why doesn't Hayabusa or other comet SRM's count as a comet landing

[xenomorph555]

People keep saying "ROSETTA IS FIRST TO LAND" but never mention hayabusa

[Kryten]

Because Hayabusa landed on an asteroid.

[Will Fawkes]

That is an excellent point.

[Fuzzy Dunlop]

Also Hayabusa wasn't the first asteroid lander (though it was the first, and at the moment only, to return samples from the surface). NEAR Shoemaker landed on 433 Eros in 2001.

It's worth noting that as well as being much further away comet 67P/Churyumov–Gerasimenko is about 300 times more massive than Hayabusa's target 25143 Itokawa (though Eros is about 600 larger than the comet).

[Camacha]

I think those encounters are respectively counted as a bump and a slow crash, rather than a true landing. This one has been precarious too, but seems to be a landing. Or three, depending on how you look at things.

[Guest]

When it comes to objects like this, what all of those probes did resemble docking more than actual landing. The gravity is just that weak. You could get a feel of it by trying to land on Gilly or Bop in KSP.

It isn't exactly exciting, from a technical standpoint, that we managed a landing on such an object. Nevertheless, it's the first time we got this close and personal with a comet (impactors don't count, since they can't transmit after being expanded). That's very interesting from a scientific point of view, comets are very different animals from asteroids.

[Camacha]

It isn't exactly exciting, from a technical standpoint, that we managed a landing on such an object.

I feel it is. Someone likened it to throwing a frog on a parachute from a plane and successfully landing it on a football kicked across the yard. I feel that is - from a technological point of view - pretty accurate, though they omit the part where you do all this from a couple of cities away. Sure, we did not just try to do this without other previous experiences, it is the result of decades building up to it, but it is still mighty impressive. Even without the science you can call it a huge triumph.

[metaphor]

It isn't exactly exciting, from a technical standpoint, that we managed a landing on such an object.

From a technical standpoint, the hard part was getting into orbit around a comet, which Rosetta was the first spacecraft to do.

[problemecium]

^ This. The tough part isn't bumping into it. It was managing to rendezvous with something in a highly eccentric orbit, getting close without being obliterated by high-speed sand grains and pebbles, and attaching to it without slipping off due to unstable "terrain".