Watched this in two halves. First half was quite good I thought, especially with respect to any science content (tho apparently the geography isn't so good) - no glaring physical impossibilities, plausible scenario. The inclusion of Ireland made the movie (refreshingly) not the usual completely US-centric fare. The movie's twist was that a comet strike/mass evacuation was the "best" option, not a nuclear strike - an interesting difference to Deep Impact / Armageddon.
It's in the 2nd half that things unraveled: 1. Even 4+ weeks before, it was _known_ that North America was the target( to give time for evacuation) - seems very unlikely given uncertainties in the comet's path and speed (I believe it's still relatively hard to predict where a decaying satellite orbit will impact) 2. The comet strike was powerful enough to decimate North Am but not cause a nuclear Winter by putting sufficient dust into the stratosphere - again improbable 3. Nukes could have been used to deflect the comet but would have required more than one attempt. Nukes can be as small as a kiloton (prob even less) so a small "calibration" standoff pre-strike could have been used to determine the likely effect of a bigger one, or cluster of smaller ones. Technically difficult but given the stakes..
The glare-prone/backlit look of the movie was also a turnoff.
But overall, certainly a lot better than most B-grade sci-fi.
6/10
It's in the 2nd half that things unraveled: 1. Even 4+ weeks before, it was _known_ that North America was the target( to give time for evacuation) - seems very unlikely given uncertainties in the comet's path and speed (I believe it's still relatively hard to predict where a decaying satellite orbit will impact) 2. The comet strike was powerful enough to decimate North Am but not cause a nuclear Winter by putting sufficient dust into the stratosphere - again improbable 3. Nukes could have been used to deflect the comet but would have required more than one attempt. Nukes can be as small as a kiloton (prob even less) so a small "calibration" standoff pre-strike could have been used to determine the likely effect of a bigger one, or cluster of smaller ones. Technically difficult but given the stakes..
The glare-prone/backlit look of the movie was also a turnoff.
But overall, certainly a lot better than most B-grade sci-fi.
6/10