for effective mitigation measures in any potential impact scenario, as this information is crucial for planning and successfully implementing appropriate response strategies. In this context, the NEO Physical Observations and Properties Simulation (NEOPOPS) was established, building on the success of previous international research programs dedicated to the study of NEOs (NEOShield, NEOShield-2, and NEOROCKS). NEOPOPS is an European project funded by the EU Horizon Europe Programme and implemented by ESA for the period 2025-2028. Its objectives are multiple:to efficiently organize follow-up astronomical observations of NEOs, to obtain high-quality data for deriving their physical properties, with priority given to the timely characterization of potentially hazardous objects;to significantly improve statistical analyses, modeling, and numerical simulations aimed at understanding the physical nature of NEOs, with a particular focus on small-sized objects, which are of paramount importance for designing effective mitigation measures both in space and on the ground;to foster European and international cooperation in NEO physical characterization, providing scenarios and roadmaps with the scale up the experience gained during the project to a global level;to collaborate with ESA to significantly improve public understanding and perception of the asteroid hazards, counteracting the spread of misinformation and unwarranted alarm. Our team consists of six partners from four countries (Italy, France, the Czech Republic, and UK) employing diverse and complementary observational techniques to consolidate and further enhance physical characterization of NEOs. The team also contributes to rapid-response exercises aimed at characterizing newly discovered objects, thereby addressing the challenge posed by imminent impactors. In particular, we participated in recent observational campaigns to characterize 2024 YR4 [3] and 2025 FA22 [4].The INAF-OAR is responsible for several working packages, including overall project coordination (WP1), spectroscopic observations (WP4) and rapid-response activities (WP6). In this presentation, we will describe the structure of NEOPOPS as well as its spectroscopic component. We will also present some recent results and statistics obtained during the first year of the project. Acknowledgments: The NEOPOPS observations were funded by a program of the European Union and implemented by ESA (agreement No.4000147191/25/D/MRP) ReferencesBottke W.F., Cellino A., Paolicchi P., et al., 2002, Asteroid III, University of Arizona Press, p. 3-15, 2002.Perna D., Barucci M.A., Drube L., et al., 2015, P&SS, 118, P. 311-317Devogèle, M., Hainaut, O. R., Micheli, M. et al., 2026, JAnSc, 73, 31.Ieva, S., Bourdelle de Micas, J., Farina, A. et al., in preparation

In July 2025 the third known member of the Interstellar Objects (ISOs) class, 3I/ATLAS, was discovered on its inbound orbital branch, at a heliocentric distance rh = 4.5 au. An intense world-wide campaign started immediately after the discovery and continued up to a few weeks before its perihelion passage. It was possible to depict a scenario of a cometary body redder than most of the Solar System comets, with a deep and narrow negative polarization branch, and a CO2-dominated coma. While approaching its perihelion, a rapid rise in comet’s brightness and a steep heliocentric-distance scaling for the production rates of Ni and CN were observed [1] [2] [3] [4] [5] [6] [7].Due to reciprocal positions of comet and Earth, ground-based observations through the perihelion passage (2025 October 29) were unfortunately impossible, but instead the JUICE spacecraft [8], on its cruise phase towards the Jovian system, was very well placed to observe 3I/ATLAS during those days. Therefore, an observational campaign has been designed and planned, involving several instruments onboard the spacecraft, including the JANUS visible camera [9].123 JANUS images were obtained in 5 observing slots on 2025 November 5, 6, 12, 19, and 25, using 7 filters to cover the spectral range from 340 to 1080 nm. Figure 1 shows an example of image sequence in the F01 (panchromatic) filter obtained from November 5 to November 25, while the comet’s distance from the Sun varied from 1.39 to 1.67 au and the JUICE’s distance from the comet varied from 64 to 188 million km.In this work, the JANUS images of 3I/ATLAS and the first results of the JANUS observing campaign will be presented and discussed.References: [1] Seligman D.Z., Micheli M., Farnocchia D. et al., ApJL 2025. 989, L36-L46. [2] Opitom C., Snodgrass C., Jehin E. et al., MNRAS 2025, 544, 1, L31-L36. [3] Gray Z., Bagnulo S., Borisov G. et al., ApJL 2025, 992, 2, L29-L37. [4] Cordiner M.A., Roth N.X., Kelley M.S.P. et al., ApJL 2025, 991, 2, L43-L52. [5] Rahatgaonkar R., Carvajal J.P., Puzia T.H. et al., ApJL 2025, 995, 1, L34-L46. [6] Hoogendam W.B., Shappee B.J., Wray J.J. et al., 10.48550/arXiv.2510.11779. [7] Lazzarin M., Mura A.C., La Forgia F. et al., ApJL 2026, 998, 1, L30-L35. [8] Grousset O., Dougherty M.K., Coustenis A. et al., PSS 2013, 78, 1-2. [9] Palumbo P., Roatsch T., Lara L.M. et al., SSR 221, 3, id.32

We report spectropolarimetric and broadband polarimetric observations of the near-Earth asteroid (NEA) 2025 FA22 during its close approach on 18 September 2025 (about two Moon distances). With a diameter estimated between 130 and 290 m, 2025 FA22 is among the largest NEAs observable at such proximity, prompting an International Asteroid Warning Network (IAWN) rapid-response campaign. Although early orbital solutions indicated a possible impact in 2089, further follow-up astrometric observations ruled out a collision hazard. The favourable geometry of this close encounter enabled dense coverage of the positive part of the phase-polarisation curve, from the high polarisation domain (high phase angles), to near the inversion angle where the linear polarisation fraction vanishes. The spectropolarimetric observations provided the wavelength dependence of the polarisation fraction. Using empirical relationships, an estimate of the geometric albedo could be drawn from the slope of the phase-polarisation curve at an inversion angle p _v = 0.17 ± 0.04 in the V band. This value, together with the spectropolarimetric trend, provides constraints on the taxonomic class, with the results being most consistent with an M (or Xc)-type classification. These results demonstrate the value of polarimetry and spectropolarimetry for the rapid characterisation of newly discovered NEAs in planetary defence campaigns.

The NEO Physical Observations and Properties Simulations (NEOPOPS) project, funded by the European Space Agency (ESA) and led by INAF – OAR (Observatory of Rome) is dedicated to the physical characterization of Near-Earth Objects (NEOs). The study of these objects is essential for several reasons. From a science perspective, NEOs may have played a role in delivering organic material and water to Earth (Morbidelli et al., 2000; Marty et al., 2016), and thus preserve key information about their origin and evolution from the early Solar System. From a planetary defense standpoint, NEOs can also pose a significant threat to Earth. Several events in the Earth’s history (K-Pg impact, the Chelyabinsk fall in 2013 and more recently the alert triggered by 2024 YR4 in early 2025) demonstrate that this population can cause substantial material damage and, in extreme cases, mass extinctions.To mitigate the risk posed by potentially hazardous objects, it is crucial to characterize them shortly after their discovery. The NEOPOPS project therefore conducts spectroscopic, photometric, and polarimetric observations using multiple telescopes, including the 3.58m TNG (La Palma, Spain), the 8.2m VLT (Cerro Paranal, Chile), the 1.54m Danish telescope (La Silla, Chile) and the 1.82m Copernico Telescopio (Asiago, Italy). Our goal is to constrain key physical parameters that may inform potential mitigation strategies in the event of a future impact threat.This presentation focuses on the characterization of NEOs by spectroscopy, photometry, polarimetry and rapid response. We aim to obtain monthly observations of NEOs selected according to three prioritized criteria: (1) objects that pose a potential impact risk, identified in collaboration with the NEO Coordination Center (NEOCC, ESA-ESRIN), which issues alerts when a threat is detected; (2) NEOs that are targets of upcoming space missions; and (3) recently discovered NEOs, which are particularly challenging to observe because their visibility window may last only few weeks, after which they can remain unobservable for decades. The spectra obtained provide constraints on surface composition, possible surface heterogeneity, and other physical properties, and are shared across NEOPOPS observer team to enable a comprehensive characterization of each object.For the rapid-response observations, the goal is to provide rapid, multi-technique observations to derive critical parameters relevant to impact mitigation planning. In the event of an alert, all the observing teams are mobilized to observe the object as quickly as possible. Triggered-alert objects may become unobservable shortly after discovery, often well before their predicted virtual impact date. In 2025, four alerts were issued, 2024 YR4, 2025 FA22, 2025 SC5, and 2025 VP2, with Torino Scale (Binzel et al., 2000) values ranging from 1 to 3. These real-case scenarios allowed us to test and validate our rapid response procedures and to derive key parameters, such as albedo, rotational period estimates, and surface composition.

We present spectroscopic observations of the third interstellar comet 3I/ATLAS obtained with the DOLORES instrument on the 3.58 m Telescopio Nazionale Galileo on 2025 August 16 ( r _h = 2.98 au). The spectrum revealed a red slope of 12.68% ± 0.05%/1000 Å across the 5000–8000 Å range, consistent with previous findings. Observations show the CN outgassing violet band, which yields a production rate of (4.28 ± 0.83) · 10 ²³ mol s ⁻¹ . We derived upper limits for C ₂ and C ₃ production rates since no clear detection was possible and used those to compute C ₂ /CN and C ₃ /CN ratios. The resulting, notably low, values of −0.86 and −1.47, respectively, for C ₂ /CN and C ₃ /CN ratios classify 3I as a strongly carbon-chain depleted comet in the preperihelion orbit. Notably, recent postperihelion observations found a typical solar system cometary composition, probably suggesting new innermost material being exposed to solar radiation.

We report ejecta mass estimates produced by the Double Asteroid Redirection Test impact with Dimorphos, the secondary of the Didymos asteroid binary system. This first demonstration of an asteroid deflection technique was witnessed by the Light Italian Cubesat for Imaging of Asteroids (LICIACube). The LICIACube Unit Key Explorer (LUKE) RGB camera images are used to estimate the ejecta mass, critical to understanding the impact conditions and physical properties of the asteroid. This requires realistic scattering properties for the ejecta particles, which were obtained from model and laboratory scattering analog particles (sizes μm to ∼1 cm). The particle size distribution (PSD) of ejecta is constrained from a series of 18 images acquired at widely separated phase angles (50 . ° 6 to 110 . ° 2) using the size dependence of the analog scattering phase functions. Total plume radiance in the LUKE RGB channels is determined by spatially integrating over the field of view in each image. Plume radiances are then used to retrieve ejecta mass assuming an optically thin plume, giving lower limit estimates of 0.85 to 1.19 × 10⁷ kg. Results indicate that the PSD of ejecta in the nascent plume follows a single power-law coefficient (k ≈ −2.5), rather than the broken power law inferred from later observations. Using a single, high signal-to-noise image, the observed areal mass-brightness relation is extrapolated inward, yielding an increase of ≈77% for ejecta mass in the optically thick inner region. Our ejecta mass estimates are consistent with Dimorphos having weak cohesive strength (<5000 Pa but more likely ∼50 Pa).

Introduction: The Light Italian Cubesat for Imaging of Asteroids (LICIACube) [1] is a 6U CubeSat developed for the Italian Space Agency (ASI). LICIACube was carried by NASA’s Double Asteroid Redirection Test (DART) spacecraft and was deployed 15 days in advance of DART’s impact with the asteroid Dimorphos [2] to acquire images of the event and its effects. During its post-impact flyby, LICIACube achieved a minimum distance of approximately 58 km from Dimorphos and returned more than 400 scientific images, obtaining a unique view of the event [3]. The DART/LICIACube mission: The Double Asteroid Redirection Test (DART was launched on 24 November 2021 to perform the first test of a planetary defence mitigation technology, redirecting the asteroid Dimorphos, the small satellite of the binary Near Earth Asteroid (NEA) (65803) Didymos [4], via a kinetic impact. During the 9.5-month cruise, LICIACube was hosted on the DART spacecraft. On 11 September 2022, fifteen days before DART’s kinetic impact, LICIACube was released and autonomously continued its track toward the binary asteroid system. LICIACube was equipped with two different cameras, LICIACube Explorer Imaging for Asteroid (LEIA) and LICIACube Unit Key Explorer (LUKE) [1]. The science phase started 71 seconds before the nominal impact time, when LICIACube was about 1400 km from Dimorphos. The science phase of LUKE started 29 seconds after the impact, acquiring triplets of images with different exposure times. LICIACube followed the target and the evolution of the system up to 320 seconds after the impact. The spacecraft’s Closest Approach (CA) occurred 167 s after the impact.The LICIACube images: LEIA images testified the DART impact by an increase in the luminosity of the target, while LUKE images revealed that the DART impact into Dimorphos generated a cone of ejected material with a large aperture angle [3]. In the LICIACube viewing geometry, the produced effects were clearly seen in both pre-CA and post-CA LUKE images (Fig. 1). The ejecta plume shows a complex and inhomogeneous structure, characterised by filaments, dust grains, and single or clustered boulders, providing insights into the properties of the ejecta, as well as the nature of Dimorphos. Measurements from the LICIACube images constrain the asteroid shape [5], and the 3D shape of the cone plume [6]. Moreover, they feed into the calculations of the momentum transferred to Dimorphos by DART’s kinetic impact [7]. The accomplishments of LICIACube demonstrated the compelling potential for future deep-space CubeSats.Figure 1. Images obtained by LUKE pre-CA and post-CA (Credits: ASI/NASA) Acknowledgments: The LICIACube team acknowledges financial support from Agenzia Spa-ziale Italiana (ASI, contract No. 2019-31-HH.0 CUP F84I190012600). References: [1] Dotto E., et al. (2021) PSS 199, id. 105185. [2] Daly R.T., et al. (2023) Nature 616 (7957), 443. [3] Dotto E., et al. (2024) Nature 627, 505. [4] Rivkin A.S., et al. (2021) PSJ 2(5), id.173. [5] Zinzi A., et al. (2023) PSJ 5, id.103. [6] De-shapriya J.D.P., et al. (2023) PSJ 4 id.231. [7] Cheng A.F., et al. (2023) Nature, 616(7957), 457.

Introduction: Near-Earth Objects (NEOs) provide a window into the smallest population of asteroids and comets that originated from more distant regions of the Solar System. Most of them are product of collisional processes at various stages of the Solar System's evolution, thus important for probing compositions that may have contributed to the delivery of water and organics to Earth and the inner planets.As NEO discoveries increase—currently at about 3,000 objects per year—the majority are not followed up with physical characterization. These properties would offer insights into their internal structure and material strength in the event of atmospheric entry [1,2], not to mention their potential as targets for future mining, exploration, and planetary defense missions [3]. Therefore, anticipating a rise in new discoveries following the start of LSST operations, we initiated a year-long, monthly photometric observation campaign of NEOs discovered in the past two years (2022–2023) and visible with the VLT Survey Telescope (VST) at Cerro Paranal. The main instrument on the VST is OmegaCAM, a multi-filter, 32-CCD camera with a Field of View (FoV) of 1 square degree [4]. This capability enables the tracking of very fast-moving NEOs and also brings important collateral science: many other small bodies can be observed simultaneously. These secondary targets are identified and analyzed to enhance their characterization and astrometric positions.Observations: The observations were carried between February to September 2023, two monthly nights. The targets were observed cycling through SDSS r’i’z’g’r’ filters in exposure times of 10 to 30s depending on the observational conditions. Every target was observed for 1 hour. In total, we acquired 5519 image cubes covering 72 NEAs, and possibly 5 to 10 times this number in SSO in the background depending on the pointing region. The magnitude limit is estimated to r’=21.5 for SNR=3 and exposure time of 20s. The cubes are radiometrically calibrated in the Astro-Wise environment through the VST pipeline available by INAF-OAC [5]. The final products are single Mosaics in absolute Jansky flux and astrometrics. We are also provided with a list of sources measured with SExtractor. See Fig. 1 for an example of final product, where the main target and secondary targets are visible.Methodology: The analysis is carried through procedures developed in Python3 language and the use of Scikit-image, Astropy, Photutils, and Astroquery libraries, and ordered in three steps:1. Querying SSOs and Fixed Sources in the Field. We catalog all fixed and moving sources over mag=23 for identification of the main and secondary targets, and obtaining the photometry of field stars for flux quality check. We also operate a check on the celestial coordinate and correct any miss-offsets present. The moving object ephemeris is obtained from OBSPM/IMCEE service and the fixed sources from several catalogs bundled under the Astropy/VO service.2. Target Tracking, Cube alignment, stacking. We crop all loci of 0.04°x0.04° from the field that might show potential SSOs, and then align it according to Sky-Fixed and SSO-fixed coordinates. Then fixed sources are removed, we applied Hough Transform [7] to detect linear tracks related to SSO apparent motion. Then, the cube is centered onto the target, and then a stacked cube product is provided as well.3. Aperture, Lorenz and PSF Photometry. Photometry for the target and field stars are provided through aperture, Lorenz fitting, and 2D PSF photometry analysis. We also check for signs of fast rotation throughout the image sequences. We then compare the field star photometry with SDSS and VST/Atlas sources to cross-check the flux quality [8,9].Preliminary Results and Future Steps: To date, data reduction has been completed for the first 4 observing months and for all 30 primary targets and secondary objects under exposure time ≥ 20s (the example of a section of a light-curve in Fig. 2). The color analysis is concluded for the March 2023 run, the results (Fig. 3) show that awhile the asteroids cluster around the feature and featureless loci, we have samples of redder and bluer asteroids, generally associated to organic or carbon-rich bulk compositions.In September 2024, new NEOVST observations have been scheduled between February 2025 and September 2025. We are now focusing on scattered monthly observations of newly discovered NEOs, with exposure times of 30s (r’) to 50s (z’), and two sequences of 1 hrs each target. We now aim to improve the signal of the background stars for better astrometric positioning, and better sampling for the phase and rotational curves by compiling data from two separated nights. (a) (b)Fig.1: (a) Full mosaic of 32 CCDs for the acquisition of 2023-02-04 UT 05:15:09 in SDSS r’ for the main target NEA 2022 YM5. (b) The main target (magenta) and secondary targets (yellow) in the FOV. Fig.2: A sequence of AB magnitudes obtained for the asteroid 2001 EV2 for the run of March 2023. The error bars are within the symbol size.Fig.3: SDSS color mosaic of the asteroids observed in the March 2023 run (7NEAs+15MBAs). The data is overlay by the approx. loci of “S-like” and “C-like” asteroids. Many objects lack the SDSS z’ magnitude due to the weaker band efficiency.References: [1]Perna,D.,Barucci,M.A.,&Fulchignoni,M. 2013, A&ARv,21,65. [2]Perna,D.,Dotto,E.,Ieva,S., et al. 2016, AJ 151,11. [3]Sanchez,J.-P., & McInnes,C.R. 2013, ed. V.Badescu, 439 [4]K.Konrad,R.Bender,E.Cappellaro, et al. 2004, GIA 5492, 484–494. [5]McFarland,J.P.,Verdoes-Kleijn,G., Sikkema,G. et al. 2013, ExpAstron 35, 45–78. [6]Bertin,E.&Arnouts,S. 1996, A&ASupp 317, 393. [7]P.V.C.Hough. 1959, Proc.Int.Conf. High Energy Accelerators and Instrumentation. [8] Gunn,J. E.; Siegmund,W.A.; Mannery,E.J., et al. 2006, ApJ 131,2332–2359....

The ESA JUICE mission. ESA’s Jupiter Icy Moons Explorer (JUICE) [1] has been successfully launched from Europe's Spaceport in French Guiana on April 14th, 2023. A suite of remote sensing, geophysical and in situ instruments are accommodated onboard, with the aim to i) explore Jupiter’s complex environment in depth, ii) study the wider Jupiter system as an archetype for gas giants across the Universe, and iii) characterize in detail the three large ocean-bearing moons (Ganymede, Callisto and Europa), as both planetary objects and possible astrobiological habitats. Before reaching the Jovian system in July 2031, JUICE will cruise ~8 years inside the inner Solar System (see Figure 1), performing 4 planetary fly-bys (the first one ever attempted with both the Moon and Earth, then with Venus and two more with Earth). JUICE instrument operations during such fly-bys are heavily constrained for technical reasons and to give full priority to navigation and mission safety. Nevertheless, such events are good opportunities to perform calibration checks and experience typical fly-by operations that will be undertaken with Galilean satellites. In addition to these planned fly-bys, the JUICE spacecraft will be routinely operated in specific time windows to perform instruments and probe “checkout operations” (see Figure 2). In particular, some of these “checkout windows” without attitude constraints (i.e., above 1.4 AU Sun distance) can be exploited to optimize observation of small bodies of our Solar System, in view of similar observations to be performed on minor targets in the Jupiter system. These data will therefore increase the scientific output of the whole mission at no resources expense, by properly choosing the pointing towards targets of planetary interest. These observations, if properly planned, could significantly contribute to explore the Cosmic Vision’s main theme “How does the Solar System work?” The JANUS instrument onboard JUICE. The JANUS (Jovis, Amorum ac Natorum Undique Scrutator) instrument [2] onboard JUICE is the multispectral camera enabling imaging in the 340-1080 nm wavelength range. JANUS allows imaging of many different targets: from the icy satellites, to Io, to small inner and irregular moons, the rings and Jupiter itself. While in the Jupiter system, the JUICE trajectory will allow icy Galilean satellites observations down to closest approaches of a few hundred km, resulting in spatial sampling up to a few m/pixel. All the other targets will be observed from distances above a few 105 km, i.e. spatial sampling above several km/pixel. 13 filters from the near ultraviolet to the near infrared will guarantee good spectral coverage with bandwidths from several tens of nm down to 10 nm. Science during checkout windows and coordination with ground-based campaigns. We propose to exploit the checkout windows during the JUICE cruise phase to perform cometary science with JANUS, adding no cost science to the plans of testing instrument’s capability to detect faint sources (representative for exospheres and rings in Jupiter system) and to characterize unresolved objects (representative for Jupiter small moons). Among small bodies orbiting our Solar System, comets are thought to provide the most direct information on how planets form in all protoplanetary disks [3]. The observation of comets provides key information to investigate the processes of formation and evolution of pebbles forming planetesimals at different heliocentric distance of the primordial Solar Nebula, the pebbles themselves probably originating from different regions of the solar protoplanetary disk [4]. JANUS checkout pointing campaigns of comets of several dynamical groups could allow these targets to be observed at phase angles (i.e., angle Sun-Target-Observer) hardly available from Earth. In particular, optical imagery of cometary coma as a function of phase angle has a key importance in investigating the intimate nature of cometary dust [5]: size, size distribution, shape, and composition of dust particles can be investigated by means of observations taken in different broadband filters as those potentially provided by JANUS, and by means of comparison with data obtained e.g. with ground-based telescopes, with different observing geometries. Here we present the results of a “test” we performed for the Checkout #4, foreseen for the week of 23 February 2026, where the Pointing Campaign #1 will be executed and the spacecraft pointing will not undergo strict thermal constraints as during cruising in the inner Solar System. To this aim, we designed a specific tool, J-SCOUT (Search for Cruise-phase Observation Utility Tool) [6] to query the JPL Horizon database [7] and take an “instant picture” of the small bodies complex within the Solar System at the checkout date(s), considering the latest Consolidated Report on Mission Analysis (CreMA 5.0b23) as the baseline mission profile. We designed the possibility to limit the query to the “active bodies” (as defined in the JPL Horizon Database), resulting in investigations of comets pertaining to 6 different dynamical categories. This allowed us to derive a list of potential “campaign cometary targets” for Checkout#4, which will be used as a “testbed” for such an operational plan, aimed at nominal instrument functional and performance verification activities during cruise. The Checkout #4 outcomes will be used to prepare for next checkout(s), for which J-SCOUT will be used to obtain a new list of “JUICE targets” that will be proposed for a campaign of quasi-contemporary, possibly multi-telescope ground-based observations, hence enhancing the synergy among space missions and ground-based telescopes. References. [1] Grasset et al., 2013, PSS 78, 1. [2] Palumbo P. et al., 2025, SSR 221, 3, id. 32. [3] Blum J. et al., 2017, MNRAS 469:...