Jennifer Finnigan (Grace Barrows) and Jonathan Silverman (White House Counsel Roland Cavanaugh) are married off-screen.
Except for the railgun, all the solutions for the asteroid mitigation project, involve the principle of radiation pressure ( "painting the asteroid", or solar sails). That is, an indivisible particle of light, a photon, has the ability to push an object, and given a large enough surface area or large influx of photons this object can be pushed with minimal effort.
When Jillian and Nate are in the morgue, the body that the coroner is working on, is a real person. You can tell because you can see him breathe at one point!