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Find and follow Your World Tonight from CBC News, wherever you get your podcasts. This is a CBC Podcast. Hi, I'm Bob McDonald. Welcome to Quarks and Quarks. On this week's show, new technology sheds light on the pterosaurs' mysterious tail.
So it was just, it looked like a tail, there's nothing on it, it's just bonds, and we shone the light of a laser, and suddenly, a tail drain completely preserved pops up. It was invisible to human eye, it only was visible in the laser. And a flying visit by gophers brings life back to a volcano-blasted landscape. They would go down...
more than a meter to be able to get some of the soil that had been buried below and bring it up to the surface, creating these little microsites that life could return to. Plus, Hawaii sees the return of a very special bird, desert ants' magnetic perception, and exploring some dark mysteries of our solar system. All this today on Quirks and Quarks.
This is the sound of an alala, a smart, charismatic, and chatty species of crow native to Hawaii. It's also a bird with spiritual significance to native Hawaiians. But that sound doesn't ring through the lush Hawaiian landscape like it used to. The alala is critically endangered, with only about 120 of them left, all in captivity, making it the world's rarest crow. They've been extinct in the wild since 2002.
And in the years since, attempted reintroductions to their native habitat on Hawaii's Big Island have all been unsuccessful. But recently, five young crows were re-released on a different Hawaiian island in the hopes of giving the alala their best chance yet at making their home in the wild once more. Mr. Bryce Mazuda is a Senior Conservation Program Manager with the San Diego Zoo Wildlife Alliance. We reached him in Volcano, Hawaii.
Hello and welcome to Quarks and Quarks. Thank you so much, Bob. Really happy to be here. First of all, tell me about the Hawaiian crow. What's it like?
Yeah, so alala are a unique and special part of Hawaii, and they also happen to be one of the rarest birds in the world. You know, they're the last remaining endemic corvid species from Hawaii, and there used to be at least five different species of corvids here. You know, in terms of appearance, they're sort of similar looking to a common raven, but alala have a straight bill, and their feathers are a little bit duller, almost slightly brown.
And I think, you know, most importantly, alala are an integral part of the people and the lands of Hawaii. So if alala thrives, then we all thrive here too. Well, tell me a bit more about that. Why is it so special? You know, I think alala are just so charismatic and unique. Alala have a diverse vocal repertoire. They have at least 24 different call types, which is more than the American crow and the common raven.
You know, alala also use sticks as tools. So they use these small straight sticks to extract a food item like an insect out of a crevice. And natural tool use is actually quite rare in animals, particularly for birds and including corvids too. And we found that 93% of all adult alala use tools without being taught by humans.
proficient and dexterous tool users. And also, you know, one more thing is alala, they help disperse and germinate native fruiting plants here. So we found that there's one native plant called ho'awa that didn't germinate unless it was first consumed by alala. Wow. Well, if this bird is so special, how did it become so endangered? Yeah, so over 100 years ago, alala were relatively abundant on Hawaii Island.
But since then, the population declined, and it's really because of habitat loss. And Alala are specialists from the forest. That's their preferred habitat. So the loss of the native forest habitat here, plus exotic diseases and predation by introduced mammals. So what efforts have been made to try to conserve it?
So, you know, Alala were declining, and by the 1990s, the population reached a low point of fewer than 20 individuals alive. So really at that point, Alala were on the brink of extinction. And so as a last resort, we brought birds into our care and started an intensive program at two facilities here in 1996.
And from those founding individuals, we're able to help increase the population from fewer than 20 birds alive in the 1990s to about 120 birds today. Well, why has it been such a challenge to reestablish the alala populations in the wild? So, you know, before the last releases on Hawaii Island, we exposed the alala to eel or the Hawaiian hawk. And the eel are a natural predator of alala.
Before release, all Alala exhibited competent anti-predator behavior. And then we released the Alala. And after release, we observed these same anti-predator behaviors, which was great. You know, we even saw Alala chasing eel in the forest after release. Despite all of this, and after a few years, more and more Alala passed away because of a variety of reasons. And eel predation was one of those reasons. So we ended up recalling and returning the remaining birds back to our facility.
So what's different about the release this time? You know, together with our partners, we just did our first release on the island of Maui. And the release site on Maui is in a wet forest habitat. And the Alala haven't lived in this type of forest for many years. Also, the eel, the Hawaiian hawk, it doesn't live on the island of Maui. So we'll be able to learn more and more about how Alala do in this.
slightly different type of environment, and in the absence of its natural predator. Well, Maui is a different Hawaiian island, and if you're introducing the birds there, are you concerned that they might disrupt the ecosystem as a sort of a new invasive species?
You know, of course, our hope is for the alala to thrive in the forest again, but we're also being very mindful of the potential impact that alala might have on the forest. So, you know, for example, there are rare and endangered snails found throughout all the islands in Hawaii. So we chose our release location on Maui carefully and intentionally chose it to be away from where some of these rare snails were previously found.
Because ultimately, you know, we want to help all native species thrive in the forest, not just alala. How did you prepare the birds for this release? So, you know, for example, we provided live insects to the alala before release. So they're ready to find these food items in the forest on their own. We ensured that the alala were able to proficiently eat from a supplemental feeder. So they could come back after release and return to that supplemental feeder.
and have more food available to them. We made sure that they were competent flyers and they could fly strongly while carrying a tracking device. And we also ensured that the group of five juvenile alala were all cohesive and got along well socially prior to release. So this way, after release, they're more likely to stay together and work together, which will help their transition to living in the forest. So how have the birds been doing so far?
I'm happy to share that all five Alala are doing great. You know, they're exploring the forest more and more. They're gradually moving away from the release aviary. And we see them eating native food items like insects and like fruits in the forest. Yeah, they're doing well. They seem to be enjoying their time in the forest again.
What's it like for you to see these birds back in their wild habitat? Oh, it's such a great feeling to be able to see Alala flying in the forest and living in the forest again. You know, I think there's been just so many dedicated and passionate people who have helped this effort over the years. So it's been...
Also really inspiring for me to work alongside, you know, neighbors and friends who are so committed to supporting the recovery of Alala. And not only just to see them in the wild, but to hear their calls once again. Absolutely. It's a beautiful sound to go into the forest and to have their voices there with us. Mr. Mazuda, thank you so much for your time. Thanks so much, Bob. Really appreciate it.
Bryce Mazuda is a conservation program manager with the San Diego Zoo Wildlife Alliance. Long before there were birds or bats, there were pterosaurs, great flying reptiles that soared the skies from the dawn of the age of the dinosaurs.
Scientists have known for years that pterosaurs flap their wings to generate lift and control their flying. Their fossilized bones told us that. But it's only been in the last decade or so that we've understood other aspects of their flight, as new technology has enabled the study of remnants of soft tissue left behind on those bones. A while back, a few paleontologists went on tour, visiting museum collections, including here in Canada at the Royal Ontario Museum.
to shine a new light on these early pterosaur fossils when they made an unexpected discovery about their tails. Dr. Natalia Jagerska is one of those paleontologists. She's from the Lyme Regis Museum in Dorset, England. Hello and welcome to our program. Hello, lovely to hear from you, all the way from Canada.
Now, what were you looking into when you went on tour to take a new look at the pterosaur fossils? We went around to see what things you can actually see in the fossils. So we rolled in with equipment called laser simulated fluorescence, which is basically an industrial laser.
that shoots on a fossil and that laser stimulates different elements that are inside of it, making them flourish in different colors. So you can see soft tissues inside of them, but also bones stick up better, the geology and the rocks underneath stick out better because a lot of things we are looking for are not visible or visible well with human eye.
Well, tell me a bit about that technology. It's a laser. You shine light on the fossils and see things the human eye can't see. Yes. So we can see the visible light, but that's not the only spectrum that exists. We have the infrared light and UV light and different minerals, things what the bones and fossils are made of, will have different properties which will react differently with different wavelengths. So when you have ultraviolet light or infrared light, like the laser, and we...
It's beginning to shine on the fossil. It sort of excitates it, and that causes it to emit additional musically electrons and shine in a different light. And things that will get excited will be small chemical irregularities. And things that cause those chemical irregularities might be remnants of soft tissues or invisible things or barely visible things. And that's what we sort of went and started looking for because we know things like...
Throat pouches, claws, beaks, skin, pads, scales, and wing membranes and fur and fuzz can pop out when you do this kind of laser-stimulated fluorescence. That's always exciting because you never know what you're going to see for the first time. It's amazing. It's almost like you're putting skin back on the fossil bones. It literally is.
Well, tell me about the pterosaur fossils that you were studying. What are they like? So we were mainly focusing on pterosaur that's mainly coming from Bavaria, so from Germany. And they used to live around the Jurassic period around 150 million years ago. They were similar in size to a seagull. So imagine quite slender wings, good taste for fish and snatching things from hands of other animals and long tails.
I think we've seen images or drawings of what pterosaurs look like with their long wings, and the wings are made of skin rather than feathers. But tell me about their long tails. What do they look like?
Okay, the first Pterosos to take flight around 200 million years ago in the Triassic, they had those long, humongous, very sturdy, very stiff tails. They were as long as the body of the animals sometimes, and they're quite robust. So that sort of doesn't make any sense. Usually when animals start flying, they lose the tails. But when Pterosos started flying, they had those long, long tails. And at the end of the tail, they have...
Weird tail veins, or just kind of weird kite-shaped patterns of unknown-for-now function. A tail vein on the end?
What does that look like? It really varies between species. In Ramparenchus, the fossil we looked at, it looks like a kite. Basically imagine a long line with a small fleshy kite shape that's kind of flat. And that kite shape changed the shape depending on the age of the animal. So in the Pterosaurus baby, it still looked like a small paddle. When it was a teenager or a young adult, it...
It had a kite shape and when it was an adult it looked more like a weird triangle on a heart. So we know that tail vein in Ramparcus pterosaurs changed the shape as the animal grew and we had known about it for a pretty long time because they only enough can preserve pretty well in those pterosaurs despite not being composed of bone or anything sturdy. It's just a membrane that usually is impressed at the end of the long tail.
So what then did you see when you looked at this kite-shaped vein at the end of a long tail with your new technology, your new laser? So it was just, it looked like a tail. There's nothing on it. It's just bonds. And we shone the light of a laser. And suddenly, a tail vein completely preserved popped up. It was invisible to human eye. It only was visible in the laser. And what was surprising is that those tail veins had a lot of internal structure.
So they had struts going up parallel and perpendicular to the main direction on the vein. So it looked like a lattice, something you might expect from, I don't know, a sail on a ship or a wing of a plane. It looked like a very intrinsic structural element that was quite fluid because those struts inside of it, they were not straight and robust. They looked quite wispy. And we assumed that must be some kind of internal structure that nobody has properly described previously.
So what went through your mind when you saw this lattice-like structure within this little vein? We have no idea what the tails are for. So there are two different theories. Either they were used for social signaling, so basically showing the age or status within a group, or as an aid in flight. Or maybe both, it's very hard to tell. So we can actually try to answer that question, because we now know what's inside of this very soft tissue.
Those kind of lattices, they look quite structural. So our main interpretation was then, if it's structural, it probably aided it with something. And when you have this flappy fleshy thing, having an internal fluid and dynamic structure might be.
kind of useful because when you have a lot of flags or sails, they like to flutter in the wind, especially when there's strong wind and they're going in one direction. And flutter is not very good. Basically, you're not very aerodynamic when you have a lot of flutter. It really hinders you moving around water bodies or air bodies.
So I'm just trying to picture this again. So we got the long tail that's almost as long as the body of the pterosaur. And then at the end of it is this kite-shaped vein that's sticking vertically up like the tail of an aircraft. Yes, those tails are quite asymmetrical. So one half is bigger than the other. And that asymmetry makes us think they were vertical rather than horizontal. Because when you have something...
that's horizontal and asymmetrical that wouldn't really work. So they possibly were weird vertical kite-shaped structures which tensed up when they had some wind blown on them. We have no idea if they were nicely decorated and colorful because no pigments popped up so far. So if we can know what was the function of the entire body, that can pave us away to knowing.
how overflight evolved, and seeing also why the pioneer disappeared. Because we have no idea what was that selective pressure which caused the evolution of flight in the first place and caused extinction of those pioneers. So if you find that it was colorful, it could have been for display. But what do you think it could have done for the pterosaur flight? What involvement would it have there? Oh, it's a very good question and something we have to actually try to do modeling of.
because right now we're just throwing interpretations. And in science, you have to prove that something you're actually suggesting is actually useful in flight. So maybe they were used to control when they were turning or help with braking, as a lot of birds use their tails to brake when they are flying. And there might be other membranes which contribute to that bigger story and can form a full picture of how those animals flew, which is...
Something that's very important to learn because they were the first flying animals, the largest flying animals to ever evolve. And that knowledge can be used to help us understand parachutes or material stensing in the wind. So good for designing of kites or tents. So it might seem like something esoteric, but actually once we can understand how those weird creatures functioned, we can copy and paste how they actually operated in that time and use it for our technologies.
Dr. Jagielska, thank you so much for your time. Okay, it was lovely talking to you. Dr. Natalia Jagielska is a paleontologist at the Lyme Regis Museum in Dorset, England. In 1980, Mount St. Helens exploded in what was the worst volcanic eruption in the history of the United States. It lasted nine hours.
annihilating the nearby landscape, leaving it buried in layers of ash. But in the aftermath, scientists conducted a test. What would it take to revive its surrounding ecosystems? Two years after the eruption, these scientists rounded up some nearby gophers and dropped them on the volcanic ash and pumice. They left them for just one day before retrieving them.
The idea was to investigate short-term changes to the land, but to everyone's astonishment, changes from this one-day trip still persist. Dr. Mia Maltz is an assistant professor of microbial ecology and soil health at the University of Connecticut. Hi, welcome to our program. Hello, thank you so much. It's great to be here. Well, first of all, just briefly tell me what happens to the surrounding area when a volcano as large as Mount St. Helens goes off.
The 1980 eruption, it created a whole range of different initial conditions because there was ashfall and the blowdown zone and the pyroclastic flow that created the pumice plane. And the heat was so intense that it decimated everything in its path. So what did the landscape look like after the eruption? There were...
golf ball to marble size pieces of pumice or tephra that was ejected from the volcano. And it covered it for many, many meters all the way around. Then further away, there was so much ash that was deposited that it was burying everything. But because the snow was on the mountain in May of 1980, it did create these pockets that were somewhat shielded by some of the
material, the tephra that was ejected from the volcano. Well, why did scientists in the 80s think setting gophers loose would be a good idea? Well, Jim McMahon, who is at Utah State University, he had been studying animals and small mammals and their processes. Since these animals are fossorial creatures, like those that dig, and also since animals often would disperse material like seeds and spores and defecate and...
start to create these conditions that may mimic mounds of earth that we might feel would be good for planting something in. So they're digging down and getting some of the soil that was buried and bringing it up to the surface where there was all this ash and pumice and tephra and creating these little micro sites that life could return to. Where did they get the gophers?
They were in a zone called Pinto Basin, and it just was outside where there were some meadows and forests and clear cut. And they put them on a helicopter and they brought them over to the sites where the pumice plane had left basically nothing in its wake. They dropped off the gophers in these exclosures. So the gophers couldn't go anywhere, just was able to move around this one meter square area. Well, wait a minute. How do you round up wild gophers and put them in a helicopter?
Well, you can trap them. And everyone was moving around in helicopters after the Mount St. Helen blast because that was the only way you could really get in and out. And also they didn't know when there might be another blast. So being able to get out of there quickly was really imperative.
Boy, well, I've been to Mount St. Helens a few times and in areas where it's still covered in that stuff, it's just gray ash. I mean, there's nothing there at all. So when the gophers were put down on that type of soil or that landscape, what did they do? Well, they dug down and they found...
pockets of soil that were very deep, and they brought it back up to the surface. And also they carried underneath their claws and on their fur and in their feces, spores and seeds from other ecosystems that were nearby. And they deposited these little mini ecosystems in their fecal pellets. And then they dug and they mixed it all around in with the soil that was coming up from
below the ash and the pumice. So they created these little microsites that were like little mini ecosystems that had plant materials, spores from fungi and bacteria.
as well as a growth medium, the soil that they were able to bring up. And since you've seen the landscape and know that in some of these areas where there's all this pumice, being able to have even a little bit of fertile soil is like a gift to the successionary processes where plants could then root and thrive and be able to get established in these environments.
How far down into the ash did the gophers have to dig? That's a great question. They would go down more than a meter to be able to get some of the soil that had been buried below and bring it up to the surface. So what changed in the first few years after this experiment? The mycorrhizal started to spread. Some of the plants that were there became established. Also, more animals returned. There were herds of elk that crossed the landscape.
The landscape started to fill in slowly, slowly, but it was accelerated in the areas where the gophers were. So what are the changes like today? There's lupine flowers that are in bloom. One thing is that there's less erosion.
in the areas where the gophers are. And in the case of nutrient retention, there's more carbon and there's more nitrogen that's stored in the soil where the gophers were than even in these paired plots where there weren't any gophers left for 24 hours. So we can see that both prevention of erosion and soil aggregation, as well as retention of nutrients and also carbon storage is something that we can see even 40.
years down the road. Just one last thing. We're hearing about a lot of volcanic activity today in Iceland, Mount Etna is going off. Do you think gophers should be sent to these sites as well? Well, I think that if we can think like gophers, then we can think about...
what kind of things could be helpful. But I would say, yes, gophers could be very beneficial after some of these other eruptions because they really accelerate the succession of evolution and the community assembly following the big disturbance. I do this work post-fire as well. Right now, there's the fires in Los Angeles and there's often large fires.
that burn so hot that they also decimate some of the microbial communities and some of these plant-supporting fungi. So I've been working on a project post-fire called the Phoenix Project, Fire Ecology Network and Cross-Site Studies, where I look at moving microbes to the post-fire landscape and see what sort of an effect it has on nutrient retention and soil aggregation and erosion, similar to what we did at Mount St. Helens. Dr. Mons, thank you so much for your time.
Absolutely, yeah. I'm very thankful to be a part of this study. Dr. Mia Maltz is an assistant professor of microbial ecology and soil health at the University of Connecticut. From the Los Angeles Times, this is Boiling Point. I'm Sammy Roth. I've been reporting on energy and climate change in California and across the American West for a decade. I'll be asking scientists, politicians, activists, and journalists the same questions.
What are the challenges we face to building a better world? And what are the solutions we need to embrace, even when it's hard? Boiling Point will be available everywhere you listen to podcasts, starting January 16. I'm Bob McDonald, and you're listening to Quirks and Quirks on CBC Radio 1 and streaming live on the CBC News app. Just go to the local tab and press play wherever you are. Coming up later in the program...
Stealthy objects making their mysterious way through our solar system. Astronomers identify a population of dark comets. As we saw the first one and Oumuamua, we started searching in a more systematic way in the entire catalog for cases that could be similar. And in just a couple of years, we were able to find a total of 14 objects in the solar system. The world is a big place.
And for animals, finding their way around it can be a challenge, especially in landscapes without a lot of obvious features to navigate by. So, some animals have found ways to follow invisible landmarks. In particular, animals as diverse as birds, fish, sea turtles, and rats have evolved to detect the Earth's magnetic field, using it like a built-in compass in ways we don't entirely understand. One distinctive example is the desert ant.
because a new study has found these insects are apparently using the magnetic field to navigate their featureless landscape in a unique way. Dr. Pauline Fleischman is a postdoctoral researcher at the University of Oldenburg in Germany. She led the study. Hello and welcome to our show. Hello and thanks for having me. First of all, tell me a bit about the life of a desert ant. What's it like?
Desert ants are eusocial insects. That means that they all live together in one nest below the ground. And the queen is the mother of all the workers, and these are all sisters. In order to provide for the colony, single ants have to leave the nest, and then, when they find food, return to the nest as soon as possible, because it's very hot. Well, what's the environment like that they live in?
So some desert ants live in real desert like the Sahara, but the ant species I work with lives in southern Europe, particularly in Greece, in a pine forest. What do they eat? They are scavengers. That means that they look for everyone who did not survive the heat, for example, other insects, and they bring home these food items to their colony.
Well, how is this desert ant able to navigate its way, especially through sandy deserts like the Sahara? Desert ants are famous for their navigational toolkit and especially for a mechanism called path integration. To do so, they combine directional information and distance information.
to calculate a so-called home vector. Then they can follow this home vector in a straight line to return to the nest. In addition to that, they use almost any cue available, which might be visual landmarks, the crown structure, olfactory cues, because they need to make sure that they return to the nest as soon as possible.
Okay. Now, do they involve the magnetic field of the Earth like other animals do? Yes, they do. When they leave the nest for the first time, they have to acquire all information they need to navigate successfully. The ants in the pine forest, they perform so-called periods during which they turn back to their nest entrance, which is a tiny hole in the ground, in order to memorize how their way...
to return to the nest looks like. So they turn back, and we assume that they take a snapshot of their homing direction, which they can then follow when they want to go home. They need a reference system, and that is indeed the geomagnetic field. Well, how are they actually able to detect the magnetic field of the Earth? We don't know how they do it. We just know that they rely on the magnetic field to align their gaze directions.
How is the way the ants use the magnetic field different from the way other animals, like, say, birds? So many migratory animal species rely on the magnetic field by using a specific characteristic, which is the inclination. The inclination of the magnetic field is the angle between the field lines and the...
Earth's surface. And at the poles where the field lines enter, it's about 90 degrees, whereas at the magnetic equator, the field lines are parallel to the ground. And since this varies in a predictable way, migratory animals can make use of that. However, the ants travel for relatively short distances. I mean, for the ants, it's quite long because they move several hundred meters, but
For the globe, of course, that's a short distance. So the inclination does not change. What we could show now in our study is that they do not rely on the inclination, but on the polarity. So they can detect where magnetic north is, as also a handheld compass will do. Oh, I see. So it's the difference between knowing how far north or south you are by looking at the angle of the magnetic field to the ground, or knowing which direction you're facing. Exactly. How did you study this in the end?
So we work in a pine forest in Greece and we bring our equipment to do our experiments in the natural habitat of the ants. And for this experiment, we needed a 3D Helmholtz coil, which is a magnetic coil with which you can manipulate the magnetic field in a very controlled and homogeneous way. And we manipulated...
either the vertical component or the horizontal component or both at the same time to change direction, polarity or inclination of the magnetic field. And what we could show is that we can make the ants gazing towards the fictive position of their nest entrance induced by our magnetic coil when we change the direction of the magnetic field or the polarity, but when we only change the inclination, the ants
do not show a different behavior, but gaze towards the actual nest entrance. So what happened if you changed the polarity from north to south? When you sit next to the coil and you observe the animals, you can actually see that when you changed the polarity, that they gazed towards a different point than the nest entrance in the table. So you can almost steer the ants by changing the direction of the magnetic field. Yes.
Wow. What impresses you about these ants that are so tiny and yet they're capable of navigating using all these different cues, geography, magnetic fields, celestial? Yeah, it's amazing. I mean, the desert is a really special place. And when you are human, you realize that you would not survive there for a very long time. But then when you watch them, it seems so easy to find your way in this environment.
an amount of time they spend into performing these learning works. So if they come out, they perform these learning works up to three days, but they survive only for a week or sometimes 10 days when they are outside. So it means that they undergo both behavioral and neurobiological plasticity, which is just amazing. So much effort.
Yes, they learn quickly. Yes. Dr. Fleischman, thank you so much for your time. Yes, thank you very much. Dr. Pauline Fleischman is a postdoctoral researcher at the University of Oldenburg in Germany. In 2017, a mysterious object appeared in our solar system. Astronomers had never seen anything like it. It was cigar-shaped and dark.
perhaps over a hundred meters long, and its trajectory suggested it came from outside of our solar system. It was dubbed Oumuamua and captured the world's attention, briefly, as the scientific community tried to figure out just what it was. And fascinatingly, Oumuamua showed up just as NASA researchers were analyzing another strange object. They ended up calling it the asteroid that wanted to be a comet, because it didn't appear to be quite either.
That led them to look for more of these unusual objects that didn't fit neatly into any category of known objects in our solar system. First, they found six others, and more recently another seven, which finally allowed scientists to better understand them.
Dr. Davide Farnakia with NASA's Jet Propulsion Lab in Pasadena, California, has been on the case since the very beginning. He's a navigation engineer with the team that keeps an active lookout for near-Earth objects that could be on a collision course with our planet. Hello, Dr. Farnakia. Welcome to our program. Thank you for having me. First of all, tell me about the first unusual object that you were studying when Oumuamua showed up.
Well, so this first object was called 2003 RM. This object was discovered in 2003, as the name suggests. And one day we noticed that the data we were collecting to track it were not matching exactly predictions, which is something that is not that common for us. We have very good models to predict the motion of objects in space. So when an asteroid is not located in the observations where we predict, something strange is going on.
Well, how was this object acting in a way that was not predicted? So in order to match the data, you needed to add an additional acceleration to the motion of the object. So most objects in space have their motion that is completely described by gravitational forces. You have the sun, the biggest body in the solar system that is doing the heavy lifting, but you also have the planets and other bodies, asters and comets that can perturb each other. But this object needed something extra.
And that was the anomaly. So we computed how large an acceleration we needed. This was a non-gravitational perturbation to separate that from the gravitational forces. And we realized that that acceleration was way too large for an asteroid. Okay. So we were surprised and we said, well, we better take a closer look at this one. Let's use some of the best telescopes we have. The next time this object is observable is 2018. Let's get deep images and see if this object looks like a comet.
Now, comet and asteroids are different because when you look at images, comets have that beautiful tail. And that is caused by ice on the surface that starts sublimating as the comet gets closer to the sun. So we waited until 2018 and we looked hard and we could not see any indication that this object was a comet from the images. No tail, no activity whatsoever. This looked exactly like an asteroid would look like.
And so that's why we were kind of surprised. And I would say that this was a nice segue to what we had with Oumuamua, because Oumuamua was a very exciting discovery, first interstellar object to ever be discovered in the solar system. And when we observed it, it looked like an asteroid, no activity whatsoever.
But as we were tracking its motion on its way out of the solar system, we realized that also this object, Oumuamua, needed an extra acceleration. And this acceleration is really compatible with what we see for comets, not what we see for asteroids. So we're kind of in this situation that we don't really fully understand if the object should be classified as an asteroid or a comet.
Okay, so let me see if I got this right. This thing looks like an asteroid because it doesn't have a tail like a comet, but it's moving like a comet because...
Comets, with that icy stuff being blown off, makes them shift in their motion. It gives them that extra motion. So this thing's got the motion, but not a tail. Is that it? That's exactly right. So comets usually have this tail, and as the material leaves the surface, they get this extra thrust as they move in the solar system. This object, 2003 RM, but also Oumuamua, moves like a comet. There is this extra thrust, but it doesn't look like it.
It looks like an asteroid. Okay. Now, since then, you've also identified a total of 14 of these difficult-to-define objects in our solar system. So how similar are they to the first one that you found? Well, so as we saw the first one and Oumuamua, we started searching in a more systematic way in the entire catalog for cases that could be similar. And in just a couple of years, we were able to find a total of 14.
objects in the solar system. Some of them look like the first object, 2003 RM. They're fairly large, a few hundred meters in size, and they're located on orbits that are more distant to the Earth. They get close to the orbit of Jupiter. And so the orbits really look like that of Jupiter family comets, which would confirm what we found by analyzing their motion and this extra acceleration. Then there is a second category.
that is composed by objects that are smaller and they are closer to the orbit of the Earth. And in that case, what we noticed is that there is this acceleration that is pushing the object a little bit outside of the orbital plane. Every object in the solar system moves on an orbit that really lies on a plane, and this acceleration is pushing outside. That's not something you expect for asteroids. And so there is that anomaly as well that we're trying to sort out.
Okay, so if these objects look like asteroids but behave like comets, but they're not either, what are they? Well, that's a good question. I wish I had an answer. This is the exciting part about science. You know, some people like to think that science always has all the answers. We'll eventually get an answer, but it's when you find something that you don't expect that you learn something exciting in science. The big benefit of these dark comets is that they're permanent resident of the solar system.
Always new opportunities to observe them and study them in more detail. In particular, one of these objects, 1998 KY-26, is the target of the Hayabusa 2 extended mission. They're going to go there in 2031, and that might really provide a lot of answers that we're looking for.
Okay, you're calling them dark comets, but what do you think is causing them to behave so strangely, to move in these odd directions? I can do some speculation, which is fine as long as we recognize it is speculation. I think that the larger ones that are on orbits similar...
to that of other comets i think they're just weak comets they have some sort of activity that can cause this acceleration but they just don't release as much material as other comets so i think if we had the opportunity to get a closer look at them we would find something like this the smaller objects that are
closer to the orbit of the Earth, it might be that they have strange shapes or rotation states that can cause some sort of acceleration that could be due to radiation forces that are projected in a strange way when you actually compute them. But we don't have the answer yet. But is it possible that it's water coming off these objects that's causing them to accelerate?
It is theoretically possible, especially for the distant ones, the larger objects, but it would have to be a limited amount of water, not as much as you see on other comets. Right, not enough to make a tail. So does this change our idea of how asteroids or comets brought water to the Earth? Well, maybe what we can say is that there might be an additional source of objects that could have brought water.
to the Earth. And so that might actually make that hypothesis stronger. It sounds like there may be more of a continuum between what defines a comet and what defines an asteroid. These dark comets might be between them.
That might well be. And another thing that I would mention is that also asteroid Bennu was the target of the OSIRIS-REx mission. When it visited asteroid Bennu, it saw some ejection of particles, nothing that you would be able to see from Earth, but that the spacecraft in orbit about the asteroid can detect. And so maybe there is more of a continuum of increasing activity as you transition from asteroids to comets.
Now, there's one more strange possibility here that came up when Oumuamua first came through our solar system, that maybe these bizarre things are disguised alien spaceships. No, well, I would say extraordinary claims need to be backed up by extraordinary evidence. And so I don't think we have any of that extraordinary evidence that we would need for that claim. Oh, okay. Dr. Farnokia, thank you so much for your time.
Thank you for having me. Dr. Davida Farnakia is a navigation engineer with NASA's Jet Propulsion Laboratory. One of the reasons scientists love meteorites is because they're a time capsule of the building blocks that gave rise to the solar system. But tracing back their history is a painstaking process.
Until recently, we only knew the origin of 6% of the known meteorites that have rained down on Earth. But in a recent series of discoveries, astronomers have been able to trace the lineage of 90% of those meteorites. And they've built a kind of family tree that shows how they came from asteroids that broke up at four different time periods in our distant past.
One of the first clues about where these meteorites came from stemmed from a discovery of a limestone deposit in Sweden, full of fossilized meteorites that landed on our planet after an asteroid broke up 470 million years ago. Dr. Mikael Marse was part of the team that made these discoveries. He's an astronomer at the European Southern Observatory in Santiago, Chile. Hello and welcome to our show. Thank you for having me.
First of all, tell me about the first clues that came from the buried meteorites from Sweden. There's this team of very clever geologists from Sweden that thought they would look for fossil meteorites in limestone rock on our planet. And they found this limestone rock in Sweden from 470 million years ago.
And these limestone rocks were full of micrometeorites. And here we're talking about a factor of 100, maybe 1,000 or 10,000 more meteorites that we are receiving today on our planet. So you have to imagine the night sky at the time must have been a constant firework of fireballs. Most of the life on Earth at the time was still in the ocean. So I'm not sure that the squids and starfishes and trilobites that were populating our oceans really appreciated the show.
It must have been something very impressive. Wow, 470 million years ago. So how were you able to trace the actual age of these meteorites? Yes, so the age of the meteorites, we can measure their argon isotope age of these meteorites.
There is some natural radioactive decay happening in the interior of asteroids and in interior of rocks in general. So you will create these argon atoms. But if the asteroid was heated by something very powerful, it will release these isotopes. So the asteroid will degas. And we know from the present day ratio of isotopes when that happened. In the case of L-chondrites, which we've...
studied. This happened 470 million years ago. There's another way to get the age of the meteorites, which is what we call the cosmic ray exposure age. And this tells you how long the meteorites stayed in space. And in the case of Alchondrite,
The peak of the age distribution is around 40 million years. So it means that a secondary impact happened much more recently on the same body that brought the fossil meteorites that were found in the limestone. And we know those are the same meteorites because the ones falling on our planet today have the same isotopic age as the age of these limestone rocks.
And we know the secondary impact happened 40 million years ago because of the cosmic ray exposure ages of these meteorites. So we have two events. We have one at 470 million years ago, another at 40 million years ago. And you're saying they came from the same object in space? Yes, this is correct. They come from the Massalia asteroid. So this is a very big asteroid, about 150 kilometers in size. And it was impacted twice.
So we had this first impact 470 million years ago, which dominated the flux of meteorites to our planet for a few million years. And then a secondary impact happened about 40 million years ago. And we're still receiving today a lot of meteorites from this secondary impact. Wow. What was causing these impacts? So in the asteroid belt, the region of space between the orbits of Mars and Jupiter, there's...
millions of asteroids in that region of our solar system. And from time to time, out of luck, some of these objects enter in collision. And when that happens, you fragment the asteroids and you create what we call a collisional cascade. Because the first collision...
The fragmentation of the main object will create a lot of small fragments that might enter in collision between each other. And this collisional cascade over time scale of million years or tens of million years. Dust and meter size objects will be very efficiently produced and it will be transported to the Earth by non-gravitational forces. In particular, the solar radiation is very efficient.
to move meter-sized bodies and dust in our solar system. Oh, I see. So you have a large object, it's hit by another one, and then the shrapnel that comes off that can either trigger more collisions or stuff is thrown down towards the Earth. Yes, this is correct. And these single collisions can produce, at meter size, about tens of thousands billion fragments.
So in English, I think that would be 10 trillion fragments. Wow, that's a lot. Yes. So at meter size, you can produce for a few million years a number of objects that is comparable to the total number of objects in the whole asteroid belt. Wow. Now, these two collisions, 470 and 40 million years ago, how much of our meteorites that we have here on Earth does that comprise?
meteorites from that 470 million-year-old impact anymore. 37% of the meteorites, which are the L chondrites, are coming from this 40 million-year-old collision that happened on asteroid 20 massalia. And then we have identified two more impacts, which happen in the coronis family. So coronis family is around 2 billion years old.
But within that family, there have been more recent collisions around 5.8 and 7.6 million years ago. And these secondary families are responsible for 34% of meteorites. And here we are talking about the H-type ordinary chondrite. What was it like for you now to understand the origins of most of the meteorites that have fallen on Earth?
Well, it was very exciting. So finally, we had a coherent picture for the origins of most meteorites falling on our planet. So our two studies that were published in Nature focused on these two groups of meteorites, the ordinary H and L chondrites. Then we decided to apply the same methodology to other classes of meteorites, including carbonaceous chondrites, which are a type of meteorite that form further away.
in our solar system with respect to ordinary chondrites, and other minor type of meteorites. So in total, we're capable of explaining about 90% of meteorites falling on our planet. But I should say this includes the 6% that were previously known, and those are the ones coming from our Moon, planet Mars, and another very big asteroid called Vesta. What's the take-home lesson here when we put all of these findings together? Before our studies,
We could think, OK, maybe we're seeing all these different types of asteroids in the main belt. And so we should expect that what is falling on our planet is a blend of everything we observe in the asteroid belt and more generally in the solar system. But this is not the case at all. Recent collisional events in the asteroid belt are completely dominating the flux of meteorites. So we have these two categories of meteorites at the moment.
H chondrites, L chondrites, that together represent 70% of the falls on our planet. And this is coming just from three collisions, Massalia 40 million years ago and Coronis 5.8 and 7.6 million years ago. That's amazing. Dr. Marseille, thank you so much for your time. My pleasure. Dr. Michael Marse is an astronomer at the European Southern Observatory in Santiago, Chile.
And that's it for Quirks and Quarks this week. If you'd like to get in touch with us, our email is quirks at cbc.ca. Or just go to the contact link on our webpage at cbc.ca slash quirks, where you can read my latest blog or listen to our audio archives. You can also follow our podcast, get us on SiriusXM, or download the CBC Listen app. It's free from the App Store or Google Play. Quirks and Quarks is produced by Rosie Fernandez.
Amanda Buckowitz and Sonia Biting. Our senior producer is Jim Lebens. I'm Bob McDonald. Thanks for listening. For more CBC podcasts, go to cbc.ca slash podcasts.