Hi, you're about to get smarter in just a few minutes with Curiosity Daily from Curiosity.com.

I'm Cody Goff. And I'm Ashley Hamer.

Today you learn about why feet smell bad, how NASA knows where to dig on its next mission to find evidence of life on

Mars, and why you associate cold temperatures with luxury.

We're going from like feet smelling bad to luxury.

I love it. Good. Let's satisfy some curiosity.

Why do feet have such a specific pungent odor? I mean sure you keep them in your shoes

all day but your legs don't smell when you keep them in your shoes all day, but your legs don't smell when you keep them in your

pants all day, right? Well, that funky foot smell comes down to the type of sweat glands on your

feet and how many of them you have, plus a particular strain of bacteria, which happens to be the same kind of bacteria used in Limburger cheese.

Yum.

Most of the body's smells come from the armpits and the genitals, which are home to apocrine sweat glands.

The whole rest of the body, including your feet, is covered with echrin sweat glands.

Sweat itself is basically odorless and it's actually

bacteria on the skin that make our bodies smelly. That's why we shower. But the

sweat from apocrine glands has protein and amino acids in it. Those proteins and

amino acids feed the bacteria and that makes it stronger and, well, smellier.

Your feet are a little different.

Ekran gland sweat is watery and thin and evaporates quickly,

so it doesn't have time to get smelly.

The thing is, your feet have a lot of sweat glands. We're talking half a million sweat glands out of the

bodies two to five million. That's a huge proportion. In societies where people tend to go barefoot,

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