Regarding the Feb. 16 front-page article “Blindsided from space”:

The large asteroid that just passed by and its smaller companion that hit Russia say much about us. Decades after we realized that such asteroids can represent species-annihilating threats, we have prepared so little that all we can do when one of them moves close is to watch and hope.

The cost of being prepared is a tiny fraction of what we spend on almost any other threat. The dinosaurs had limited cognition. What is our excuse?

Norman A. Paradis, Putney, Vt.