AILSA CHANG, HOST:
Forget world records because astronomers recently announced a new solar system record - the fastest spinning large asteroid ever discovered. It's about the length of eight football fields, but it fully rotates every two minutes - actually, a little faster than that. That and about 2,000 more new asteroids were identified from some of the first images captured by the brand-new Vera C. Rubin Observatory, home to the biggest digital camera on Earth - which prompts us to ask, if these are just the first images, what else do we expect to find? Well, here with more is Sarah Greenstreet, who led this study. She's an astronomer at the NSF NOIRlab and at the University of Washington. Welcome. Welcome.
SARAH GREENSTREET: Yeah. Thank you so much for having me.
CHANG: Well, thanks so much for being with us. OK, I first need to ask you, is this asteroid a threat to Earth? - this large spinning one.
GREENSTREET: It is not a threat to the Earth.
CHANG: (Laughter) OK. Good (laughter).
GREENSTREET: This is sitting hundreds of millions of miles away from us, nowhere near here.
CHANG: Good. I like that cushion. And why do you surmise that this giant space rock is spinning so quickly?
GREENSTREET: It's probably because it had some giant collision at some point in its past that caused it to spin at this extremely rapid speed.
CHANG: So interesting. I am struck, though, Sarah, that we're suddenly hearing about some fast-spinning large asteroids and all these other newly discovered asteroids. It feels like a lot of new asteroids in very little time, yeah?
GREENSTREET: Yes. Absolutely. Yeah. I still can't quite believe that we actually made this discovery, which was found in some of the very first test images. To put these numbers in context for how much discovery there's going to be with the Rubin Observatory, there are a couple of statistics that I find truly mind-blowing. And one of those is that we currently know of about 1 million asteroids and comets in our solar system, which have taken us the last 200 years to discover, which is the time we've been pointing our telescopes at the night sky. By the end of the first year of it surveying the night sky, the Rubin Observatory will double that number, discovering...
CHANG: Wow.
GREENSTREET: ...Another 1 million asteroids and comets in our solar system. And by the end of 10 years, as it's planned to be surveying the sky, it is going to discover a total of 5 million new asteroids in our solar system. We know there's a lot out there that are much smaller and farther away than we've ever been able to find before.
CHANG: So as someone who studies asteroids and comets very closely, can you just explain for people why is the study of asteroids so important to our understanding of the universe?
GREENSTREET: Yeah. So asteroids are important because they are essentially the leftover debris from when the planets formed 4 1/2 billion years ago. So they're the rocks that didn't become part of a planet while the planets were consuming the rest of the material near them through gravity as they grew to be the size that they are today. So that means that asteroids are essentially a time machine that allow us to learn what the very early solar system was like when the planets formed.
CHANG: So cool. Can I also just verify something I have written down here in my notes? There's an asteroid named after you. Is that true?
GREENSTREET: Yeah. Yes. There is. I...
CHANG: So it's the Greenstreet or the Sarah Greenstreet asteroid?
GREENSTREET: Yeah. It's 30535 Sarah Greenstreet...
CHANG: Oh, my God.
GREENSTREET: ...Is the name of my asteroid.
CHANG: What? Why is it your asteroid? How does this asteroid embody you, Sarah? Tell me.
GREENSTREET: Yeah. I still can't quite believe that I actually have an asteroid named after me.
CHANG: Oh, whatever. You say there's 5 million at least out there. How special could your asteroid be? I'm just kidding (laughter).
GREENSTREET: It's true. It's really not that much different than most of the asteroids out there. The solar system community in particular - we have a way to be able to nominate each other to get an asteroid named after you if you've made a significant contribution to the field of asteroid or solar system science. And so I am deeply honored to have had my former PhD adviser nominate me and then get chosen for an asteroid to be named after me.
CHANG: Sarah Greenstreet, astronomer at the NSF NOIRlab, and a scientist who has her own asteroid. Thank you so much for joining us.
GREENSTREET: Yeah. Thank you so much for having me. It was a pleasure.
(SOUNDBITE OF RAPSODY & HIT-BOY SONG, "ASTEROIDS") Transcript provided by NPR, Copyright NPR.
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