It's impossible to know the exact speed of the Chicxulub asteroid (the one that impacted the Yucatan Peninsula) with absolute certainty. However, scientists have estimated its speed based on various factors like the size of the crater, the ejected material, and the nature of the impact.

Here's what we know:

* Estimates: Scientists generally believe the Chicxulub asteroid impacted Earth at a speed between 11-72 km/s (25,000-160,000 mph).

* Impact angle: The impact angle also plays a role in the speed. A shallower angle would lead to a longer, more drawn-out impact, while a steeper angle would result in a more explosive event.

* Uncertainty: While the estimates provide a general idea, the actual speed remains uncertain. There's still much we don't know about the asteroid's composition, trajectory, and its precise interaction with Earth's atmosphere.

It's important to remember that even at the lower end of the estimated speed, this asteroid was traveling incredibly fast. The impact was catastrophic, leading to the extinction of the dinosaurs and a major upheaval in Earth's ecosystem.