If you get asteroids about a kilometer in size, those are large enough and carry enough energy into our system to disrupt transportation, communication, the food chains, and that can be a really bad day on Earth.

When we see animals doing remarkable things, how do we know if we're simply seeing tricks or signs of real intelligence? Are talented animals just obeying commands, or do they have some kind of deeper understanding? One of the biggest challenges for animal researchers is to come up with tests that can distinguish between the two.

It's part of our pop culture to give animals human personalities and talents.

Neil deGrasse Tyson Quotes