NASA's Double Asteroid Redirection Test (DART) spacecraft hurtled toward a binary asteroid while it was 11 million kilometres from Earth at a speed of 22.530 km/h. The spacecraft was equipped with a state-of-the-art imaging system that worked together with a state-of-the-art onboard set of targeting, guidance, navigation and control algorithms. The huge technological challenge of colliding with an asteroid at hypervelocity was achieved with success on September 22, 2022. All together, this NASA mission autonomously identified and distinguished between the two asteroids in its final moments, finally targeting the smaller body called Dimorphos, obtaining valuable science and finally crashing into it. As a consequence, DART impact shortened the orbital period of Dimorphos within the binary system in 33 minutes, a big success for the application of the kinetic impactor technique to planetary defence.

The success of the DART mission started a new age of planetary defence. This new area of planetary science is associated with the study of minor bodies: asteroids and comets. In a context of applied science, space exploration needs facts: we need to know the real physico-chemical properties of all the objects surrounding the Sun. Asteroids and comets have several properties that make them very different from planetary bodies. Then, planetary defence tries to develop our capabilities to study these bodies and to detect, and mitigate the risk from potential asteroid or comet impacts with Earth. In some sense, planetary defence can be considered "applied planetary science", a new discipline to address any future risk of impact by Near Earth Objects (NEOs).