Hayabusa-2s Mascot probe landed on Ryugu earlier this month to more closely observe the asteroids surface. They’ve learnt that Ryugu is extremely rocky, uneven and full of large boulders that will make it difficult for Hayabusa-2, the larger mothership, to secure a proper landing zone in late October. So instead the launch has been delayed by 3 months to January.
What was even more surprising is that given all the rocks and boulders on Ryugus uneven surface, there appears to be absolutely no finer dust.
“In fact, it is even crazier on the surface than expected. Everything is covered in rough blocks and strewn with boulders. How compact these blocks are and what they are composed of, we still do not know. But what was most surprising was that large accumulations of fine material are nowhere to be found – and we did not expect that. We have to investigate this in the next few weeks, because the cosmic weathering would actually have had to produce fine material,”