Short Wave - A Newly-Discovered Asteroid And What's Beneath The Ice On Enceladus

Episode Date: June 16, 2023

All Things Considered host Ari Shapiro returns to nerd-our with Short Wave hosts Emily Kwong and Regina G. Barber on three science headlines from space: a newly-discovered asteroid, a new moon-related discovery and a new study about what spaceflight does to the human body. Have questions about science in the news? Email us at [e-mail] pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, Short Wavers, Regina Barber here with Emily Kwong. And an interloper, Ari Shapiro. A friendly alien from a distant show. Ari returns to nerd out and help us wrap up the week with our science news roundup. Yeah, Ari, what do you say we take a break from Earth for a bit? I honestly find space really scary, but I trust you to keep me safe and take me where we're going. I welcome the honesty. This week, we've got three stories that take us to space.

We're going to check out a new asteroid discovery, talk about a recent finding on a distant moon, and deepen our understanding of what spaceflight does to the human brain. Well, I'm ready for a liftoff, and maybe we'll discover for ourselves what spaceflight does to our brains. Let's do it. You're listening to Shortwave from NPR. As usual, Ari, you're here to learn about three science stories in the news lately, one about an asteroid and one about space. Spaceflight and the human brain. Tough choice. But let's start with the human brain. Okay. This first story is how spaceflight affects the brain.

And it's a big topic of interest. Because if you think about it, commercial spaceflight is totally on the rise, right? And it's not just like these short hops where people float around without gravity for a few minutes. They're actually visiting the International Space Station. Yes. The future of spaceflight is looking expansive. We know what long-term spaceflight does to the body. There's the increased radiation, the social isolation, the weakening of your muscles and bones from the microgravity. But it turns out that spaceflight also changes your brain.

Rachel Seidler studies this at the University of Florida. In the absence of gravity, the brain is actually sitting higher in the skull, and the top of the brain is a little bit compressed against the skull. There's also headward fluid shifts that happen in the absence of gravity. gray matter shifts. The cerebral spinal fluid in your body moves around too. A lot of first-time astronauts are a report fluid buildup in the face, what they call puffy head bird legs. And we don't know how this affects someone's health long term.

Rachel made me think about how this issue is colliding with our very evolution. Yeah, because we evolved with gravity. Emily, you're not making space any less scary for me right now. Yeah, I mean, we got to deal with the facts in front of us. You know, our bodies were designed for fluid to travel up. and without gravity, there's nothing to pull it down. So Rachel's study published in scientific reports last week looked at 30 astronauts. Those in space for two weeks saw minimal brain changes.

But at six months, their brains saw a lot more changes. And astronauts who went for a year or more, there was no further change, kind of like a plateau, suggesting the brain was trying to adapt to space. And after people come back to Earth, did the brain changes reverse? Not really. At least not for a long time. One of the most typical things researchers see among astronauts post-flight is these cavities called ventricles deep in our brains expanding. They're trying to accommodate all of that fluid shift from living in a weightless environment.

And interestingly enough, the earthbound astronauts whose last spaceflight was less than three years ago demonstrated less adaptation to all that fluid, less expansion in their brains. And that actually worries Rachel, because if these pockets of the brain aren't expanding to take up all that fluid, the brain itself may be getting compressed. We're not totally sure of the health risks of any of this. But she worries that the potential pressure on the brain from too little time back on Earth might not be a good thing. So what's the solution apart from just don't go to space? Or spending more time on Earth between space flights to allow the body to kind of recalibrate. I mean, this is the kind of research and data we need, right, to figure out what to do. It's a new area of study spaceflight in the brain.

It only began less than a decade ago. And if we're going to go to space, which we clearly want to do, work like this could help inform... Speak for yourself. Fair. Some private citizens and a lot of space companies want to do. Work like this could help inform more thoughtful policies about what would be healthy when it comes to the humans spending time in space. Okay. Our second space story comes from you, Regina.

And this is about water on one of Saturn's moons? paint a picture for us. Yeah, I actually love the icy moons in our solar system. It's one of the reasons I got into astronomy. And also, a few of those icy moons show evidence of possible oceans underneath, like Enceladus that orbits Saturn. An ocean on Enceladus. Why do scientists think there's water there in the first place? Yeah, there is this really cool mission called the Cassini mission, and it flew by Enceladus numerous times, like between 2004 and 2017.

And it collected data from a plume shooting liquid into space. from Enceladus's surface. It was recently analyzed and it was published in the journal Nature, and the researchers detected amounts of phosphorus at higher levels than our oceans on Earth. And phosphorus may sound familiar. It's a macronutrient that makes pools become overrun with algae, right? You're totally right, M. It's a basic ingredient in fertilizer. Look, I'm a gardener. Water plus fertilizer equals plant growth. Does that mean anything is growing on this moon of Saturn? I mean, we always need to be careful when talking about life on other worlds, but phosphates in water can point to possible, possible habitability in an ocean that

most likely exists under that ice. And I talked to a planetary geochemist, Mikhail Zolatov, at Arizona State University, and he was not associated with the study. But he says it's a positive sign. If there is life there, they wouldn't have to struggle like ocean organisms do in our oceans that don't have enough phosphorus. Okay, I'm really into this. How are they going to find out if there is actually life on this moon of Saturn? Yeah, that's for future missions. Ones that look at these icy moons. There's one actually in the works that's called Jupiter icy moon explorer or juice. But yeah, as for Enceladus, I mean, we can't rule it out, right? So that's pretty fun. Totally. Okay. Third and final space story is about a newly discovered asteroid. Tell me it's not

hurtling towards Earth. No, it's not too close. So we tend to think of asteroids as like these random objects hurling like throughout space, throughout the solar system. But they actually have very predictable flight patterns. Many have these large orbits. around the sun, and scientists recently detected one, and it's called 2023 FW13. It's orbiting the sun along a path very similar to Earth's orbit. And that's what's unofficially known as a quasi-moon. As in, like, our Earth has a moon and also a quasi-moon? Yes, yes, but we shouldn't go thinking we have two moons.

This asteroid, it's not orbiting Earth. It's only slightly influenced by our planet's gravitational pull. So it's more like a fellow passenger driving a similar highway as us as we lap around the sun. And it's much smaller than our moon. It's the size of a camper van, like a quasi-moon Winnebago. Quasim moons like this one have been discovered before, and they tend to come and go. And this one might be one of the oldest quasimoons ever found. Like some estimate it's been circling the sun since 100 BC and will likely do that until 3,700 AD.

And at that point, its orbit will kind of break down and it'll be. probably like just amble off to wherever its velocity takes it. Amazing to me that astronomers can not only detect this thing, but figure out its age. Okay, so if it does wander off at some point, could it potentially be dangerous to, you know, those of us on Earth? No. So the quasi-mood's orbit doesn't come close to Earth at all. Plus, its orbit is so stable that we'd probably know about any dangers like decades in advance.

That's what one astronomer told side telescope magazine, which reported on this discovery. Yeah, that article mentioned to Ari, how we... One of the most remarkable things about this quasi-moon was that it was even discovered at all. It was a total accident. Scientists weren't looking for it. They just noticed it. And it took data from multiple observations in Hawaii and Arizona to confirm the finding. But it's all just a reminder that space is a big place.

We know only a fraction of a fraction of what's going on out there. Hopefully this makes you understand it a little better, though. Yeah, I mean, in a space that big, it's easy to miss a quasi-moon the size of a Winnebago. Thanks again to Ari Shapiro for dropping by. As always, if you see a science headline you'd like us to explain in the roundup, tell us about it. Email us at shortwave at npr.org. This episode was produced by Burley McCoy and Gus Contreras. It was edited by Brent Bachman and Christopher Inteliata, Britt Hansen checked the facts, Neil Tevall and Robert Rodriguez for the audio engineers.

Our senior director of programming is Beth Donovan and our senior vice president of programming is Anya Grenman. I'm Emily Kwong and I'm Regina Barber. Thanks for listening to Shortwave from NPR.