Short Wave - Solutions Week: The Cost Of Food Delivery

Episode Date: September 10, 2024

Since the height of the pandemic, there has been a boom in the use of food delivery services. Day 2 of NPR's Climate Solutions Week is all about the environmental impacts of how we shop for our food. So in this episode, NPR correspondent Scott Neuman reports on a question we've all wanted to know the answer to: What is the impact of getting food delivered on our carbon footprint?Interested in hearing more climate solutions? Email us at [e-mail] – we'd love to hear your ideas!See 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 Barbara here with a look at NASA's mission to my absolute favorite moon in the solar system, Europa. It's one of Jupiter's moons. So Europa is mostly made of ice on its surface. So it's actually very reflective. It's mostly sort of white. That's astrobiologist and friend of the show, Mike Wong. But if you zoom in, there are these red streaks, these cracks on its icy surface.

where it seems like it's been contaminated with some kind of material, like reddish or dirty brown or something like that. We think that some of the material from inside Europa's ocean has come up to the surface at these cracks and then has been bombarded by radiation from Jupiter's magnetosphere. And that radiation then turns that material into this kind of reddish, brownish color. We talked to Mike about the Europa Clipper Mission, which launched Monday. Three, two, one, ignition.

And lift off. List off. It won't get to Jupiter until spring of 2030. After that, we'll know whether Clipper achieved his goals to understand more about this moon. Its structure, how thick its ocean is, and the big one, to figure out whether it could sustain life. It's for that reason, the possibility that there could be some form of life on Europa, that Mike is obsessed with the moon and this mission. It's also why he loves two of Saturn's moons, Enceladus and Titan.

Oh my gosh, don't make me rank them. Okay, because it's like a three-way tie between Europa and Celadus and Titan. As an astrobiologist, those are the three that you look to as great places to try to search for life beyond Earth. Mike says all three of these places have the trifecta of ingredients needed to sustain life, liquid water, specific elements, and an energy source. So why Europa instead of these other two moons? On Europa specifically, we think that its subterranean ocean holds at least twice as much water as all of Earth's oceans combined. And so, you know, it's a tiny moon, roughly the same size as Earth's moon, which is bone dry. But it's got twice as much water, if not more, hiding underneath its icy crust as all of Earth's oceans combined.

When I first heard that, that blew my mind. And I was like, okay, let's go looking for life there. Today on the show, The Hunt for Life on Europa. Plus, we look at voyages to icy moons in the past, like the Cassini mission, and what this Europa Clipper mission might tell us about life as we know it. I'm Regina Barber, and you're listening to Shortwave, the science podcast from NPR. Okay, so, Mike, we have these, like hints about what Europa is like, But what do we actually scientifically know about this moon?

Yeah, we're pretty sure that Europa has a global liquid water ocean that is somewhat salty. This is because of the way that Europa responds to Jupiter's magnetic field. So it would take a salty ocean with these salt ions in it to basically change the local magnetic fields around the moon. And this was sensed by the Galileo spacecraft, which visited Jupiter in. and swung by Europa, and was able to use its magnetometer, the thing that measures the magnetic field, to sense that there was something bizarre happening when it flew by Europa. And after scientists did a bunch of physics, right? This is hard.

Yeah. It was like, oh, okay, the only thing that could really explain this kind of magnetic anomaly was if there was something conducting electricity inside of Europe. And what? Yeah. And so the only plausible explanation was that what if there was a salty ocean beneath that ice crust? And, you know, the more we learned about Europa, the more evidence that we gathered that sort of like corroborates this idea that, yeah, because Europa is an orbital resonance with several of the other moons in the Jovian system. It's just getting pulled by all these other moons. Exactly.

And that friction of being pulled and squashed mostly by Jupiter's gravity as it orbits in its sort of oval. shaped orbit, that would supply the heat, the thermal energy required to keep Europa's ocean liquid instead of just freezing up at those distant, frigid temperatures, you know, 25 times less sunlight out at Europa than here at Earth. So this isn't the first trip that we've put out there, like, to learn more about these icy moons in our solar system. There's also the Cassini mission that collected data around Saturn, starting in like 2004. Why was that? mission such a big deal? So the Cassini mission was this flagship mission that was sort of a jack of all

trades, explore the Saturn system in all its glory. And the Saturn system has a lot to offer. I mean, there's Saturn itself, which is a beautiful gas giant planet. It's got its amazing ring system. And then dozens of moons that are all intrinsically valuable and worth exploring, two of which could potentially host life. That's Enceladus and Titan. And so, we learned from the Cassini mission that the icy ocean world Enceladus, which is kind of like a mini version of Europa, also has a global liquid water ocean and has the kind of chemistry that results from hydrothermal systems, which are a leading geochemical environment for the origin of life. And we suspect that similar hydrothermal conditions would exist at the bottom of

Europa's ocean as well. Yeah, I mean, scientists, like, they don't know for sure if they're hydrothermal vents there, but the Cassini mission, it got water shot at it by Enceladus. That's also a reason why this mission was such a big deal. Yeah, so Enceladus does this brilliant thing that it just sprays part of its ocean into space all the time. It's got these perennial geysers shooting out of its south pole, and the geyser material originates in Enceladus's liquid water ocean. So by flying through this geyser and sampling the chemistry of the particles that have emerged from the geyser, you actually get to sample something that came from its liquid water ocean.

Enceladus is just constantly pouring its guts out for us to sample, and luckily the Cassini orbiter was there to actually taste that and get to know the chemistry of the ocean. Europa is a bit more cagey. But the Cassini data from these water samples weren't definitive. Like, we don't know for sure if there's life in that ocean, but there are building blocks for life, which is fascinating. That's a whole other episode. Yeah. And Cassini, it's not around anymore because, like, in 2017, it was sent into Saturn's, like, atmosphere to burn up.

Yes. Because NASA, in the event, any of these moons did have, like, the tiniest inkling of life. They didn't want that spacecraft with, like, possible microbes on it from Earth to accidentally contaminate, like, any other place. Exactly. Right. there might be tiny microbes that despite scientists' best abilities of, you know, scrubbing these instruments clean, still hitched a ride to the outer solar system. And if one of those microbes, and we know microbes are really hardy creatures, they can go

into these protective spore-like stages of their life cycle and just hang out in really harsh environments and then reanimate themselves when they get a more habitable condition, you know, you crash land on one of these habitable moons, and then you, you, you start to infect it basically like an infection from Earth. And that's not what we want. So, okay, so, you know, we've to talk to it a little bit about history of these Saturn moons. Let's go back to Jupiter's moon, Europa, where we started here. Like you said the Clipper is going to fly by.

Why not land on Europa? Yeah. So Europa is constantly being pummeled by the radiation in Jupiter's magnetosphere. And so a lander or even an orbiter around Europa wouldn't last very long. Its instruments would be fried. And that's why Europa Clipper has this super wide, elongated orbit, where it actually orbits Jupiter and makes these flybys of Europa. But, you know, one thing that people maybe forget about is that the radiation on Europa,

despite it being very dangerous to our spacecraft, might be the key to why Europa is habitable, or at least one of the keys. So all life as we know it basically needs to eat and it needs to eat, and it needs to breathe. So we eat food and we breathe oxygen. But, you know, there's many different ways of making a living. Certain microbes like literally eat and breathe rock, right? So you can even breathe whatever you want.

There just needs to be things to eat and breathe. On Europa, where would the breath that sort of oxygen come from? We think it comes from the fact that its icy surface is constantly being slammed by these energetic particles. And when you break apart water, you know, you break apart H2O, you get hydrogen, you get oxygen. The hydrogen is super light, so it escapes off into space and the oxygen is left behind. And so Europa's surface might be coated in basically oxygen that is created by this radiation. And if that oxygen is then able to get into the ocean, that could supply the ocean with the oxygen needed for Europen life to breathe. Okay, okay. So will there be any inkling of life on Europa that like anyone in the astrobiology community can call like life?

I get asked this question all the time. And I always have to clarify, is the question, is their life on Europa? Or is the question, is their life on Europa and we will find it? My question is, is there life on Europa? I think that there's a really good chance that there could be life on Europa. And if there's not, it will also teach us something really fundamental because it means that something wasn't quite right on Europa to either originate or to sustain life over billions of years. So why do you think the Europa Clipper, like you were talking about earlier, that it's debatable that the Europa Clipper mission can actually like definitively tell us that there's life on Europa? Like, why is that? Yeah, because a different kind of mission architecture, what people are calling a Europa lander, which actually does brave that radiation, go onto the surface of Europa and sort of maybe, you know, rove around the surface or taste the surface or maybe even melt or drill through the ice and try to get to the ocean, that would give us data that could be really definitive about life on Europa. But because this thing is staying in space, for the most part, staying very far away from Europa and making these quick dashes by Europa, it's going to give us a lot of new information about the structure, the interior, and the potential habitability of Europa, but may not give us the kind of data we need to definitively save there's life.

I think one of the biggest open questions in science is, are we alone in the universe? And we want to know, is life just a random occurrence that happened to, you know, we got lucky, essentially, or does it occur wherever the conditions are right? And in our solar system, you know, I don't think there is a place more tantalizing than Europa as a second harbor for life. And I think it's also a monumental challenge to go and seek life on another planet, because especially if that place, planetary bodies like Europa, its life, if it has life, had a completely different origin from life on Earth. And so do we need to expand our mind to what life is and what life could be in the cosmos to actually basically identify and determine that there is life on another world? And I think finding evidence of extraterrestrial life that has a completely separate origin

and evolutionary story from us will actually teach us quite a bit about what life really is. in the universe. Michael Wong, fellow Treki, thank you so much for coming to talk to us today about Europa and all the other

icy moons. My pleasure. Go Clipper. Go Clipper. Short waivers, if you like what we're doing here, leave us a review. It helps us out.

Also, if you liked this episode, check out our episodes on NASA's future missions to Uranus and our episode on whether Dune could really exist. This episode was produced by Jessica Young, and it was edited by our showrunner Rebecca Ramirez. Tyler Jones, check the facts. Quasi Lee was the audio engineer. Bet Donovan is our senior director,

and Colin Campbell is our senior vice president of podcasting strategy. I'm Regina Barber. Thank you, as always, for listening to Shortwave, the Science Podcast from NPR.