The investigation of near Earth Objects (NEOs)  can provide crucial  information on the formation and early evolution of the solar system and is also  important to constrain  the asteroidal contribution to the delivery of prebiotic material (water and  organic molecules) to our  planet (e.g., Pierazzo and Chyba, 1999; Morbidelli et al., 2000; Saladino et al.,  2013; OBrien et al.,  2014).

The reserve in water and rare metals held by NEOs is also gaining the  attention of government  agencies and private companies, as asteroid mining could expand the Earths  resource bases in the  near future (e.g., Sanchez and McInnes, 2013). Furthermore, NEOs represent a  well-known threat to  human beings and life in general: in particular, the “potentially  hazardous objects” (PHOs, i.e.  an object larger than 140m and orbital intersection distance less than 7.5  million km) could in  principle collide with the Earth within the next century causing extensive damage  (e.g., Perna et al., 2013,  2016).

The proximity of NEOs allows us to study  asteroids about two to three  orders of magnitude smaller than those observable in the main belt (i.e.,  down to metre-sized  objects), hence opening new frontiers in asteroidal science.

Small-sized (tens/hundreds of metres in diameter) NEOs deserve a special attention also in terms of hazard, as they have the highest statistical  likelihood of actually impacting the Earth, still producing catastrophic events  at a local/regional scale  (e.g., Perna et al., 2015a).

More in general, recent results already evidenced  that small asteroids  behave differently than the larger bodies in terms of rotational properties  (Statler et al., 2013) and  regolith generation (Delbo et al., 2014). However, such small asteroids become  bright enough to be  physically characterized from Earth only for very limited time spans,  coinciding with their close  approaches with our planet, whereupon they could become unobservable for  years or even for  decades.

Rapid-response physical observations of such bodies are hence necessary  in order to keep up  with the present trend of NEO discoveries toward small size objects thus  avoiding to leave the  characterization rate fall behind the discovery rate.