There are many home-grown problems on Earth, but there’s still time to worry about bad things arriving from above. The most recent is the asteroid 2024 YR4, which could be a “city killer” if it hits a heavily populated area of our planet in the early years of the next decade.
The chances of that happening are now estimated to be around 0.001%. But there was a brief moment after the asteroid’s discovery last year when the estimated danger of a direct hit crossed the 1% threshold of comfortable risk.
