Carter, I don't think "fail safe" means what you think it means. That phrase doesn't apply in any way in this situation.
So by very little gravity, Carter means about 0.000001g. That is 1 millionth of Earth gravity. That is so little gravity picking your feet up would launch you into space when you try to out your foot back down. There is no walking, even with magnetic boots hoping to attract the iron in the rock. Iron ore in rock just isn't magnetic enough. And that rover, the first bump it hit would send if off into space.
Also, the notion that they can divert the asteroid with a 1 gigaton bomb is poorly thought out. Maybe if it was further out, but not a day before impact. That asteroid would be massive, about 1,000,000,000,000,000,000 kg. Even if all the energy of the blast was converted to kinetic energy of the asteroid, about 4,000,000,000,000,000,000 J, that would give the asteroid a lateral velocity of about 3 m/s. However, a more reasonable estimate is it will be less than 30% efficient (using the rocket nozzle analogy Carter mentions), so that leaves the asteroid with about 1 m/s lateral velocity, or about 3.6 km/hr. Over two full days, they will have diverted the asteroid by 173 km. So instead of hitting northern Greenland... nope still hits northern Greenland. Greenland is 2600 km long...
All around this was a craptastic scene/plan.
Oh, and as an aside, since they took the bomb into a cave, it will be less efficient at diverting the asteroid. Instead, it will be more likely to come apart so it can spread the love with impacts all over the northern hemisphere.
I do have to give some kudos. Even though we hear O'Neill and Teal'c walking when there is no atmosphere, someone was smart enough to have O'Neill put his hand on the escape pod to feel the vibrations of knocking, though I suspect between the metal and the gloves nothing would be felt. Kudos for the idea nonetheless.
Carter really is stupid. Who cares if the asteroid is denser than it should be. What are you going to do about it? It was fairly likely from the trajectory that this was a Goa'uld attack. Interesting that it is full of naquadah and you couldn't detect that before? Even if you weren't looking for it, the extra mass would have been obvious as it would be necessary for the trajectory to be what it is. Kinda how that works dumbass. Also, the fact that they are so close to the Earth they could set the atmosphere on fire with the enhanced explosion goes to show how ridiculously close the asteroid is to Earth and how stupid trying to divert it was.
Shout by LeftHandedGuitaristBlockedParent2021-03-10T22:12:37Z
A very enjoyable bottle episode, riffing on Armageddon but giving it a good Stargate twist. This really demonstrates how well the show straddled high stakes and humour without resorting to cheesy quips. The characters are just fun to watch work through things together.