Neorocks final results - Romanian astronomers get involved

NEOROCKS stands for Near Earth Objects, Rapid Observations, Characterization and Key Responses.

NEOROCKS has connected expertise in performing small body astronomical observations and the related modelling needed to derive their dynamical and physical properties, to the pragmatic planetary defense approach, which aims to provide operational loops and information systems to protect citizens and ground infrastructures from potential threats. For more than three years the European consortium collected astronomical observations, modelled dynamically and physically surfaces and internal properties of Near Earth Objects (NEOs).

One of the objectives of NEOROCKS is to characterize as many Potential Hazardous Asteroids (PHAs) as possible in terms of their colors. NEOs have small diameters and can be observed from ground-based telescopes during close encounters with Earth. Their favorable geometries, sometimes for a time period of hours and days, need to be used to perform as many observations as possible in order to have access to several parameters that will ultimately aid in constraining their mass, shape, surface composition, surface rugosity, and internal structure.

The final results of the NEOROCKS color database are composed of 170 objects that were observed for more than 63 nights between 2020 and 2023. Most of these observations were carried out at the Observatoire de Haute Provence in France. A few observations were performed at the Pic du Midi Observatory (also in France). The survey was done in four broadband filters, namely B, V, R, and I. The sample also contains values of colors for asteroid (99942) Apophis, which will graze the Earth on April 13, 2029.

The statistics of the taxonomical types clearly indicate a large percentage of rocky silicate-rich asteroids (S-complex taxon). For objects with diameters smaller than 500 m, approximately 59% of them are S-type objects. This large percentage is mainly due to a bias induced by the surface reflectivity of objects (S-type asteroids are more reflective than C-type objects).

The chaos for the objects of the NEOROCKS color database was determined using the Lyapunov time of each object. The statistics show that the average Lyapunov time does not go beyond 100 years.

Several objects of the NEOROCKS color database have orbits similar to those of meteoroids associated with meteor showers. Among them, the asteroid 2011 OL51 was validated by two metrics used for this investigation, and it may be one of the parent bodies of the OCC meteor shower.

For more information on the subject follow the link here enclosed.
Birlan M., Barucci, M.A.,…, Sonka A.,…, Nedelcu A., …, Anghel S., et al - NEOROCKS color survey: Final results, Astronomy & Astrophysics, Volume 689, id.A334, 2024, https://www.aanda.org/articles/aa/pdf/2024/09/aa50495-24.pdf

Published on: Nov 01, 2024