Periodic Reporting for period 2 - NEOShield-2 (Science and Technology for Near-Earth Object Impact Prevention)
Reporting period: 2016-04-01 to 2017-09-30
In contrast to other natural disasters, such as earthquakes and tsunamis, the impact of an asteroid discovered early enough can be predicted and prevented. Following on from the original NEOShield project (FP7), the objectives of NEOShield-2 included improvement of the targeting accuracy and relative velocity of a kinetic impactor spacecraft to deflect a small asteroid, and development of autonomous spacecraft control systems to facilitate navigation close to a low-gravity, irregularly shaped asteroid. Scientific objectives included astronomical observations of NEOs and the analysis of archival data (radar, infrared, spectroscopy, etc.), complemented by modelling and computer simulations, to improve our understanding of their physical properties and how a NEO would respond to a deflection attempt (for a more detailed Executive Summary see: http://neoshield.eu/n2es).
Astronomical observations [Fig. 7] of selected NEOs have been carried out for the purposes of broadening our knowledge of their mitigation-relevant physical properties, concentrating on the smaller sizes of most concern for mitigation purposes, and increasing the list of suitable candidate targets [Fig. 8 & 9] for deflection test missions. Statistical analyses of recently published NEO survey data have led to a novel means of estimating asteroid thermal inertia. Results suggest that the density and thermal conductivity of near-surface material increases rapidly with depth [Fig. 10], providing support for the kinetic impactor as a viable and effective deflection concept. Enhanced computer modelling and simulations in support of a NASA-ESA kinetic impactor study have provided insight into the post-impact ejecta evolution and fate [Fig. 11], which is crucial for the identification of safe locations for an observing spacecraft during and after a kinetic impactor deflection attempt.
Our study of the requirements for future research and international actions, in collaboration with the UN-mandated Space Mission Planning Advisory Group, has identified 11 areas requiring continued or increased effort at the present time. High on the priority list are the development and execution of deflection test missions on real asteroids and technologies for remotely-sensed physical characterization of small NEOs. Our results could form the basis of a European strategy for future mitigation-related endeavours.
Finally, the wider societal implications of our work lie in easing public concern over the impact hazard, and demonstrating that the scientific and space-engineering communities are abreast of the problem and have a good chance of successfully deflecting a dangerous NEO should one threaten the Earth in the near future.