What Would Happen If an Asteroid Hit the Ocean?

What would happen if an asteroid hit the ocean? Seventy percent of this planet is water, which means any object falling out of the sky is overwhelmingly likely to land in the sea rather than on land. Most people find that reassuring, and it is one of the most dangerous misconceptions about impact events. The ocean does not absorb an impact. It converts it into something that travels, and then it delivers it to exactly the places we chose to build our cities. In this documentary we drop a three hundred meter asteroid into the open ocean and follow it second by second. You will see why water behaves more like a solid than a liquid at twenty kilometers per second, why the impact does not create a splash but a crater in the ocean itself several kilometers wide, and what happens when billions of tonnes of seawater collapse back into that hole and rebound. Then we correct the biggest myth in this entire subject. An asteroid impact does not send a single wall of water hundreds of meters tall sweeping across an entire ocean. Impact waves and earthquake tsunamis are not the same thing, and the reason why is genuinely more interesting than the myth. But that reassurance hides something worse, because roughly forty percent of humanity lives within a hundred kilometers of a coast, and shoaling means a wave that looks modest in deep water becomes something else entirely when it reaches a continental shelf. We then cover the two disasters nobody talks about: the enormous quantity of vaporized seawater injected into the upper atmosphere, and the collapse of a global supply chain built entirely around coastal ports. Finally we go back to the only large ocean impact in the record. Sixty-six million years ago an object ten to fifteen kilometers across struck a shallow sea near what is now the Yucatan Peninsula. The waves were not what killed the dinosaurs. The atmosphere was. And that single fact changes how we should assess the risk from any future impact. We finish with planetar