AILSA CHANG, HOST:
What's something you wake up really early for...
DEAN REGAS: Get up a little early, just kind of kick back and relax.
CHANG: ...Which always feels like a big event...
REGAS: I feel like it's the day before Christmas or something, yeah, for me. I'm very anxious.
CHANG: ...And that you can watch from all over the world?
REGAS: I've had some pretty exotic ones in places like Hawaii and Greece, and then maybe less exotic ones, like parking lots and malls.
ELISSA NADWORNY, HOST:
Well, if you're astronomer Dean Regas from the Cincinnati Observatory, it's a total lunar eclipse. And if you look up late into the night tonight in North America and parts of Central and South America, you, too, will be able to share in the spectacle.
CHANG: And if you need a refresher on the celestial mechanics behind the phenomenon, a total lunar eclipse happens when the sun, Earth and moon precisely align, and the Earth's shadow slowly creeps across the lunar surface. With the naked eye, you'll be able to spot that transformation starting in the hours before the sun rises on Tuesday, around 4:09 a.m. Eastern time.
REGAS: And after about an hour, it plunges into darkness, where it turns all eerie shades of orange and red.
NADWORNY: That red color is why the total lunar eclipse is sometimes nicknamed a blood moon. And astronomer Laura Trouille of the Adler Planetarium in Chicago says there's a reason for that red color.
LAURA TROUILLE: It's the same thing that makes our sky blue and our sunsets red. The science behind it is just the Earth's atmosphere is scattering sunlight and scattering away the blue light and letting the red light through to light up the moon.
CHANG: Grab a pair of binoculars if you have them, but Trouille says you can also see the whole show with nothing but the naked eye.
TROUILLE: All you have to do is step outside and look up. And it's such a human thing to want to try to understand and be curious and wonder, how does this universe work? What's our place in it?
CHANG: And you won't want to miss it. The next total lunar eclipse won't be until March 14, 2025.
NADWORNY: So the question now is, are you going to set your alarm, or are you going to stay up all night? Trouille has her answer.
TROUILLE: Oh, you should stay up all night partying and celebrating the sky above.
CHANG: Sounds like a plan to me. Transcript provided by NPR, Copyright NPR.
