arXiv subjects

M. Fenucci

Publications and source records attributed to M. Fenucci.

5 recordsLinked to original sources

arXiv2026

Origin of asteroid (469219) Kamo`oalewa: the main asteroid belt or the Giordano Bruno crater on the Moon?

Asteroid Kamo`oalewa is the target of the Tianwen-2 sample-return mission by CNSA. Because of its orbit and its spectral properties, it was proposed that Kamo`oalewa originated from the Moon as impact ejecta, possibly from the Giordano Bruno crater. We aim at estimating the relative contribution of Kamo`oalewa-like objects originating from the general near-Earth asteroid (NEA) population which originated in the main asteroid belt, and compare it with the relative contribution of Giordano Bruno ejecta. We first estimate the average fraction of quasi-satellite orbits at any given time. By using recently developed NEA population models, we extract the expected number of Earth co-orbitals of the same size of Kamo`oalewa, and then get an estimate of the average number of Kamo`oalewa-like objects using the fraction computed before. Similarly, we obtain an estimate for the number of Kamo`oalewa-like objects that may originate as ejecta from the Giordano Bruno impact. We also performed survey simulations to estimate their efficiency in the detection of Kamo`oalewa-like objects. We found that the main belt accounts for 1.23 \pm 0.13 Kamo`oalewa-like objects on average. The expected number of Kamo`oalewa-like objects originated as Giordano Bruno ejecta is 0.042, which is more than order of magnitude smaller. We found a discovery efficiency of Earth quasi-satellites between 95% and 70% for absolute magnitude between 22 and 25 for the Pan-STARRS survey, and population models show that this is in agreement with the known population. The Vera Rubin Observatory should reach an efficiency of 92% down to absolute magnitude 25. These estimates show that population models of NEAs are capable to account for Kamo`oalewa-like objects, thus supporting the hypothesis that that Kamo'oalewa originated from the main belt. This will be further investigated by the in-situ exploration of the Tianwen-2 mission.

astro-ph.EP↗

arXiv2024

Long-term orbital evolution of Dimorphos boulders and implications on the origin of meteorites

By using recent observations of the Dydimos-Dimorphos system from the Hubble Space Telescope, 37 boulders with a size of 4 to 7 meters ejected from the system during the impact with the DART spacecraft were identified. In this work, we studied the orbital evolution of a swarm of boulders with a similar size to that of the detected ones. By using recent estimates for the ejection velocity of the boulders, we numerically propagated the dynamics of the swarm for 20 kyr in the future. We found that the ejection velocities and the non-gravitational effects are not strong enough to change the secular evolution significantly. The minimum orbit intersection distance (MOID) with the Earth will be reached in about 2.5 kyr, but it will not fall below 0.02 au. On the contrary, the Mars MOID will be very small in four instances, two near 6 kyr and the other two near 15 kyr. Therefore, there may be a chance for them to impact Mars in the future. Given the rarefaction of the Martian atmosphere, we expect the boulders to arrive intact on the ground and excavate a small impact crater. The results presented here provide a further indication that some meteorites found on Earth originated in collisions of $\sim$100 m near-Earth asteroids with projectiles of $\sim$1 m in size.

astro-ph.EP↗

arXiv2023

Maps of secular resonances in the NEO region

Context. From numerical simulations, it is known that some secular resonances may affect the motion of near-Earth objects (NEOs). However, the specific location of the secular resonance inside the NEO region is not fully known, because the methods previously used to predict their location can not be used for highly eccentric orbits and when the NEOs cross the orbits of the planets. Aims. In this paper, we aim to map the secular resonances with the planets from Venus to Saturn in the NEO region, even for high values of the eccentricity. Methods. We used an averaged semi-analytical model that can deal with orbit crossing singularities for the computation of the secular dynamics of NEOs, from which we can obtain suitable proper elements and proper frequencies. Then, we computed the proper frequencies over a uniform grid in the proper elements space. Secular resonances are thus located by the level curves corresponding to the proper frequencies of the planets. Results. We determined the location of the secular resonances with the planets from Venus to Saturn, showing that they appear well inside the NEO region. By using full numerical N-body simulations we also showed that the location predicted by our method is fairly accurate. Finally, we provided some indications about possible dynamical paths inside the NEO region, due to the presence of secular resonances.

astro-ph.EP↗

arXiv2022

Proper elements for resonant planet-crossing asteroids

Proper elements are quasi-integrals of motion, meaning that they can be considered constant over a certain timespan, and they permit to describe the long-term evolution with a few parameters. Near-Earth objects (NEOs) generally have a large eccentricity and therefore they can cross the orbits of the planets. Moreover, some of them are known to be currently in a mean-motion resonance with a planet. Thus, the methods previously used for the computation of main-belt asteroid proper elements are not appropriate for such objects. In this paper, we introduce a technique for the computation of proper elements of planet-crossing asteroids that are in a mean-motion resonance with a planet. First, we numerically average the Hamiltonian over the fast angles while keeping all the resonant terms, and we describe how to continue a solution beyond orbit crossing singularities. Proper elements are then extracted from a frequency analysis of the averaged orbit-crossing solutions. We give proper elements of some known resonant NEOs, and provide comparisons with non-resonant models. These examples show that it is necessary to take into account the effect of the resonance for the computation of accurate proper elements.

astro-ph.EP↗

arXiv2020

Long-term evolution of the Galilean satellites: the capture of Callisto into resonance

Context. The strong tidal dissipation in the couple Jupiter-Io is spread to all the moons involved in the Laplace resonance (Io, Europa, and Ganymede), leading to a migration of their orbits. Aims. We aim to characterize the future behavior of the Galilean satellites over the Solar System lifetime and to quantify the stability of the Laplace resonance. Since tidal dissipation makes possible the exit from the current resonances or capture into new ones, we investigate the capture of Callisto into resonance. Methods. We perform hundreds of propagations using an improved version of a recent semi-analytical model. As Ganymede moves outwards, it approaches the 2:1 resonance with Callisto, inducing a temporary chaotic motion in the system. For this reason, we draw a statistical picture of the outcome of the resonant encounter. Results. The system can settle into two distinct outcomes: A) a chain of three 2:1 two-body resonances (Io-Europa, Europa-Ganymede and Ganymede-Callisto), or B) a resonant chain involving the 2:1 two-body resonance Io-Europa plus at least one pure 4:2:1 three-body resonance, most frequently between Europa, Ganymede and Callisto. In case A (56\% of the simulations), the Laplace resonance is always preserved and the eccentricities remain confined to small values below 0.01. In case B (44\% of the simulations), the Laplace resonance is generally disrupted and the eccentricities of Ganymede and Callisto can increase up to about 0.1, making this configuration unstable and driving the system into new resonances. Conclusion. From our results, the capture of Callisto into resonance appears to be extremely likely (100\% of our simulations). Assuming the most recent estimate of the dissipation between Io and Jupiter, the resonant encounter happens at about 1.5 Gyrs from now. Therefore, the stability of the Laplace resonance is guaranteed at least up to about 1.5 Gyrs.

astro-ph.EP↗