A chemical survey of exoplanets with ARIEL

Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

Studio teorico e sperimentale di una interfaccia per il comando di dispositivi robotici

La tecnologia è una componente sempre più attiva in molti aspetti della società moderna ed ha un importante impatto su molti aspetti della nostra attività sociale e professionale. L’interazione dell’utente con la tecnologia diventa un elemento fondamentale per la sua accessibilità e diffusione. I sistemi di interfacciamento la persona e la macchina hanno quindi il duplice fine di conferire un maggior numero di informazioni all’utente, modificandole in funzione delle sue esigenze e secondo i parametri fondamentali per l’utilizzo delle macchine e di tradurre le intenzioni del soggetto stesso in comandi per la macchina. Su questo scenario in continua evoluzione, è stato focalizzato il presente lavoro di tesi. La possibilità di realizzare una interfaccia indossabile, utilizzabile sia in campo riabilitativo che come dispositivo di comando, ha richiesto uno studio approfondito sulle interfacce indossabili ed esoscheletriche, non tralasciando altre tipologie di sistemi di comunicazione persona/macchina. Partendo da uno studio generale sullo stato dell’arte delle interfacce indirette e analizzando sistemi robotici indossabili, si è cercato di trovare una soluzione che fosse semplice da utilizzare e da comprendere per un utente. Rispettando esigenze di minima invasività, è stato concepito e realizzato un sistema che riesce, sfruttando il naturale movimento delle dita della mano, a comandare tramite semplici segnali di on/off, ottenuti da sensori di accelerazione, strutture robotiche e dispositivi elettronici. L’utilizzo di questi sensori, semplici e poco costosi, che godono di una spiccata sensibilità per il modulo dell’accelerazione, ha portato a studiare la cinematica e la dinamica del dito sul quale il dispositivo realizzato viene fissato e a definire i parametri di interesse che dovevano essere rilevati dagli accelerometri e comparati con una soglia di riferimento

How safe are service robots in urban environments? Bullying a robot

This paper describes and discusses the preliminary results of a behavioural study on robot social acceptability, which was carried out during a public demonstration in South Korea. Data was collected by means of direct observation of people behaviour during interaction with robots. The most interesting result to emerge is that of young people: they tended to react to the robots presence with extreme curiosity and, quite often, to treat them aggressively. In this paper, the word bullying is used to describe any kind of improper and violent behaviour, intended to cause damages or impede the robot operation. It is the authors' opinion that if not tackled appropriately, abuses towards robots may become a serious hindrance to their future deployment, and safety. Hence, the necessity to tackle this issue with dedicated solutions during the early phases of design

A vestibular interface for natural control of steering locomotion of robotic artifacts: preliminary experiments with a robotic endoscope, Springer Tracts on Advanced Robotics

Abstract. This work addresses the problem of developing novel interfaces for robotic systems that can allow the most natural transmission of control commands and sensory information, in the two directions. A novel approach to the development of natural interfaces is based on the detection of the human's motion intention, instead of the movement itself, as in traditional interfaces. Based on recent findings in neuroscience, the intention can be detected from anticipatory movements that naturally accompany more complex motor behaviors. This work is aimed at validating the hypothesis that head movements can be used to detect, slightly in advance, a person's intention to execute a steering during locomotion, and that a natural interface can be developed for controlling the navigation of a robotic artifact, based on this principle. A prototype 'vestibular' interface has been developed to this purpose, based on a 3-axial artificial vestibular system, developed by part of the authors for humanoid robotics applications. Three different experimental sessions have been carried out by using: (1) a driving video-game; (2) a robotic endoscope, with a 2-DOF steering tip; and (3) a mobile robot with a camera on-board. The experiments showed that anticipatory head movements occur even when the person is driving a device, like those used in the experiments, and that such head movements always anticipate commands to the input device. The results indicate that the proposed hypothesis is valid and that a further research effort is worthwhile in the direction of using this novel principle to develop natural interfaces, which in fact can be very useful in many tasks, with different devices

Linking Small-scale Solar Wind Properties with Large-scale Coronal Source Regions through Joint Parker Solar Probe–Metis/Solar Orbiter Observations

International audienceAbstract The solar wind measured in situ by Parker Solar Probe in the very inner heliosphere is studied in combination with the remote-sensing observation of the coronal source region provided by the METIS coronagraph aboard Solar Orbiter. The coronal outflows observed near the ecliptic by Metis on 2021 January 17 at 16:30 UT, between 3.5 and 6.3 R ⊙ above the eastern solar limb, can be associated with the streams sampled by PSP at 0.11 and 0.26 au from the Sun, in two time intervals almost 5 days apart. The two plasma flows come from two distinct source regions, characterized by different magnetic field polarity and intensity at the coronal base. It follows that both the global and local properties of the two streams are different. Specifically, the solar wind emanating from the stronger magnetic field region has a lower bulk flux density, as expected, and is in a state of well-developed Alfvénic turbulence, with low intermittency. This is interpreted in terms of slab turbulence in the context of nearly incompressible magnetohydrodynamics. Conversely, the highly intermittent and poorly developed turbulent behavior of the solar wind from the weaker magnetic field region is presumably due to large magnetic deflections most likely attributed to the presence of switchbacks of interchange reconnection origin

Linking Small-scale Solar Wind Properties with Large-scale Coronal Source Regions through Joint Parker Solar Probe-Metis/Solar Orbiter Observations

The solar wind measured in situ by Parker Solar Probe in the very inner heliosphere is studied in combination with the remote-sensing observation of the coronal source region provided by the METIS coronagraph aboard Solar Orbiter. The coronal outflows observed near the ecliptic by Metis on 2021 January 17 at 16:30 UT, between 3.5 and 6.3 R ⊙ above the eastern solar limb, can be associated with the streams sampled by PSP at 0.11 and 0.26 au from the Sun, in two time intervals almost 5 days apart. The two plasma flows come from two distinct source regions, characterized by different magnetic field polarity and intensity at the coronal base. It follows that both the global and local properties of the two streams are different. Specifically, the solar wind emanating from the stronger magnetic field region has a lower bulk flux density, as expected, and is in a state of well-developed Alfvénic turbulence, with low intermittency. This is interpreted in terms of slab turbulence in the context of nearly incompressible magnetohydrodynamics. Conversely, the highly intermittent and poorly developed turbulent behavior of the solar wind from the weaker magnetic field region is presumably due to large magnetic deflections most likely attributed to the presence of switchbacks of interchange reconnection origin.</p