Does the comet have enough gravity to hold on to dust?
Yes. Philae's weight on the comet is roughly equivalent to a few ounces/100g* on Earth. It's why there's so much concern about it not being anchored correctly; deploy the wrong instrument and you might push it away from the surface and out into space. So there is a significant gravitational attraction from the comet, just not very much!
* I've seen a few different estimates for this, but it's of this order.
Comments
Does the comet have enough gravity to hold on to dust? How do these small space objects even stay together?
Yes. Philae's weight on the comet is roughly equivalent to a few ounces/100g* on Earth. It's why there's so much concern about it not being anchored correctly; deploy the wrong instrument and you might push it away from the surface and out into space. So there is a significant gravitational attraction from the comet, just not very much!
* I've seen a few different estimates for this, but it's of this order.
Considering the comet's irregular shape, it probably depends a lot on exactly where the lander is.