Multiple communities are now interested in NEOs  for very different  reasons ranging from science to planetary  defence and commercial  objectives (e.g., mining).

Given the shared  scientific and  technological basis, all of these communities  require knowledge and  modelling capabilities of asteroid properties,  as well as the capability  to perform close proximity operations and make  relevant  measurements.

The multi-disciplinary approach  at the heart of NEO- MAPP, is perfectly suited for providing the  significant improvements  required in each of these aspects.

The most threatening NEOs - in terms of  collision frequency with the  Earth - are the smaller ones, i.e. below 1 km  in size. Yet, they are also  the population least known to us, as ground  observations cannot  provide adequate information at these sizes.  Space missions that are  currently visiting two NEOs, namely the JAXA  Hayabusa2 mission and  the NASA OSIRIS-REx mission, confirm that big  gaps still exist in our  knowledge, as they keep changing our  understanding of asteroids,  much like previous NEO missions (NASA NEAR- Shoemaker and JAXA  Hayabusa).

 These small bodies are very diverse  (Fig. 1), have very  complex histories and their low-gravity  environment challenges our  intuition. The limited number (4) of visited  NEOs with a rendezvous  mission already allowed us to obtain the first  direct measurements of  surface properties and, therefore, to go from  ‘zero knowledge’ about  these properties to a few crucial data points.  

Nevertheless, it remains  a challenge to extract from these space mission  data the relevant  information that allow us to determine and  model the main processes  that have shaped those asteroids, let alone  generalize to the whole  NEO population.