I would guess that a rock measuring 1 kilometer across, landing near New Zealand 500 years ago, would have done much more than create a tsunami 300 to 500 feet high. Was the object 1 km across before encountering Earth’s atmosphere?

Don Arthur
North Coventry, Pa.

Yes. The object’s estimated size is before it hit the atmosphere. The damage it inflicted is indicated by the large crater it left on the ocean floor .—S. Perkins