It is the nightmare that launched a thousand disaster movies: What if a giant object from outer space, like an asteroid or comet, smashed into Earth and caused an extinction-level event?
Whenever a celestial contender emerges from the cosmos, humanity pays attention, as happened when an asteroid approached Earth during the 2020 election season (it was never a threat) or when one large enough to wipe out a country just missed us (that happened in March last year). Now an asteroid that is four times longer in diameter than the Empire State Building is approaching our planet. If it struck, calamity would ensue.
