This is more or less easy to see depending on the video you watch. Here's a good one that demonstrates it very clearly.

https://www.youtube.com/watch?v=ExV6PHRM8eI

I was impressed before. Now I'm doubly impressed after having watched that. Thanks.

This is even more mindblowing than landing on the fins. Amazing.

Landing on the grid fins would be a really bad idea. Even though they're car-sized, they're not load bearing and "only" made of steel (not titanium etc. .. just yet). Starship's Raptors blast during hot staging is enough to bend them on the top. https://www.reddit.com/r/SpaceXLounge/comments/1g3bi7s/grid_...

Though the original plan was indeed to land it on the (reinforced?) grid fins: https://x.com/elonmusk/status/1344327757916868608

I actually think there is some old Starbase tour interview where a SpaceX guy implied it was Musk's idea, though I could be misremembering. Catching the booster kind of makes sense, since they needed the tower arms anyway for stacking and unstacking.

They need to be able to handle some forces but indeed likely not an equivalent of half or even quarter of the booster landing weight.

Interesting, are there more than 4? because I was also amazed that the rocket was rotated at exactly the right angle to be caught by them. But maybe that is the 'easier' challenge when you are hovering with such accuracy.

I keep finding myself watching the catch every few days, and it does not tire to impress.