Periodic Reporting for period 1 - NEOForCE (Near-Earth Object's Forcast of Collisional Events)
Période du rapport: 2022-11-01 au 2024-10-31
The modern world is subject to many natural, man-made and social dangers. Many of them are global in nature, as they threaten the very existence of human civilization. Notable among them is the danger of Earth collision with space bodies of cometary and asteroid nature. At present, there is no doubt about the importance and urgency of this problem. In particular, this is evidenced by a report of the National Science and Technology Council, USA, where the importance to detect and characterize the Near-Earth Objects (NOE) population and to prevent and respond to NEO impacts on Earth is outlined. To protect our planet from the dangers of collision with small bodies, it is first of all necessary to understand from which specific of almost 1 million bodies the Earth needs to be protected. The NEOForCE project aims to build a system to search for possible threats to the Earth from celestial bodies which is independent from the ones that are being operated at NASA and ESA, hence acting as an additional validation for risk assessment. NEOForCE has several objectives:
1) develop new methods for estimating of the impact probability of a small body with the Earth;
2) develop methods for obtaining more reliable estimates of orbital parameters and their uncertainties;
3) make a search for old observations of known objects.
Besides, several web-services at the LTE/Paris observatory have been developped with the aim to list:
1) potentially colliding with the Earth asteroids and comets with their impact probability values;
2) possible close encounters of asteroids and comets with the Earth;
3) old observations made on photographic plates many years, deacades, even centuries ago, with the identifications to the objects imaged on them.
1) develop new methods for estimating of the impact probability of a small body with the Earth;
2) develop methods for obtaining more reliable estimates of orbital parameters and their uncertainties;
3) make a search for old observations of known objects.
Besides, several web-services at the LTE/Paris observatory have been developped with the aim to list:
1) potentially colliding with the Earth asteroids and comets with their impact probability values;
2) possible close encounters of asteroids and comets with the Earth;
3) old observations made on photographic plates many years, deacades, even centuries ago, with the identifications to the objects imaged on them.
During the fellowship, we have developped an original and new semi-linear method for propagating orbits of Solar System Objects over time, together with their uncertainties, including the main planetary perturbations. It is an extension of the robust linear Partial Banana Mapping method. This enables us to compute close encounters of Near Earth Objects with the Earth (and terrestiral planets in general). In addition to orbit & uncertainty propagation, we have also developed a comprehensive scheme for impact probability estimation. In the new approach explicit initial conditions in the orbital space that lead to a collision are determined. This leads to analysing the variance/covariance matrix and its line-of-variation to derive virtual impactors, and compute any asteroid's impact probability (IP). Additionally, we have initiated a work for precovery (or recovery) of asteroids, and applied the methodology to some ancient photographic plates at Paris observatory.
All results were validated by benchmarking with other ephemerides centres prediction and tables, and with reference additional high fidelity Monte Carlo simulaitons.
This new methoodology is implemented in a software suite and workflow at Paris Observatory for publishing online orbital databases and ephemerides of NEOs.
In addition, this work and scientific results have been published in peer-reviewed journals, and presented in international conferences.
All results were validated by benchmarking with other ephemerides centres prediction and tables, and with reference additional high fidelity Monte Carlo simulaitons.
This new methoodology is implemented in a software suite and workflow at Paris Observatory for publishing online orbital databases and ephemerides of NEOs.
In addition, this work and scientific results have been published in peer-reviewed journals, and presented in international conferences.
The project has been successful, with various outsomes. Based on the Partial Banana Mapping — which uses a specific set of coordinates describing the orbit — one can propagate an orbit and its variance/covaiance matrix over long period of time, with the advantage of being faster than a full Monte Carlo method, and more precise than a simple linear approximation.
The methodology thus shows some practical advantages that are of interest in the scheme of large surveys providing many detections of Near Earth Objects, such as the future VRT/LSST. It also provides detailed ephemerides of close encoiunters with the Earth, including some prediction reliability. Moreover, when considering asteroid threatening of impacting the Earth in the next Century, it is mandatory to properly assess the risk and impact probability (IP) by comparing different independant methodologies. Besides, the scheme is applied to data-mining of ancient observations made decades or century ago in order to perform precovery of NEOs and PHAs. It has been applied to pre-covery of NEOs on ancient photographic plates, that can be far from the nominal orbit predicted position. Such observations are again of high value to orbit and IP computations, and the methodology increases the efficiency of such data mining.
The work is implemented in webservices and publicly available tools for NEO predictions.
The methodology thus shows some practical advantages that are of interest in the scheme of large surveys providing many detections of Near Earth Objects, such as the future VRT/LSST. It also provides detailed ephemerides of close encoiunters with the Earth, including some prediction reliability. Moreover, when considering asteroid threatening of impacting the Earth in the next Century, it is mandatory to properly assess the risk and impact probability (IP) by comparing different independant methodologies. Besides, the scheme is applied to data-mining of ancient observations made decades or century ago in order to perform precovery of NEOs and PHAs. It has been applied to pre-covery of NEOs on ancient photographic plates, that can be far from the nominal orbit predicted position. Such observations are again of high value to orbit and IP computations, and the methodology increases the efficiency of such data mining.
The work is implemented in webservices and publicly available tools for NEO predictions.