The Japanese space probe Hayabusa 2 has released an explosive-charge armed impactor called Small Carry-On Impactor (SCI) It was released at 0156 GMT on 5 April to deliberately explode on the asteroid 162173 Ryugu to carve out crater. Before the explosion, a small subsat called DCAM-3 – an imaging device to monitor events – was also released from Hayabusa 2 as the main spacecraft made a retreat to safety.
Update: DCAM 3 successfully imaged ejecta from the explosion