Hey, it's Flora and you are listening to Science Friday.

When I think about dark matter, my mind goes to outer space. I imagine, I don't know, I imagine mysterious cosmic dust bunnies floating around in the distant universe.

But a lot of them, because we know dark matter makes up 80-something percent of the total matter of the universe.

But researchers are looking for signs of dark matter right here on Earth.

An experiment called Super CDMS is searching for the signatures of dark matter deep, deep underground.

Here to tell us more is Dr. Priscilla Cushman.

She's a physicist at the University of Minnesota and has been working on this dark matter

hunting experiment for over 20 years.

Priscilla, welcome to Science Friday.

Thank you for inviting me.

I love your show, by the way.

Oh, thank you. Appreciate it.

Also, welcome back to the surface of Earth. I understand you've been deep below for a bit.

I have. I have indeed.

Should I picture you in a lab coat and a miners helmet?

Well, the lab coat, no. You'll have to think more about a large miners coverall and a utility belt and a backpack filled with not only my own stuff I need, but also a self-rescuer that weighs about 20 pounds, marching about a kilometer to get to the lab, actually, at two kilometers below the surface. Wow. Why do you need to be so

deep underground to do this research? Well, basically, we have very, very sensitive detectors, right? And so

they're sensitive to everything. And that includes the cosmic rays, which are intersecting us and the

Earth at all times. And they get blocked by the Earth between the surface and where the lab is.

But the dark matter particles do not, because they are so weakly interacting, basically, they pass through the Earth.

You would count as many of them at night as at day because they can just

come through the other side of the earth anyway they will.

...