AILSA CHANG, HOST:
Time now for this week's science roundup from our friends at NPR's Short Wave podcast. Regina Barber and Aaron Scott are here with us. Hello to both of you.
REGINA BARBER, BYLINE: Hey, Ailsa.
AARON SCOTT, BYLINE: Hello. Hello.
CHANG: OK. So you have brought us three recent science stories that grabbed your attention. What are we looking at this week?
BARBER: How about lessons from wildfires, but from 13,000 years ago?
CHANG: Whoa.
SCOTT: And turning brain activity into rock music.
CHANG: Like it.
BARBER: And, of course, moon landings - one successful and one not so much.
CHANG: Love it. OK. let's journey into space first and start with those moon landings. What happened this week?
BARBER: So we just had two countries, Russia and India, attempt to land robotic probes on the moon within days of each other. Russia was first. It tried over the weekend, and it failed, adding to the suspense if India would succeed. Then Wednesday, India did it.
(SOUNDBITE OF ARCHIVED RECORDING)
UNIDENTIFIED PERSON: (Non-English language spoken).
BARBER: Its probe landed close to the moon's south pole. And this region of the moon is just really fascinating.
CHANG: What's so special about this area of the moon?
SCOTT: So our NPR colleague Geoff Brumfiel has been reporting on this story, and he says that this region is near where craters on the moon are in permanent darkness. And scientists hope that we'll find frozen water there. And, of course, water is a key resource that could potentially be used for future missions as, you know, drinking water for astronauts, of course, but also, the hydrogen and the oxygen that make up water could be broken up for rocket fuel or for breathable air.
CHANG: Whoa.
BARBER: Yeah. And the moon's south pole is a popular place. China is planning a mission there. And the U.S. wants to send humans there as a part of the Artemis program.
CHANG: Well, like you said, Russia failed in their mission. Do we have any idea of, like, why India was successful here?
BARBER: Well, this Russian mission was the first to go back to the moon since the days of the Soviet Union. They spent decades planning and building this lander because it was a proven Soviet design. But as it was preparing to touch down, the Russians lost contact with it. And when it comes to India, this is actually the country's second attempt at the moon landing after it crashed a lander in 2019.
SCOTT: So the trouble is it's really hard to land on the moon, especially for a probe being steered by a robot. There's basically no atmosphere, so the probe can't gently float down on a parachute like on Mars.
CHANG: Oh.
SCOTT: They have to use thrusters, and that involves a lot of sophisticated calculations that can be challenging for robots, despite all their fancy sensors. It was actually partly a thruster issue that contributed to India's crash in 2019. And so India's engineers learned from that. They beefed up the probe software and the hardware, and that likely played a role in their successful landing this time.
CHANG: OK. Well, next up, Aaron, you are moving us from a dark area on the moon to the band that made the album "Dark Side Of The Moon," Pink Floyd. Did you see what I did there? Did you like that transition?
SCOTT: I got that. Yes, indeed. We are doing Pink Floyd and brain science. A team of scientists wanted to know if they could recreate a Pink Floyd song that someone is listening to just by observing their brain activity.
CHANG: Wait. Like mind reading?
SCOTT: Yeah, pretty close. Ailsa, I'm guessing you know this song.
(SOUNDBITE OF SONG, "ANOTHER BRICK IN THE WALL")
PINK FLOYD: (Singing) All in all, it was just a brick in the wall.
CHANG: Is that the one that goes, (singing) we don't need no education?
SCOTT: Yes. Yes. Yes. Pink Floyd's "Another Brick In The Wall." Nicely done.
CHANG: Thank you. Thank you very much.
SCOTT: So what happened is a team led by researchers at the University of California Berkeley played this song to some epileptic patients who had a bunch of electrodes wired into their brain. Principal investigator Bob Knight explained that it was then like watching a pianist play a piano and reconstructing the song from what keys they played.
CHANG: Wow.
BOB KNIGHT: We're treating the electrodes in a way like the piano keys. You know, the sound comes in, goes to your auditory regions, activates brain cells. They generate an electric field. We record that electric field. That's our piano key.
SCOTT: Then the researchers fed all the data from those electrode piano keys into a machine learning program to see if they could reconstruct what the patients were hearing. And this is what they got.
(SOUNDBITE OF MUSIC)
CHANG: (Laughter).
BARBER: Wow.
CHANG: It's like the band is playing underwater. But, I mean, I can almost understand the lyrics, I guess.
SCOTT: Yeah. Bob says it would have been a lot more clear if they had more electrodes in each patient. But the Berkeley team thinks that this is really the first time that scientists have been able to reconstruct how the brain hears musical elements like melody and rhythm and intonation just from the neural signals.
CHANG: I mean, I get it's a neat parlor trick of neuroscience, but does it have any practical implications?
SCOTT: It does. It does. The long-term goal is an implantable speech device so that people who have trouble speaking because of something like ALS or a stroke can communicate through the device just by thinking about what they want to say. And Bob says being able to reconstruct music could improve some of these existing devices, which are really quite robotic.
KNIGHT: It would be like, I - love - you, as opposed to I love you. And I think music, because of its prosodic, emotional, melodic elements will actually make an eventual implantable assistive device more human.
CHANG: All right. Thank you, Aaron. Let's turn to our last story. Gina, so much of the world right now is dealing with these devastating wildfires, but I understand that you have brought us a story about fires from thousands of years ago?
BARBER: Yeah, 13,000 years ago.
CHANG: Wow.
BARBER: So there's this new study published in Science last week that touches on a debate that's been raging for over a hundred years. What caused one of the major extinction events that wiped out large mammals in North America like dire wolves, North American camels and the saber-toothed cat?
CHANG: How did they figure this out?
BARBER: So they went to the La Brea Tar Pits in Southern California, these, like, bubbling pools of tar that animals have been getting stuck in for thousands of years. And this creates fossils that researchers can study. Today these scientists dated and analyzed 172 specimens from seven extinct species and one that's actually still around - coyotes. And they looked at environmental data from that same time period to see if there were any links between animals dying off and their environment.
CHANG: So what did all these fossils tell them about the extinction?
BARBER: So I talked to one of the authors of the paper, paleontologist and evolutionary biologist F. Robin O'Keefe, and he said that after looking at the data, there was a clear overlap between mass deaths and wildfires that just jumped out.
F ROBIN O'KEEFE: It was like a line in the sand. I thought we would see like a slow decline going down because people are getting more common, but that's not what happened. It was kind of train wreck.
BARBER: A train wreck because there was such a massive die-off.
CHANG: Wait. So how could they tell that fires in particular caused this massive extinction event?
BARBER: Well, the team could infer wildfire activity by looking at charcoal accumulation. And this was in core samples taken from Lake Elsinore in California. They saw an increase of charcoal 30 fold that corresponded to the time Robin said there was a sharp disappearance of species.
CHANG: So fascinating. Can this tell us anything about the fires that are happening now?
BARBER: Yeah. Well, Robin says scientists like him are concerned because they've seen this before. A paleoecologist that didn't work on this study named Anthony Barnosky went even further by saying, quote, "what we are seeing today, increasing human pressures combined with and actually causing climate change, is like this lesson from the past on steroids."
CHANG: Geez. OK. That is Regina Barber and Aaron Scott from NPR's science podcast Short Wave, where you can learn about new discoveries, everyday mysteries and the science behind the headlines. Gina and Aaron, thank you guys so much.
SCOTT: Thank you, Ailsa.
BARBER: Thank you. Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.
