Deep Impact (1998)
A Comet discovered by a high school astronomy club (well, Elijah Wood) is coming to earth, only to be split in two by astronauts trying to destroy it. With the now two comets heading for Earth, it is revealed that there is sanctuary, but only those that have been selected. It’s a race against time to find higher ground, to be with loved ones and for astronauts to try again to save the world. Morgan Freeman plays a great US president.
Armageddon was out in 1998 too, pretty much the same plot, but has a lot more slow motion walking towards the camera.