sentences:  The first sample collection was scheduled to start in late October 2018, but the rovers encountered a landscape with large and small boulders but no regolith to sample, so the mission team decided to postpone the sample acquisition to 2019 and evaluated several options.Its first surface sample retrieval took place on 21 February 2019.On 5 April 2019, "Hayabusa2" released an impactor and created an artificial crater on the asteroid surface.