My father was a very good Boy Scout. He was very skilled with knots, and he showed me how to tie a bow tie.

Science is the key to our future, and if you don't believe in science, then you're holding everybody back.

I've got no problem with anybody's religion. But if you go claiming the Earth is only 10,000 years old, that's just wrong.

Millennial voters are very concerned about climate change and will vote for candidates who are planning to address it. But the systems that are in place - people talk about gerrymandering and the money that's in politics, this is a real thing, a real effect - and it's hard for climate change-denying legislators to get voted out. But I predict it will happen.

When we see the shadow on our images, are we seeing the time 11 minutes ago on Mars? Or are we seeing the time on Mars as observed from Earth now? It's like time travel problems in science fiction. When is now; when was then?

Not wasting any water bottles is good. Not leaving the lights on is good. Turning the thermostat down in the winter, up in the summer, is good. But the best thing any of us in the developed world, especially in the United States, can be doing is talking about it.

We are just a speck, on a speck, orbiting a speck, in the corner of a speck, in the middle of nowhere.