The primitive small bodies: from the origin of the solar system to the origin of life

The so-called “primitive” small bodies (carbonaceous asteroids, centaurs, comets, trans-Neptunian objects) have formed in the water- and organic-rich outer regions of the protoplanetary disk. They carry information on a number of evolutionary processes which have taken place since the solar system formation, and, in particular, they are considered as the most probable source of terrestrial prebiotic material.
In this talk, I will present the results of a 30-night observing programme carried out at the ESO-NTT in 2015-2017, the first-ever spectroscopic survey dedicated to the “small” (up to a few hundred meters) near-Earth asteroids (NEAs). Noteworthy, smaller asteroids could deposit prebiotic material on the early Earth in a more efficient way, without massive water vaporization and destruction of organic molecules as in the case of larger impacts.
I will also discuss about the ongoing sample return missions from primitive NEAs Ryugu and Bennu, that will be reached in 2018 by the Hayabusa 2 (JAXA) and OSIRIS-REx (NASA) spacecrafts, respectively. Such missions will be fundamental to assess if the organic compounds contained in primitive asteroids can indeed be associated with the formation of life on Earth.
Finally, I will report about a long-term observational programme aimed to investigate the composition and cometary activity of centaurs, a transitional population between the trans-Neptunian regions and the inner solar system. It is to be reminded that the impact of Centaur-like objects might have significantly contributed to the delivery of noble gases and amino-acids to the early Earth.