VADER: Probing the Dark Side of Dimorphos with LICIACube LUKE

The ASI cubesat LICIACube has been part of the first planetary defense mission DART, having among its scopes to complement the DRACO images to better constrain the Dimorphos shape. LICIACube had two different cameras, LEIA and LUKE, and to accomplish its goal, it exploited the unique possibility of acquiring images of the Dimorphos hemisphere not seen by DART from a vantage point of view, in both time and space. This work is indeed aimed at constraining the tridimensional shape of Dimorphos, starting from both LUKE images of the nonimpacted hemisphere of Dimorphos and the results obtained by DART looking at the impacted hemisphere. To this aim, we developed a semiautomatic Computer Vision algorithm, named VADER, able to identify objects of interest on the basis of physical characteristics, subsequently used as input to retrieve the shape of the ellipse projected in the LUKE images analyzed. Thanks to this shape, we then extracted information about the Dimorphos ellipsoid by applying a series of quantitative geometric considerations. Although the solution space coming from this analysis includes the triaxial ellipsoid found by using DART images, we cannot discard the possibility that Dimorphos has a more elongated shape, more similar to what is expected from previous theories and observations. The result of our work seems therefore to emphasize the unique value of the LICIACube mission and its images, making even clearer the need of having different points of view to accurately define the shape of an asteroid.This work was supported by the Italian Space Agency (ASI) within the LICIACube project (ASI-INAF agreement AC No. 2019-31-HH.0) and by the DART mission, NASA contract 80MSFC20D0004

Achievement of the planetary defense investigations of the Double Asteroid Redirection Test (DART) mission

NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, and the mission's Level 1 requirements guided its planetary defense investigations. Here, we summarize DART's achievement of those requirements. On 2022 September 26, the DART spacecraft impacted Dimorphos, the secondary member of the Didymos near-Earth asteroid binary system, demonstrating an autonomously navigated kinetic impact into an asteroid with limited prior knowledge for planetary defense. Months of subsequent Earth-based observations showed that the binary orbital period was changed by –33.24 minutes, with two independent analysis methods each reporting a 1σ uncertainty of 1.4 s. Dynamical models determined that the momentum enhancement factor, β, resulting from DART's kinetic impact test is between 2.4 and 4.9, depending on the mass of Dimorphos, which remains the largest source of uncertainty. Over five dozen telescopes across the globe and in space, along with the Light Italian CubeSat for Imaging of Asteroids, have contributed to DART's investigations. These combined investigations have addressed topics related to the ejecta, dynamics, impact event, and properties of both asteroids in the binary system. A year following DART's successful impact into Dimorphos, the mission has achieved its planetary defense requirements, although work to further understand DART's kinetic impact test and the Didymos system will continue. In particular, ESA's Hera mission is planned to perform extensive measurements in 2027 during its rendezvous with the Didymos–Dimorphos system, building on DART to advance our knowledge and continue the ongoing international collaboration for planetary defense

Analisi e Studio dei Minerali Idrati su Marte: il caso del bacino lacustre di Eridania.

Durante il Noachiano, Marte disponeva di un’atmosfera, di un campo magnetico molto forte e di uno dei sistemi vulcanici piu` grandi e attivi di tutto il Sistema Solare. Il Pianeta Rosso era quindi caratterizzato dalla presenza di acqua liquida sulla sua su- perficie portando alla formazione di antichi laghi, alvei fluviali, delta sedimentari ed oceani. Grazie all’azione dell’acqua sulle rocce che formavano la crosta primordiale marziana, si sono potuti formare i minerali idrati, la prova mineralogica della presen- za di acqua liquida sul pianeta. In questo lavoro di tesi, dopo aver brevemente descritto la storia geologica di Marte, si descrivono i principali minerali idrati conosciuti sulla Terra, in che situazione fisico-chimica essi si sono formati, e come questi possano essere ”collegati” all’am- biente marziano. La loro identificazione su Marte e` avvenuta grazie allo spettrometro ad immagini CRISM, a bordo della sonda marziana NASA Mars Reconnaissance Or- biter. Conoscendo le caratteristiche in presenza delle quali si formano certi minerali, e ritrovando questi minerali su Marte, e` possibile ricostruirne la storia geologica del- l’ambiente in cui si trovavano. Utilizzando poi il software di analisi spettrale ENVI, e` stato possibile elaborare un data-cube della zona di Eridania su Marte, quello che si pensa potesse essere uno dei piu` grandi paleo-lagi presenti sulla superficie del pianeta. Dall’analisi compiuta, si ricavano poi gli andamenti spettrali (range 0.5-2.5 micron) di alcuni fillosilicati, e le loro firme spettrali , per poi ricostruire quali potessero essere le condizioni ambientali nell’estremita` nord-est di Eridania circa 3.5 miliardi di anni fa

Analysis of the OMEGA 0.4-2.5 μm spectra of the martian satellite Phobos

reservedThis thesis work starts with a description of asteroids taxonomy and meteorites classification, followed by an overview of the main physical and spectral characteristics of the martian satellite Phobos, with a review of the main scientific results obtained until now. The main problem is to understand Phobos' origin. There are a few main theories proposed, but so far no one has been completely ruled out: Capture Theory, Co-accretion with Mars, Impact Theory. For this reason, studies of Phobos' composition and mineralogy have been conducted, in order to clarify how the moon could have been formed. We present an analysis of four OMEGA data-cubes with the software ENVI, in the spectral region 0.4-2.5 μm, in order to determine some compositional constraints or spectral characteristics that could be used to find a meteoric or asteroidal analogue. Linear mathematical combinations of laboratory spectra are proposed and compared with Phobos' spectra, in order to find a laboratory analogue that could mimic Phobos' spectral response.This thesis work starts with a description of asteroids taxonomy and meteorites classification, followed by an overview of the main physical and spectral characteristics of the martian satellite Phobos, with a review of the main scientific results obtained until now. The main problem is to understand Phobos' origin. There are a few main theories proposed, but so far no one has been completely ruled out: Capture Theory, Co-accretion with Mars, Impact Theory. For this reason, studies of Phobos' composition and mineralogy have been conducted, in order to clarify how the moon could have been formed. We present an analysis of four OMEGA data-cubes with the software ENVI, in the spectral region 0.4-2.5 μm, in order to determine some compositional constraints or spectral characteristics that could be used to find a meteoric or asteroidal analogue. Linear mathematical combinations of laboratory spectra are proposed and compared with Phobos' spectra, in order to find a laboratory analogue that could mimic Phobos' spectral response

Mass movement reconstruction and boulder size-frequency distribution of the Simud Vallis landslide, Mars

International audienc

Modelling reconstruction and boulder size-frequency distribution of a young (<5 Myr) landslide located in Simud Vallis floor, Mars

International audienc

Achievement of the Planetary Defense Investigations of the Double Asteroid Redirection Test (DART) Mission

Abstract NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, and the mission's Level 1 requirements guided its planetary defense investigations. Here, we summarize DART's achievement of those requirements. On 2022 September 26, the DART spacecraft impacted Dimorphos, the secondary member of the Didymos near-Earth asteroid binary system, demonstrating an autonomously navigated kinetic impact into an asteroid with limited prior knowledge for planetary defense. Months of subsequent Earth-based observations showed that the binary orbital period was changed by –33.24 minutes, with two independent analysis methods each reporting a 1σ uncertainty of 1.4 s. Dynamical models determined that the momentum enhancement factor, β, resulting from DART's kinetic impact test is between 2.4 and 4.9, depending on the mass of Dimorphos, which remains the largest source of uncertainty. Over five dozen telescopes across the globe and in space, along with the Light Italian CubeSat for Imaging of Asteroids, have contributed to DART's investigations. These combined investigations have addressed topics related to the ejecta, dynamics, impact event, and properties of both asteroids in the binary system. A year following DART's successful impact into Dimorphos, the mission has achieved its planetary defense requirements, although work to further understand DART's kinetic impact test and the Didymos system will continue. In particular, ESA's Hera mission is planned to perform extensive measurements in 2027 during its rendezvous with the Didymos–Dimorphos system, building on DART to advance our knowledge and continue the ongoing international collaboration for planetary defense.</jats:p