Around this time last year a space rock crashed into the Earth above Chelyabinsk, Russia. It brightened the skies for hundreds of kilometers, broke windows and injured many people. Let’s look back at the event. What happened, and what did we learn?
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Pamela Gay: This episode of Astronomy Cast is brought to you by Swinburne Astronomy Online, the world’s longest running online astronomy degree program. Visit astronomy.swin.edu.au for more information.
Fraser Cain: Astronomy Cast, Episode 334: Chelyabinsk, One Year Later. Welcome to Astronomy Cast, our weekly facts-based journey through the cosmos. We help you understand not only what we know, but how we know what we know.
My name is Fraser Cain. I’m the publisher of Universe Today, and with me is Dr. Pamela Gay, a professor at Southern Illinois University Edwardsville, and the director of Cosmoquest. Hey, Pamela. How are you doing?
Pamela Gay: I’m doing well. How are you doing?
Fraser Cain: A little crazy, actually, now that you –
Pamela Gay: You are over-caffeinated.
Fraser Cain: I am over-caffeinated, it’s true, yeah.
Pamela Gay: I am recovering from the flu, so we’re a great pair today.
Fraser Cain: Alright it sounds like it’s been week after week this you’ve been getting your Astronomy Cast, just like normal, we’re actually recording two of them today just after we recorded the Weekly Space Hangout, so yeah. It’s very high energy. I’m pretty jazzed up. Is there any other announcements, anything interesting to talk about?
Pamela Gay: Just a reminder, we have all the apps. There’s a 365 Days of Astronomy app. There’s an Astronomy Cast app. There’s a Universe Today Phases of the Moon app. There are two, count them, two, but only available on Android, Cosmoquest apps, so if you want to support the shows and get something that you can go, “Look,” and learn, and have fun, go get apps, please, please.
Fraser Cain: All the apps. Download all the apps. Cool. Then, I just wanna remind people that we’re making our videos on Universe Today, and they’re available now on iTunes, so if you wanna download the videos and have them show up on your mobile device at the time of your choosing and watch them, you can go to universetoday.com/video, or universetoday.com/audio, and you can subscribe, or you can get them on iTunes as well. Cool, let’s get rocking.
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Fraser Cain: Around this time last year, a space rock crashed into the earth above Chelyabinsk, Russia. It brightened the skies for hundreds of kilometers, broke windows, and injured many people. Let’s look back at the event, what happened, and what have we learned. Can you believe it’s been a year?
Pamela Gay: I know. It was one of those events where I was not quite at the dead asleep stage, but at the, “I’m asleep in the bed is so warm stage,” and my phone started going off. I pick it up, and Nicole, Noisy Astronomer, Nicole Gugliucci, was basically like, “Something happened in Russia. Get on the internet right now.”
That actually caused me to get out of my nice bed and go to my keyboard in the middle of the night. It was unclear exactly what had happened other than it was a very bright object. That could be denied, and YouTube videos were going up left and right. I think the first thing that we learned was that Russia has so many terrible drivers that everybody has dashboard cams.
Fraser Cain: Shortly after Nicole told you –
Pamela Gay: I called you.
Fraser Cain: – you called me, and I think Phil called me as well. There were all of these phone calls going back and forth as we were notifying each other. Jason Major let me know as well, so it was the same thing.
I know you live two hours into the future, and I was just about ready to go to bed as well, and yeah, and then my phone was going off. So much for sleep; time to go to work. We had to sit down in front of the computer and get reporting, and get updating, and figuring out what was going on.
Pamela Gay: Well, and the first question all of us had was this was the same day that an asteroid was scheduled to make a very close approach, passing much closer than the moon, in fact, passing closer than geosynchronous satellites to the plant earth, and so there was the, “Wait, was there another object that’s related?”
Of course, that was the first thing, and everyone’s trying to figure out from the dashboard cams, and where the sun is, and all of that, what the directionality of the impact was, and people fairly quickly realized, “No, completely unrelated object, completely different orbit, coming from a completely different direction. We’re good.”
That was the neat thing, was how quickly we were able to start estimating what direction in the sky it came from by looking at the – it was early in the morning, could see the sun, had geographic landmarks, dashboard cams, street signs, streetlight cameras, and could watch the bink, bink, bink, bink, as it goes all across the city.
Fraser Cain: That’s how you bink. Paint a picture. If you were living in Russia, which you have done, –
Pamela Gay: I have.
Fraser Cain: – and you were driving to work in the morning, –
Pamela Gay: I wouldn’t have done that.
Fraser Cain: – what did they see?
Pamela Gay: These poor sods who were up early in the morning fighting with traffic were minding their own business when all of a sudden, something brighter than the sun was went streaking across the sky and then went kablooey and caused a giant flash.
This was in a good sized city, but kind of in the middle of nowhere, Russia, so out near the Ural Mountains. This was a factory city. That’s got to be somewhat freaky when you live in a country that, like the US, grew up under the fear of the Cold War.
You have all of these people suddenly see a bright thing across the sky kablooey. The problem was that as it went through the sky, it was initially going faster than the speed of sound, so there was the shockwave of the explosion, and the sonic boom that traveled much slower than the speed of light, so you see move, move, move kablooey flash, and then pause, and then you get hit with the shockwave of the sonic boom.
Now, for the drivers, they got to see the entire process, or catch it out of the mirror or something like that, but to the poor souls who were still eating their breakfast or in a classroom or something else, nature had it out for them because this is a Russian city. They didn’t exactly use shatterproof glass to build your average apartment window.
People see giant flash, that’s the type of things that causes you to get up from the table and walk to the window and go, “Huh,” and about the time they’re getting to the window, the shockwave hits, and it pretty much shattered $33 million worth of glass in the city of Chelyabinsk.
Fraser Cain: Can you imagine? It’s exactly right. You’d be in bed, you’d be at the kitchen table, whatever, and then suddenly, your entire room would be lit up as if it was daylight.
First thing, you’re like, “That’s it. That’s the bomb. It’s the end of the world. Here comes Armageddon,” but you would probably walk over to the window to sort of figure out what it was that had gone on, you’d look up, and you’d see this big plume in the sky, and you’re like, “Huh, what is going on?” Then, seconds later –
Pamela Gay: That was one of the awesome things, is I speak very bad Russian, but it was enough that I could understand a fair amount of what was going on in the YouTube videos.
You have these drivers. They’re like, “Huh, that’s odd,” or, “That’s weird,” and they say it in a completely matter of a fact voice, very, “Well, it’s another day. There’s a flash in the sky. Gonna keep going. No big deal.”
No one’s pulling over, no panic. People with cell phone cameras, you see them like, “Oh, must get a better shot,” but that’s the Instagram mentality, not the, “The world is ending,” mentality. I just love that characteristic that’s so different from what you’d get in the United States.
Fraser Cain: Right, and so you just imagine those poor people, they’re walking over, they’re staring at this big cloud in the sky, and they’re trying to figure this out. This is silent, just completely silent. Then –
Pamela Gay: After the kablooey, there’s just this beautiful con trail through the sky that’s starting to get all squiggly as the wind moves it around, and then –
Fraser Cain: Yeah, and then, boom, this shockwave roars through and just explodes the window in everyone’s faces. Was it 1500 people went to the hospital with glass – glass injuries so severe that they had to go to the hospital. You can imagine, again, these are tough Russians who just took a plate glass window in the face.
Pamela Gay: Wearing winter clothing.
Fraser Cain: Yeah, in the wintertime, yeah, in Russia.
Pamela Gay: It’s one of those things that nature had it out for them. It was the perfect setup for a really painful joke. It was a Three Stooges episode, and we were one of the stooges.
Fraser Cain: Amazingly, nobody died.
Pamela Gay: No one died, yeah.
Fraser Cain: Nobody died. A Tunguska-level event happened over Russia, and nobody died, which is just amazing.
Pamela Gay: To put some perspective on the initial impactor, the thing that initially entered our atmosphere, burned up, got smaller as it went through the atmosphere, the object, when it started to enter the atmosphere is estimated to have been about the same mass as the Eiffel Tower. The chunk that they eventually were able to pull out, is the largest piece that landed in a lake, was still over 1000 pounds.
Fraser Cain: Really? I didn’t know they pulled up a chunk that big.
Pamela Gay: Yeah. Unfortunately, they set it on the scales to weigh it, and it tipped over the scales. Literally, it tipped the scales, and when it hit this thing that it survived through the atmosphere, broke into three pieces.
Fraser Cain: Wow.
Pamela Gay: Yeah.
Fraser Cain: We’ve got this on the morning of February – it was 15th, right?
Pamela Gay: 15th.
Fraser Cain: Yeah, February 15th, this object came from space, detonated in the upper atmosphere. How high up did it explode?
Pamela Gay: We think that it probably exploded in the air at an altitude of about 97000 feet, or 18.4 miles, or 30 kilometers, so this was about three times higher than your average commercial airliner flies at on the long haul flights.
It was high up in the atmosphere when it exploded. That actually had one very neat consequence of it scattered shards over a huge area of land, and it was Russia in winter in the Ural Mountains.
This is a snowy place, and so there’s lots of really neat stories of school children basically going out and looking at the surface of the snow for holes in the snow, and then digging down where the hole in the know was to find the meteor shards.
As someone who grew up in the East Coast, that’s how you can find clams, is you look for the air hole in the water, and then you dig down, and there’s a clam. Well, they used essentially the look for the hole in the snow.
If this had happened in summer, first of all, there would have been a lot more injuries because people wouldn’t have been dressed as solidly, and I’m sure people, with the flying glass, got, in many cases protect by their heavy winter clothing, but you wouldn’t have been able to find nearly as many chunks of it because it would have just been harder if it hit dry land rather than penetrating through nice white snow.
Fraser Cain: Yeah, you think about that right now. There are probably meteorites all around you whenever you are. You just can’t recognize them because they just look like rocks.
Pamela Gay: Exactly. Some meteorites, we don’t think about this, but one of the really great posters I saw one year because from collecting meteorite fragments, and then they were comparing them to the size of rabbit turds in photographs.
The meteorites were smaller than the little rabbit balls of poo, and that was the most fascinating thing to see in a science poster. There are small pieces of the universe all around you, and they’re very hard to find.
Fraser Cain: Okay, so we’ve got this object, mass of the Eiffel Tower. How big was it then?
Pamela Gay: We think that this it was probably about 20 meters across, initially, and, of course, it got smaller as it came down. It burnt up, so in some cases, you have, as it passes through the atmosphere, the heat is literally melting the outer parts of it.
It eventually exploded into small fragments, and those pieces when the all over the place. In one case, it destroyed the roof of a factory building, so roughly a 600 square meter roof went flat, no more roof, and this happened in winter. One of the biggest issues they had to deal with – this is all a lesson in all the things that can go wrong.
This is a city that has central heating for the entire city, so they’re pumping hot steam, hot water, to all the buildings, and with all these windows blown out, you’ve had, with the freezing weather, pumps with pipes freezing.
We’ve had problems with pipes freezing here. Well, now you’re looking at an entire city that shares the same heating system, thousands of windows blown out. The city got behind replacing all of the windows that went into people’s apartments. They didn’t replace balcony windows that might have –
Fraser Cain: To their [inaudible] [00:15:06]
Pamela Gay: – gotten broken. It was a level of damage that we hadn’t encountered, but it could have been so much worse.
Fraser Cain: Right, and so this is where I was gonna go next, which was that you looked at Tunguska, and it was about the same sized object, wasn’t it? Maybe Tunguska was a little bigger.
Pamela Gay: It was a completely different type of event. There’s a lot of people that think that Tunguska was probably a comet, or at least a more volatile rich object that came down because when it exploded, it leveled a massive area of Siberian forest. It’s really that the universe has it out in particular –
Fraser Cain: For Russia.
Pamela Gay: – for Russia. When the Tunguska event occurred, there was this massive shockwave that flattened forests, and we didn’t see that kind of a shockwave with the Chelyabinsk event.
Now, the thing with the Chelyabinsk is it was basically a lumpy rock. This was a kind of rare kind of lumpy rock called an LL chondrite. This means that it was low on metals, it was low on iron, and this combination means that you’re basically looking at the type of material that the crust of the earth is made of.
It had a lot of silicas, what metal it did have, and it was ferrous oxides. Everything’s formed together into, well, this is where the name comes from, chondrules of material that the minerals are bound together. It’s not a metallic object, it’s a mineral of stuff that’s all mixed together, and this lumpy chondrules of mineral in this big old rock is perfectly happy to fall apart, which gives us all of these different shards of meteorite.
Had this been an iron-rich asteroid, that wouldn’t have fallen apart in the atmosphere quite the same way. Had this been a comet or something else that was extremely volatile-rich, the process of having all those gases sublimate would have caused a different kind of shock.
Since it was a nice, friendly, low-metal, low-iron chondrite rock, this was about as low a harm event as we really could have S-BGD for, given its size. It also didn’t come straight down.
Fraser Cain: Right, that was my next question I was gonna ask, is what was the impact angle. How did it come in?
Pamela Gay: Well, so, swept across Russia nice, long, slow, at angle of impact. If you look at one of the images of it, it spent a long time in the upper atmosphere. A long that it spent in the upper atmosphere meant that it got slowed down a lot by the atmosphere. It’s when stuff comes straight down and you don’t have these nice, gentle impact angles that you end up with the energy not getting given off in the atmosphere, but instead, it’s able to plow much more deeply into the earth, and that’s bad.
Fraser Cain: Yeah, there’s some wonderful simulations that I’ve seen of the Tunguska impact, and it’s this plume of energy that just came straight down like a hammer, and that’s what flattened all the forest out from this impact zone, while with the Chelyabinsk, it was this low, skimming impact, which I think was, again, was – we were really protected by the composition of the object and the impact angle.
Pamela Gay: It still, all of this said, gave off 20 to 30 times the amount of energy of the nuclear bomb that exploded in Hiroshima, so it was a lot of energy, but it was a lot of energy given off in a long distance through our atmosphere, rather than all of the impact. The explosion occurred up above airplane flying altitudes, and then it was just chunks.
One of the really neat things that I read was the majority of the pieces were gravelly sized, and as they came down, they hit their terminal velocity, so since they were traveling at their personal terminal velocity, it was the same as dropping a piece of gravel off of a skyscraper. Sure, it’s going fast, but it’s not going as fast as that 1000 pound block that luckily fell into a lake. That was going at about 60 to 70 percent the speed of sound.
Fraser Cain: Right, right. The rest of that raining rock down on everybody was not quite as damages.
Pamela Gay: Right.
Fraser Cain: Yeah, it’s interesting. Was it shedding material as it was – it detonated and was one big chunk that just kept going, or was that chunk ablating as it went through the atmosphere?
Pamela Gay: It’s one of those things that we’re probably gonna be telling that story for a long time. People are gonna have to go out, map out the full distribution of where all the meteor chunks were.
There were a couple of unconfirmed, unfollowed up on reports of chunks that fell much further East of the main event, where if they’re to be believes, and I don’t think they are since no one followed up on and it’s been a year, but if they were to be believed, there might have been some chunks that were given off in earlier eruptions than the final explosion, essentially, that left behind this one giant piece.
Fraser Cain: On that day, the next day, all of humanity came together to seriously assess the asteroid threat and build a fleet of space missions that imaged all of the asteroids to tremendous detail and sent out teams of astronauts to start pushing astronauts into safe orbits to protect us from this terrible future.
Pamela Gay: No. In the year since then, we have seen cuts pretty much globally for the funding for astronomy, which means that coming up with ways to deter the threat, coming up with ways to discover these, is going to get harder and harder in the future.
Fraser Cain: People got really busy. There where is a lot of attention within a week, and I know our friends from the B612 foundation and a lot of other people were asked to speak and provide their expert advice, and –
Pamela Gay: Planetary Resources.
Fraser Cain: Planetary Resources, yeah, and to share what kind of a threat this is. There were conversations on the hill, and then let’s take an axe to all the funding.
Pamela Gay: It’s one of those things that kind of amazes me because when it comes to our fear of terrorism, there seems to be no amount of money that they’re unwilling to spend in order to try and prevent nail clippers from going on to airplanes.
Fraser Cain: Yeah. What about the war that the universe has started on us? Why aren’t we funding against this war against the universe because it start it, it’s throwing rocks at us. We need to fight back.
Pamela Gay: This is one of those things that leaves me somewhat baffled, but it is what it is. I can only ask that every time they increase the amount of imaging technology used on me and my baggage when we fly, they spend the same amount of money on imaging technology to protect us from rocks from space.
Fraser Cain: Now, there’s a few things in the works, though, like WISE just came back online, and it is searching – it’s searching for –
Pamela Gay: Infrared.
Fraser Cain: – infrared objects, which asteroids definitely are in that category, and then there’s the work on the NEOCam, which is gonna be another potential mission. There’s the Sentinel mission, which is what the B612 foundation is working on. There’s stuff the Planetary Resources is doing.
Pamela Gay: The Large Synoptic Survey Telescope.
Fraser Cain: Right, so there are a bunch of missions that are in the works, but we didn’t see a rise in funding. We didn’t see any extra energy put into these things. If anything, the overall budgets have been cut back.
Pamela Gay: Right, so it’s within of those things where I can’t explain it. All I can do is sigh into my microphone.
Fraser Cain: Right, we heard it. It was a sigh heard around the world. What’s next, then? I mean, they’re going be studying this rock for years, for decades. I mean, it’s great. They got a huge chunk of space delivered to study.
Pamela Gay: Well, and what I also love is the entrepreneurial spirit that came up, is almost immediately, chunks of the Chelyabinsk meteor were available. You’re looking for yourself. I stupidly left –
Fraser Cain: I am, I am, yeah, look for it.
Pamela Gay: Mine’s unfortunately in my office on campus where I can share it with students and go, “Here, it’s cool.” Thank you, Richard Drum. There, yes.
Fraser Cain: Here’s a rock. This isn’t Chelyabinsk, though, this is – can I buy one?
Pamela Gay: You actually have one sitting on my desk that I don’t trust customs with that Richard Drum got for you.
Fraser Cain: Richard Drum got me a chunk of the Chelyabinsk meteor and it’s waiting on your desk? Why have I only just discovered this now?
Pamela Gay: Because I thought I told you, and apparently I forgot.
Fraser Cain: That is so cool. Richard Drum, thank you so much. I love you. Okay, that is so great. Richard Drum is the person that got me into meteorite fandom in the first place, so the fact that he’s just continuing this habit is great.
Pamela Gay: He is the awesome individual that keeps our YouTube channel going and does all the audio editing for 365 Days of Astronomy, so when you donate to 365, you’re helping me pay Richard to be awesome.
Fraser Cain: How much does a piece of the Chelyabinsk meteor cost?
Pamela Gay: I don’t know; ask the internets.
Fraser Cain: Okay. Internet, how much does it cost? I’ll look it up on eBay. Of course you can buy them on eBay. That’s amazing. Okay, so, people are gonna be studying these for years, right?
Pamela Gay: Yes, and this is one of the cases where I suspect that people are just going be going out with metal detectors. That’s the awesome thing, is even though it was a low metallicity, low iron meteorite, it is still more metal-rich than your average piece of, say, granite.
This means that the way they were able to find that giant chunk in the bottom of the lake, is – well, initially, they actually sent in February in Russia emergency dive teams down to look for it, and when they looked at the bottom of the lake, they found nada.
That summer, a science team went down, surveyed the bottom of the lake using metal detectors, identified a large object using the metal detectors, and it had buried itself in the mud at the bottom of the lake.
That really makes sense. If you’ve ever walked around in a lake, it does not have a completely solid bottom, and if something’s gonna hit at a fairly significant fraction of the speed of sound, it’s not just gonna rest tidily on the bottom.
They dug it up, brought it to the surface, tipped over the scales with it, broke it into three pieces, but the way they found it was with the metal detector. People are going be going out with metal detectors collecting pieces, mapping out the distribution, figuring out just how far and wide were these things scattered.
Fraser Cain: When will we see another one of these? How often will an object of this sort of size, and mass, and damage hit the planet?
Pamela Gay: This is one of those things that we talked about some last week. We can’t fully answer that question because we haven’t fully mapped all of the size of object. There’s an entire class of asteroids, the Apollo asteroids, that have earth-crossing orbits, and it’s just a matter of time before one of these orbits causes us and one of these Apollo asteroids to be in the same place at the same time.
When that happens, things go kablooey or bink, depending on what noise you choose to attribute to it. We’re now looking at, we’ve seen Chelyabinsk, we’ve seen Tunguska. Every 100 years or so.
We don’t know, though. We previously have been saying this was every few hundred years. The bigger things, we’re still looking at being every few million years, hundreds of millions of years, depending on how big you wanna look. We’re also overdue for one of those.
Fraser Cain: Yeah, I know. 65 million years ago, the last one hit, right? It’s time.
Pamela Gay: Yeah.
Fraser Cain: Universe.
Pamela Gay: Yeah.
Fraser Cain: Alright, well, thanks a lot, Pamela. It was amazing to experience this whole story unfold with you and the rest of the space community.
We all had a chance to watch this whole thing unfold in a time of the internet, and is it was quite an experience. I hope it turns into the wakeup call that we know it should be for the law makers and the funding agencies to try and get some of these things mapped out and searched out, and that would be great.
Pamela Gay: Yeah. I really think the idea of, it sounds lame, but it’s a fairly reasonable argument. Let’s spend the same amount of money looking for the things that the universe is doing to try and kill us that we use to try and find ways to identify other people who are trying to kill us.
That would just be – I mean, imagine if we spent the same amount of money on astronomy and space science that we spend on TSA, that we spend on border patrol, that we spend on the FBI, on the CIA, all those organizations involved in protecting us from death. Let’s look for death from the skies.
Fraser Cain: Together, we can defeat the universe.
Pamela Gay: Yes, yes we can.
Fraser Cain: Alright, I think that’s a T-shirt. Alright, thanks, Pamela. We’ll see you next week.
Pamela Gay: Thank you. Okay, bye.
Fraser Cain: Thanks for listening to Astronomy Cast, a non-profit resource provided by Astrosphere New Media Association, Fraser Cain, and Dr. Pamela Gay.
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Duration: 32 minutes