Search

Abstract: We consider a network of telescopes capable of scanning all the observable sky each night and targeting Near-Earth objects (NEOs) in the size range of the Tunguska-like asteroids, from 160m down to 10m. We measure the performance of this telescope network in terms of the time needed to discover at least 50% of the impactors in the considered population with a warning time large enough to undertake proper mitigation actions. The warning times are described by a trimodal distribution and the telescope network has a 50% probability of discovering an impactor of the Tunguska class with at least one week of advance already in the first 10yr of operations of the survey. These results suggest that the studied survey would be a significant addition to the current NEO discovery efforts. [Copyright &y& Elsevier]

We propose an adaptation of the semilinear algorithm for the prediction of the impact corridor on ground of an Earth-impacting asteroid. The proposed algorithm provides an efficient tool, able to reliably predict the impact regions at fixed altitudes above ground with 5 orders of magnitudes less computations than Monte Carlo approaches. Efficiency is crucial when dealing with imminent impactors, which are characterised by high impact probabilities and impact times very close to the times of discovery. The case of 2008 TC3 is a remarkable example, but there are also recent cases of imminent impactors, 2018 LA and 2019 MO, for which the method has been successfully used. Moreover, its good performances make the tool suitable also for the analysis of the impact regions on ground of objects with a more distant impact time, even of the order of many years, as confirmed by the test performed with the first batch of observations of Apophis, giving the possibility of an impact 25 years after its discovery. [ABSTRACT FROM AUTHOR]

In this work we summarize the initial results of a targeted effort of the ESA NEO Coordination Centre to obtain additional observational data in order to eliminate or reduce the impact probability estimate of a subset of the known near-Earth objects representing the highest fraction of the total known impact risk, as measured by the Palermo Scale. [ABSTRACT FROM AUTHOR]