When Molly and I first met, we started talking about how she navigates the world, because I’m a nerd and I always steer the conversation toward science. I was not prepared for what she told me. She said she uses echolocation!
I went to NASA in Houston to talk to astronaut Don Pettit.
Why is ice slippery? It's a more complicated answer than it seems!
Recycling is broken. Here's how we can fix it.
