NASA had hoped that asteroid Bennu would be smooth as a beach so their spacecraft Osiris-REX would have an easy time collecting a sample of fine space dust. Instead large rocks and boulders cover most of the 500 meter wide asteroid.
But NASA continues on with the mission nonetheless. Today the agency announced that they have selected the final four landing site candidates, designated Nightingale, Kingfisher, Osprey, and Sandpiper.
NASA has had to upload new software to Osiris-REX so that it can fly in with more precision than was originally anticipated in order to avoid crashing into rocks or sampling a spot where the grains aren’t fine enough – smaller than 2,5 centimeters – to go into the sampling collector.
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