Largest M-type asteroid encountered by a spacecraft

Largest M-type asteroid encountered by a spacecraft
Who
21 Lutetia
What
121 kilometre(s)
Where
Not Applicable
When
10 July 2010

On 10 July 2010, the Rosetta spacecraft flew by asteroid 21 Lutetia at a minimum distance of 3,168 km and a relative velocity of 15 km per second. Lutetia is an M-type asteroid with a high metal content in the main asteroid belt measuring 121 x 101 x 75 km and was the largest asteroid overall encountered by a spacecraft until NASA’s Dawn mission entered orbit around 4 Vesta on 16 July 2011.

This record will be surpassed by the NASA Psyche probe, which is scheduled to rendezvous with the asteroid of the same name in 2026. It is scheduled to launch in August 2022.