Based on truly possible events.
Why it is hard sci-fi
A planet-killer comet is on a six-month trajectory to Earth. The film is a satire of how a society organised around media incentives and political opportunism would fail to act. The science is the easiest part. The astronomers do their job. The film follows the policy, communications, and corporate interests that sequentially fail. The premise is a controlled experiment in institutional response.
Science inside it
Orbital mechanics, near-Earth-object detection, kinetic deflection mission profiles, and the institutional decision-making chain that runs from observation to launch authorisation. The films second-half pivot, where a billionaire intervenes to mine the comet for rare earth elements, is the films sharpest engineering point. A profit motive defeats a deflection plan.
Spoiler alert
The mining mission fails because the comet is too large to be split safely and the deflection window is missed. A small group of billionaires escape on a sleeper ship to a habitable exoplanet and emerge twenty thousand years later into an environment that immediately kills them. The film commits to the joke.