Near-Earth objects (NEOs), due to their proximity to our planet, represent one of the most accessible bodies in the whole Solar System. Their investigation, other than providing vital information to planetary formation and water delivery, is compelling due to the hazard these bodies pose to human civilization. To this purpose, the NASA Double Asteroid Redirection Test (DART) has been approved to be the first demonstration of kinetic impactor as a asteroid hazard mitigation. The DART spacecraft, to be launched in mid-2021, will impact Dimorphos, the secondary member of the Didymos binary asteroid system, in late 2022. Hosted as a piggyback during the 15 months of DART interplanetary cruise and released ten days before the DART impact there will also be LICIACube, the Light Italian Cubesat for Imaging of Asteroids, a 6U cubesat space mission supported by the Italian Space Agency (ASI). The Italian LICIACube consortium (supported by ASI) is currently involved in an international observing campaign, with the aim to characterize at best the Didymos system before and after the impact. The limited data available for the binary NEO (65803) Didymos suggest a possible silicate composition, similar to ordinary chondrites, the most common meteorites retrieved on Earth. Remote characterization of the system is crucial due to its binary nature, in order to disentangle the contribution of the primary from the secondary body and asses the heterogeneity of the surface composition. Due to favorable geometric observing conditions in 2021 (i.e. when the Earth and Sun will be close to the orbital plane of the system) "mutual events", namely occultations and eclipses, will be observed from Earth. The detailed analysis of such events could help assess the contribution of the Dimorphos on the physical characterization of Didymos. To this purpose, during the next observable window in early 2021, the last before the DART impact, we plan to physically characterize the Didymos system, mainly through visible spectroscopy @TNG at different rotational phases. In order to correlate those spectra with the location on the surface of Didymos, and examine the possible contribution of Dimorphos during mutual events, the spectra will be phase-correlated with lightcurves obtained during the same period. In addition, we will also compare data obtained in 2021 with spectra of the binary system obtained during the last observational windows (2003 and 2019) to look for long-term variability. This research was supported by the Italian Space Agency (ASI) within the LICIACube project (ASI-INAF agreement AC n. 2019-31-HH.0).
Spectroscopic Characterization of the Didymos System, Target of the Kinetic Impactor Dart/liciacube Mission
Palumbo, P.;Bertini, I.;
2021-01-01
Abstract
Near-Earth objects (NEOs), due to their proximity to our planet, represent one of the most accessible bodies in the whole Solar System. Their investigation, other than providing vital information to planetary formation and water delivery, is compelling due to the hazard these bodies pose to human civilization. To this purpose, the NASA Double Asteroid Redirection Test (DART) has been approved to be the first demonstration of kinetic impactor as a asteroid hazard mitigation. The DART spacecraft, to be launched in mid-2021, will impact Dimorphos, the secondary member of the Didymos binary asteroid system, in late 2022. Hosted as a piggyback during the 15 months of DART interplanetary cruise and released ten days before the DART impact there will also be LICIACube, the Light Italian Cubesat for Imaging of Asteroids, a 6U cubesat space mission supported by the Italian Space Agency (ASI). The Italian LICIACube consortium (supported by ASI) is currently involved in an international observing campaign, with the aim to characterize at best the Didymos system before and after the impact. The limited data available for the binary NEO (65803) Didymos suggest a possible silicate composition, similar to ordinary chondrites, the most common meteorites retrieved on Earth. Remote characterization of the system is crucial due to its binary nature, in order to disentangle the contribution of the primary from the secondary body and asses the heterogeneity of the surface composition. Due to favorable geometric observing conditions in 2021 (i.e. when the Earth and Sun will be close to the orbital plane of the system) "mutual events", namely occultations and eclipses, will be observed from Earth. The detailed analysis of such events could help assess the contribution of the Dimorphos on the physical characterization of Didymos. To this purpose, during the next observable window in early 2021, the last before the DART impact, we plan to physically characterize the Didymos system, mainly through visible spectroscopy @TNG at different rotational phases. In order to correlate those spectra with the location on the surface of Didymos, and examine the possible contribution of Dimorphos during mutual events, the spectra will be phase-correlated with lightcurves obtained during the same period. In addition, we will also compare data obtained in 2021 with spectra of the binary system obtained during the last observational windows (2003 and 2019) to look for long-term variability. This research was supported by the Italian Space Agency (ASI) within the LICIACube project (ASI-INAF agreement AC n. 2019-31-HH.0).I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
