IRA FLATOW: This is Science Friday. I’m Ira Flatow. Later in the hour, using soil and poop samples to trace back the evolutionary roots of antibiotic resistance. And there’s a new math teacher in town, and she’s dressed in drag. Yes.

But first, surprising news from the FDA today, which is now delaying its decision on whether to approve a new Alzheimer’s treatment called donanemab. The news comes as a surprise because data shows that the drug made by Eli Lilly and company slows down cognitive decline by a little bit. The drug was expected to get approved this month.

The reason for the delay? Regulators want an independent panel to look more closely at the unique design of the drug trial. We’ll continue to follow this story in the coming weeks.

In other news, in 1977, NASA launched Voyagers 1 and 3. Their mission? To explore the farthest reaches of our solar system and beyond. Their space treks were– they’re only supposed to last about four years, but you know what? It’s been almost 50.

But since November, Voyager 1 has been sending gibberish back to Earth. Oh no. Brings up the question, could this be the beginning of the end of Voyager 1’s mission?

The week was full of great stories. And joining me with more about this one and others, Maggie Koerth, science writer, editorial lead at CarbonPlan, based in Minneapolis, Minnesota. Welcome back, Maggie. Always good to have you.

MAGGIE KOERTH: Thanks so much. It’s always good to be here.

IRA FLATOW: This is sad news, these voyages have gone where no spacecraft has gone before, they made this grand tour of the solar system, the flyby of other planets. What’s Voyager’s future, do we know?

MAGGIE KOERTH: Yeah. I mean, this is so meaningful both scientifically and just existentially. This is a beloved piece of equipment. Right now, it is– the address for Voyager would be something like Voyager 1, interstellar space, outside the heliosphere. That’s the sun’s direct zone of influence. It’s more than 15 billion miles away from us. So it’s not like we can just pop out there with a tow truck.

Nell Greenfieldboyce at NPR described it as sort of like suffering from an electrical stroke. It’s this elderly piece of machinery. Everything it’s sending back is just this alternating 1 and 0 instead of real binary data. And the problem seems to be in the flight data computer, which sounds fancy, but remember, we’re talking about 1977 technology here. And your car key fob is now a more powerful computer than Voyager 1.

IRA FLATOW: So we don’t know if it’s a fixable thing or not.

MAGGIE KOERTH: We don’t. It’s survived glitches before but nothing this major. The scientists actually tried turning it off and turning it back on again. And that did not work. A lot of the people who designed this thing are actually dead now. So we can’t even go consult all of the Voyager experts. And just sending and receiving a message takes 45 hours round trip.

But it’s also reaching the end of its life anyway. So it’s powered by nuclear generators. And those aren’t going to keep going really past 2027 or 2030. Even if they do get it back online this time, we’re really at a point now where we all have to figure out how to make our peace with this thing. You’ve got to give it thanks. We’ve got to wish it well, let it go. As Spock said, “V’Ger must evolve.”

IRA FLATOW: There you go. Thank you for that, Maggie. I feel better. It is sad but, it has had a fruitful life. So let’s get back to terra firma literally for a bit, a story about– this, I think, is fantastic, trees detecting neutrinos, Maggie.

MAGGIE KOERTH: Oh, I love this so much. So neutrino is actually Italian for little neutral one. And that’s exactly what these are. They’re subatomic particles with no electrical charge. And they’re so small that scientists thought they had no mass at all for many years.

It’s also the most abundant type of subatomic particle in the universe, to the point that 100 trillion of them just pass through your body in the last second. But paradoxically, when you get that many super tiny things, passing through is mostly all they do. They’re so small that they can slip between larger atoms without interacting at all.

And that means if you want to detect them, you need to do it with something really, really, really big. When you get that big, it’s less convenient to build something than to use these very large objects that nature has already blessed us with, like forests full of hundreds of thousands of trees. And that is the proposal being made in this prepress paper by researchers at the University of Kansas.

IRA FLATOW: Wow. You mean so the leaves, the branches, they would be little antennas? I mean, well, they’re big antennas. They’re big trees.

MAGGIE KOERTH: Tree antennas. There is other research outside of this paper that shows that trees can pick up radio waves, though it’s not as simple as just hugging one and keeping an ear open. You’d have to wrap wire around each trunk. And you have to hook it up to electronics that can interpret the signals.

And other researchers outside of this paper also told Emily Conover at Science News that it would be a hard thing to pull off. And you’d need to do a lot more study because we don’t know things like what happens to your tree antennas when they go through a deciduous cycle and all the leaves fall off? So it’s not a perfect system.

But, but– and here’s the really cool thing to me– researchers already use nature to detect neutrinos. The IceCube neutrino observatory uses a cubic kilometer block of Antarctic ice. And there’s this other neutrino observatory that is currently under construction that’s going to use the entire Mediterranean Sea.

IRA FLATOW: Wow. Wow. I love that stuff. OK, let’s talk about something that sounds like it’s in outer space, but it’s here. There’s a new study about star dunes, just in time for the new Dune movie, right? What’s a star dune?

MAGGIE KOERTH: Well, so star dunes are these massive pyramidal sand dunes. They form on Earth as well as in Mars. We found them on Saturn’s moon of titan. And they can actually move without falling apart. And a recent study found one in Morocco that is 13,000 years old.

IRA FLATOW: Whoa. Whoa, so just found one of them? How do you know how old a sand dune is?

MAGGIE KOERTH: Yeah, so this is where it gets really fun. So Lala Lallia, which is a Berber name, and it means sacred high point, it’s 238 feet high. It’s 2,200 feet wide.

But measuring the age of a pile of sand is really hard. And it turns out, though, that grains of quartz that make up the sand, they all store energy from the sun. And they can release that energy in the form of light. And the level of brightness of that light can tell the scientists how long ago the grain of quartz was last exposed to the sun.

So the trick to this was extracting sand from inside of the pyramid, getting it back to a darkroom condition in the lab without exposing it to the sun again and ruining the measurement. And to do that, they used an old piece of drainpipe, Ira.

IRA FLATOW: They MacGyvered it to bring it back to the lab. That’s great. Speaking of old, old grains of sand, our next few stories are about origins. And this one is a study that hints at the origin of cells, Maggie. Tell us about that because we’ve been wondering about that ever since the Miller-Urey experiment in 1952.

MAGGIE KOERTH: Yeah. Well, this is a couple of interesting studies. So we know that early Earth primordial soup, chemicals– you got your cyanide. You got your glycerols. And we know that at some point, roughly 3.8 billion years ago, living cells.

But how you get from the soup to the nuts, so to speak? Right, how do you get a–

IRA FLATOW: Love it. Love it.

MAGGIE KOERTH: –discrete thing with walls and the ability to metabolize and generate energy? That’s the big mystery. So we had two studies recently that recreated the conditions we think existed on early Earth in a lab. And we’re able to coax chemical compounds into forming some of these crucial cell structures.

IRA FLATOW: That is really cool. Let’s move on to our next story about our tails or lack of them, suggesting why we lost them, evolutionary, right?

MAGGIE KOERTH: Yeah. When our common ancestors split off from monkeys 25 million years ago, it doomed us to a life without a way to carry a drink and a plate and still eat at a party. And now scientists have pinpointed a mutation, maybe not the only one, but a mutation that seems to have been a cause of this change.

And there’s a couple of things that make it really, really cool. So first, we’re talking about something called a transposon, which is a repetitive little snippet of DNA that gets inserted into a human genome from something else. Some transposons we know started out as viruses. In other cases, we just have no clue where they came from.

And this particular transposon inserted itself into a hunk of a gene that isn’t even responsible for making anything. It’s noncoding data. And yet when you put the transposon in there, no tail. You delete tails. So the researchers even replicated this with mice.

IRA FLATOW: Wow. So do we still have this transposon?

MAGGIE KOERTH: Yeah, we do.

IRA FLATOW: Does it have any side effects? Because we’re not using it.

MAGGIE KOERTH: They found this by analyzing 140 genes that are associated with vertebrate tail development until they found this one gene, TBXT, that had a chunk missing in monkeys that was present in primates. And they were able to replicate this in mice because the mice also don’t have this chunk. So when you stick the chunk in there in the mice, they lose their tails.

But the other interesting thing about this is that when you do this, the mice also end up with an increased risk of spina bifida, which is this birth defect where the spine doesn’t fully seal shut during development. So it is possible that a random side effect of losing our tails is the risk of this birth defect.

IRA FLATOW: Speaking of ancient, there’s a story about someone who stumbled upon a dinosaur while taking his dog for a walk.

MAGGIE KOERTH: So two years ago, this 23-year-old Frenchman named Damien Boschetto just found a whole heckin’ dinosaur bone sticking out the side of a cliff. Ira, this is massively unfair of him to live out my childhood dream. They eventually found 70% of this titanosaur in this spot, which is really amazing because you’re talking about a dinosaur that’s not really common in Europe. And that’s a really complete skeleton to find, too.

IRA FLATOW: That is cool. And so the guy, did it change his life at all, make him richer or whatever, when you find a big dinosaur?

MAGGIE KOERTH: Yeah. I mean, two years ago, he was just an amateur fossil hound. But then he spent those two years helping scientists dig up this skeleton. And he is now in college working his way towards a PhD in Paleontology. That jerk.

IRA FLATOW: You don’t mean the person. You mean the pulling of the bone.

MAGGIE KOERTH: [LAUGHS] Sure. That’s what I mean. I have nothing against this man who’s living my dreams.

IRA FLATOW: There you go. Maggie, always a pleasure. You bring us such great stories. Thanks for taking time to be with us today.

MAGGIE KOERTH: Thank you.

IRA FLATOW: Maggie Koerth, science writer and editorial lead at CarbonPlan, based in Minneapolis.

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