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Hayabusa2 is scheduled to start its descent from 20,000 meters above Ryugu at around 1 p.m. Thursday, Japan time.
The probe is to continue to move down slowly and, at 500 meters above the surface, release a device called an impactor at around 11 a.m. Friday. The impactor is designed to explode 40 minutes later to fire a metal object into the asteroid’s surface at a speed of 7,200 kilometers per hour.
The original point of creating this crater was to allow visual access to the asteroid’s interior for geological study. Now it will also tell us exactly how cemented together this rubble pile is. The cobble might be held together tightly, or loosely. We shall see later this week.