This project studies the physical and compositional properties of the so-called minor bodies of the Solar System, that includes asteroids, icy objects, and comets. Of special interest are the trans-neptunian objects (TNOs), including those considered the most distant objects detected so far (Extreme-TNOs or ETNOs); the comets and the comet-asteroid transitional objects (Centaurs and main belt comets or MBCs); the primitive asteroids. The last two groups contain the most primordial and pristine material of the Solar System and so they provide the clues to understand the origin and the subsequent evolution of our system. Among asteroid population, the near-Earth asteroids or NEAs, as well as the potentially hazardous asteroids (PHAs) are of particular interest: due to their proximity to the Earth, they are the most accesible to spacecraft and so are ideal for in-situ or even sample-return space missions. In addition they are considered as future potential resources of materials (asteroid mining), and they are also impact hazards for the Earth. Regarding primitive asteroids, it is remarkable the spectroscopic survey (visible and near-infrared) led by the PI of this project (PRIMitive Asteroids Spectroscopic Survey - PRIMASS). This survey received financial support from NASA (17-PDART17_2-0097, PI: N. Pinilla-Alonso, 137.000€ - 2 years) in order to upload and archive at the Small Bodies Node of the NASA Planetary Data System the more than 800 spectra obtained.

The compositional surface properties, as well as the physical and thermal properties of these objects are inferred through imaging, photometry, and spectroscopy in a wide range of wavelengths (from 0.35 up to 24 microns). Data are interpreted using scattering and thermo-physical models. This project works also in the study of the physical properties of the cometary nuclei, as well as properties of dust and coma in the tails of the MBCs and the mechanisms that generate them.

This group maintains several international collaborations with other groups, and some of their members are also members of (1) the Science Team of the NASA OSIRIS-REx mission, in particular the Image Processing Working Group, were they work with the images obtained with the OCAMS suite of cameras; (2) the coordination of an international group to study NEAs (EURONEAR); (3) the central core of the proponents of ESA M5 missions CASTALIA, CASTAway, and Hera; (4) the Center for Lunar and Asteroid Surface Science - CLASS (NASA); (5) the Solar System group of the Euclid consortium; (6) the surveys J-PLUS and J-PASS for the exploitation of observations of Solar System objects; (7) the Solar System working group of Gaia and JWST.