Neil deGrasse Tyson: We Live in a Cosmic Shooting Gallery

Astrophysicists have been telling people for decades, at least since the ‘80s, that Earth orbits the sun in a shooting gallery and asteroids hit Earth. They put life and civilization at risk. It was the 1980s where we finally concluded what was the primary reason that the dinosaurs were taken out of the tree of life: that an asteroid the size of Mount Everest slammed into what is today Mexico.

In fact, the Yucatán peninsula has a 100-mile diameter crater there that is left over from this impact. And we learned over the decades to follow that you didn't have to just be there to die; you can be on the other side of the Earth and still die from that explosion because that explosion alters the ecosystem. Fires that are triggered everywhere put soot into the atmosphere, blocking sunlight and knocking out the base of the photosynthetic food chain, and you can send a wave of extinction across the tree of life.

We’d begun to learn this in the 1980s. We’ve been telling this to officials, to elected officials, to government agencies. But it took an actual meteor over Russia exploding with 25 times the power of the atom bomb in Hiroshima to convince people that maybe we should start doing something about it.

I’m almost embarrassed for my species that you can be so blind to everything experts have been telling you, and you got to wait for people to almost die to say, “Oh, I guess they are out there. Let’s find legislation to help find them and deflect them.” So I’m a little embarrassed for us.

It reminds me of this comic... Forgive me, I forgot who wrote it. There are two dinosaurs talking to one another, and one says, “Now is the time to build an asteroid deflection system.” And the other one’s kind of leaning back, not paying much attention. Of course, they're gone; dinosaurs didn’t have a space program.

We’ve got a space program. We can do something about it if people have the foresight to understand what the risks are, the dangers, and actually act upon it. So yeah, fortunately, no one died in the Ural Mountains of Russia, but it’s still an expensive experiment. It was a shot across our bow...