[dr_lew]

(from a meter per second speed on impact of an object weighing a gram)?

The mass of the lander is given as 100 kg. At 10^-4 g that is 10 gram-mass units of "weight" on earth. In a constant g-field of this strength, the height of a 1 m/sec launch is 1/2 g t² = 1/2 v² / g = 500 meters . It should have rebounded less than this, as the landing was "damped", but I think the 1 km value was supposed to be a lateral distance, so it's of the right order.

[HandyDandy]

I borrowed the weight of the lander as being "one gram" while on the comet from post #23. I think I read somewhere that it weighs 1/32 of an ounce! Curiously the figure of .62miles was given for both the height of the bounce and the lateral distance that it landed from original touch-down spot.

I suppose that my suspicious theory that the harpoons actually did deploy, but into solid rock, probably would have sent Philae all the way back to Rosetta! (Especially in light of the downward thruster not working.)

[Swordmaker]

The mass of the lander is given as 100 kg. At 10-4 g that is 10 gram-mass units of "weight" on earth. In a constant g-field of this strength, the height of a 1 m/sec launch is 1/2 g t2 = 1/2 v2 / g = 500 meters . It should have rebounded less than this, as the landing was "damped", but I think the 1 km value was supposed to be a lateral distance, so it's of the right order.

I found a report that stated the gravity acceleration of 67P is only 1.5mm/sec^2. ESA publicly stated it "bounced 1km out into space and then 1km over," but that may be a wild, gassed guesstimate. . . or it was calculated from their knowing the approach velocity, the elasticity of the landing legs, mass of the lander and exactly what happened. I want to know why it bounced only once, since, according to reports the landing system—harpoon, thruster, ice screws, etc,—did not work at all.