#399: Celestial Collisions & the Art of Extinguishing Stars: Probing Planetary Impacts and Fire Safety in Orbit

[00:00:00] Hi there, thanks for joining us. This is Space Nuts. I'm your host Andrew Dunkley, always good to have your company.

[00:00:07] Coming up on this episode we will be looking at fire and space. Not usually two things you want to put together, although stars are technically fire in space but we're talking about fires on space ships.

[00:00:20] You don't want that but NASA has been looking into it and a glowing space cloud could be a clue to an ancient planetary collision.

[00:00:29] We'll look at those things on this week's episode of Space Nuts.

[00:00:50] And joining me again is Professor Fred Watson astronomer at large to look at all of that. Hello Fred. I'm Andrew.

[00:00:57] I was it going in your lack of the woods. It's been hot and muggy with we've had all sorts of we've had just about every season there is over the last few weeks.

[00:01:08] It just ever changing. I think we've got that tug of war between seasons where summer's saying I'm not letting go yet. I want my piece of the pie so it goes backwards and forwards.

[00:01:22] Some days are very, very hot. Some days are very, very mild but yeah, I think autumn will fall into line soon.

[00:01:32] This is why this is why a lot of different First Nations peoples in Australia have more than four seasons because of the exact for that.

[00:01:43] Yeah, yeah. I mean we've basically created four seasons but it doesn't really glean that way a lot of time does it?

[00:01:53] Not when you shoot. What would you call extra ones?

[00:01:56] There's many different Aboriginal names for us. Marvelous extra seasons. That's a very interesting stuff. Yeah, it is. I'm going to have to read up on that.

[00:02:07] Fred, let's get down to business and we're going to be talking about fire and space and of course fire does insist in space in the form of well stars.

[00:02:19] But that's a natural phenomenon. We're talking about unnatural man made fires on spaceships and rockets and there have been some famous cases since the space race again began.

[00:02:33] I suppose the most infamous of them was the fire in the capsule of Apollo one an oxygen issue, I believe.

[00:02:41] But there was another one that I read about that I didn't know existed and that was on the mere space station back in 1997.

[00:02:51] They had a fire that threatened the space station and the crew fire in space just doesn't work well together at all, doesn't it?

[00:03:01] I'm going to step back in it because we're going to get listen a question, listen a comments about this if I don't stars stars are not on fire.

[00:03:12] Oh, you know, they're out at least he's a fire is no there are flames.

[00:03:18] It's just a very, very hot object so fire technically needs oxygen and you know a lot of people a lot of people do say that what how can the sun burn when there's no oxygen in space but

[00:03:29] it's not burning and just a ball of gas that's heated by nuclear fusion but it's not on fire.

[00:03:36] Somebody would somebody would have come in they are now they would yeah I know.

[00:03:42] But to cut to the chase the kind of fire that you're talking about in the inside of spacecraft yes is not good news.

[00:03:51] And so it's it has been the purpose of a series of experiments run by NASA they're called sapphire I'm not sure it could be safe fire as well because it's a fa double FSA double F I R E.

[00:04:07] So say fire might be a better way of saying it but the sapphire has been actually it's a six phase experiment each of which has had 19 runs of fire.

[00:04:20] Where they've tested you know the basically the flame properties of lots and lots of different materials including plexiglass.

[00:04:34] What we call perspex cotton no mechs and something called solid inflamed inflammatory boundary at low speed fabrics there you go a class of fabrics that are obviously there to stop to stop fire spreading.

[00:04:51] And so what they've done is they've had this unit which is about three feet by four feet in which they test these various materials by setting them on fire with the camera inside and it's actually a windtower.

[00:05:09] So the vehicle in which these experiments are carried out which is not the international space station you'll be glad to hear it's one of the the signals vehicles that is used to supply the international space station.

[00:05:23] And in fact it's usually on the way back where this signals where these vehicles going to burn up in the atmosphere anyway so they run the tests then and basically they they this unit is a wind tunnel.

[00:05:37] So it's got it's got an airflow through it and you can change the you know proportion of oxygen in the air and things like that change temperature change all the various factors and look at the heat release rate that's coming from them and you know workout what might happen if such a fire occurred actually in a space vehicle.

[00:06:01] And so this is the last one that was that was conducted just a few days ago during one of the returns of a signal supply vehicle but what an interesting thing to do to use what resources you have to basically to in the long term enhance mission safety.

[00:06:22] And essentially feed that back into the designs and you're absolutely right you know that everybody has in the space industries has got echoes of the Apollo one fire which was when Apollo had a pure oxygen atmosphere and that's what basically put a stop to that that is more.

[00:06:41] Yeah absolutely.

[00:06:43] Yeah and and it changed safety protocols there after on several levels but yeah pure oxygen and caused the pressure to rise to 29 PSI which ruptured the command modules in a war.

[00:07:00] Flames and gases then rushed outside and the command module through an open panel and yeah the rest is history it caught them completely off guard they couldn't get out.

[00:07:12] Terrible terrible tragedy but there was also a fire on the mere space station in February 1997 there was a crew six onboard at the time.

[00:07:24] And they were in quite a deal of peril when it fired not it and again it was oxygen an oxygen generating system the flames lasted several minutes which they managed to one get under control I think.

[00:07:43] I don't know exactly how they got out of that one but I think they cut off access to the so is the skate vehicles are they couldn't get off yeah very perilous situation indeed yeah and I guess just to illustrate how how much thing things have changed

[00:08:03] by the fact that we now understand controlling fire much better in a spacecraft the Tiangong space station which is the Chinese space station back in September to astronauts on board the Tiangong station during a live broadcast from the space station they lit a candle.

[00:08:29] And so you know that's that's really just to demonstrate the you know that things have got much safer now than when they were I'm not sure how long they let it burn for either blowing out very quickly.

[00:08:43] Yeah indeed but yeah they're less a candle.

[00:08:47] Yeah actually I'd be resistant to blowing it out because yeah that's right you've got to blow flame on to something in a zero G environment yeah yeah so you pinch it and that will be the way yeah I'm sure that would be the way to do you know what your fingers and yeah that's right test yeah.

[00:09:06] I think I remember in the movie the Martian they portrayed a an issue with fire when he was trying to create create water for his potato farm while he was stranded on the on the red planet and used a can't remember the name of the system but.

[00:09:25] He blew himself up the first attempt because he didn't allow for the oxygen he was exhaling in the calculations and balance the fuel on the burn yeah so the extra oxygen created an unstable environment so when he basically fired the spark to get the whole system going the whole room exploded.

[00:09:48] Yeah and yeah it was actually very cleverly explained I don't know if it would really happen that way probably but yeah I don't suppose it's so easy to forget that when you're breathing you do actually you actually it's higher oxygen because it's not all over itself in the trouble.

[00:10:07] Yeah so the solution is just to keep doing tests and to keep trying to come up with ways of reducing the effect of fire because inevitably there will be fires in space I dare say yeah that's right.

[00:10:23] There will be times where accidents will happen you can't say it will never ever happen and in the confines of a spaceship and that was with the media space station I said there was a crew of six it was actually a change over period.

[00:10:36] Usually it takes and usually has three crew but they were doing a change over which made it even more complicated under those circumstances but and apparently the toxic smoke got into the into the systems that create their oxygen and it was pretty pretty hairy.

[00:10:55] I and you got nowhere to run I mean in space you can't run outside and wait in the street for the fire brigade you just you got to figure it out is so do you do I imagine the training Fred that they go through for run as astronauts and cosmonauts and all the other countries that are sending people into space these days.

[00:11:17] You would spend hours and hours and days and weeks and months looking at all possibilities you know cementing it in your brain as to how to deal with these situations.

[00:11:29] I'm sure that's right I mean you know we know what you know what kind of training aviation pilots go through and to me every possible circumstance actually even when you know Marty was doing a flight attendant training.

[00:11:46] That's that's incredibly intense it's all about the safety and reacting to situations and things of that sort.

[00:11:54] You do months and months of training and learn how to make a coffee on the last day or something like that you know because everybody thinks it's still been coffee but aviation generally has similar similar kind of protocols but in space exactly as you've said they're carried too much greater extreme so the training of an astronaut would be very very significant.

[00:12:15] Indeed a wood and you know when we were growing up being an astronaut was every child's dream and well every boy's dream probably but it's not exclusive to to males these days of course and that's rightly so but the astronauts were few and far between and cosmonauts.

[00:12:37] These days you could probably pass a few in the street and been done the wiser it's becoming a more common job now.

[00:12:46] Yeah something like I haven't looked at the numbers recently it's well over 500 it's probably six maybe even 700 people who've actually been into space now it's a lot larger number yeah.

[00:13:00] And I think it's going to keep on growing and at a reach of point probably in the next 50 hundred years maybe where it's some you know people are living and working in space for long periods of time space station space tourism.

[00:13:13] I think it's got to happen that way ultimately and I wonder I wonder who will be the first baby born in so far that's definitely going to happen yeah.

[00:13:26] So all of this learning about fire in space is feeding directly into all sure that's right it gives us you know confidence that we can cope with these things.

[00:13:37] Coming up with new safety protocols and new materials that are far retardant new extinguishing systems I'll just keep working on it yes fascinating.

[00:13:46] And if you'd like to check out that story it's on the Fizz dot org website this is space nuts and redunkly here with professor Fred Watson.

[00:13:57] Spice nuts now Fred to our next story which is a bit of a mystery but it looks like observations have come up with reasoning for this but we're talking about a star that was bright and then it wasn't and they sort of looked at the data and went hang on a minute something difference happened here.

[00:14:23] And we're talking about an eclipse that lasted 500 years in this case for five so obviously 500 days 500 days sorry to say yes 500 days so what the these space scientists had to be very patient to figure this one out that's right although I understand it and do this.

[00:14:46] This discovery has been made largely from what we call archival data data that I can buy you know by a telescope system of some sort of which is archived it's freely available to the astronomical community that's how the radio bus were discovered by scientists trawling through archival data from the parks radio telescope here up in Northern Western New South Wales Marillain.

[00:15:14] The telescoping question in this case was something called wise which is a something like the wide angle infrared survey experiment I can't remember the exact acronym but wise was a spacecraft that as far as I know is now no longer operational but was run by NASA and it's as the name implies it's an infrared survey telescope.

[00:15:44] But what's happened is a large group of scientists actually I think most of them are based in in Lydon in the Netherlands and they're led by somebody I've worked with actually a guy called Matt Kenworthy so it was really nice to see his name on the paper which is in nature magazine so that's a top line journal to have this published in the papers entitled a planetary collision afterglow and transit of the resultant debris cloud.

[00:16:12] So that gives you the story but in you know in gobbledygook science speak so what what they've what they've done here is taken observe data on it's actually a sunlight star but much much younger than our sun it's only about 300 million years old and so we probably is surrounded by you know

[00:16:39] the prototype plan of your disc or something like that so young planets are being formed and we know that in the in the suns within the first few hundred million years of the sun's history everything was banging to everything else so Mars sorry how the moon was formed it's probably how Uranus fell over all of these things are the results and we think of collisions in the early history of the universe

[00:17:04] and so looking at a star that is going through a similar period can be very instructive and sure enough when they did look through these data they found stuff that is very instructive in in other words evidence of two young planets colliding and their big ones too by the sound of it from what they from the analysis.

[00:17:27] So what happened to it it it basically the star was very bright in its infrared luminosity because it's an infrared telescope so it brightened up over a period of a thousand days but there was to start with the spike in in its in this increase in brightness.

[00:17:54] So what happens is the star behaving normally suddenly it's brightness increases with a spike but the brightness remains high even though there was an initial spike and it actually lasted for about a thousand days but about why are sort of you know something like I guess two thirds of the way into that there's was suddenly a dimming of the star.

[00:18:24] And that caused a dip in brightness which itself lasted for 500 days so it is a sort of dip over overlapping this brightness in luminosity and what they think has happened here is well the the the the the put this all down to glowing glowing cloud of gas and dust and dust is but some infrared wavelengths dust is very luminous because it's warm.

[00:18:52] And some the longer wavelength infrared is heat radiation so they what they think was that to newly formed planets and one of which they had the detail that it may have contained ice and that's by the analysis of the infrared spectrum that you're looking at this gas cloud anyway these two giant planets somewhere

[00:19:17] they're probably bigger than earth maybe multiple earth masses crashing to one another and that creates a glow because of the heat released but then essentially produces what they think would be a molten core surrounded by a large cloud of gas and rock and dust the debris from the collision.

[00:19:40] And that sort of continues to orbit the star and eventually it moves in front of the star and darkens it so that's how they've got both the brightening of the star and a dimming of the star.

[00:19:55] Now I think there was a ground based survey that picked first picked up this star but the data must the data have come from the wise mission as I mentioned.

[00:20:10] I might just read a little bit from the abstract of the paper itself because it just gives a few more details and so this is that nature paper I mentioned, I can't worry at all planets grow in rotating disks of dust and gas around forming star some of which can subsequently collide in giant impacts after the gas component is removed from the disk.

[00:20:36] And so did I did here we report combined observations of the young about 300 million years old solar like star a s a double SN dash 22 q j an infrared brightening consistent with a black body temperature of 1000 degrees Kelvin that's absolute zero and luminous luminosity that is 4% of that of the star lasting for about 1000 days.

[00:21:05] Partly overlapping in time with a complex and deep wavelength dependent optical eclipse that lasted for about 500 days.

[00:21:14] And so they say the optical eclipse started 2.5 years after the infrared brightening implying an orbital period of at least that duration what's all what they're saying is it's going to have more than a 2.5 year year of our own years.

[00:21:31] Yeah and then they say the observations are consistent with a collision between two exoplanets of several tens several to tens of earth masses at 2 to 16 astronomical units from the center of the star member in the restaurant unit is the distance of the Earth from the song such an impact produces a hot highly extended post impact remnant with sufficient luminosity to explain the infrared observations transit of the impact debris across the disk of the star sheared by orbital motion into a long cloud.

[00:22:00] Causes the subsequent complex equips eclipse of the host star I can't read anymore but what a great summary of a really interesting observation something that's you know it's like many of these things it's a hypothesis unexpected.

[00:22:17] Yeah now I did find the what wise stood for wide field infrared survey explorer okay so the name of that down the explorer room.

[00:22:31] Yeah you're pretty close and what what's going to happen now I mean they think there's two planets basically smashed into each other and cause this heat and cloud so then what happens next will they fuse together.

[00:22:46] They're all will they create moons or well that's a good point yeah there might be months so it sounds as though the core of this newly created planet which is still molten we think is in orbit around the star but the as they say that the debris disk has been stretched out probably into something

[00:23:08] Bernala shaped transit of the impact debris sheared by orbital motion into a long cloud causes the subsequent complex equip eclipse of the host star so that you know that long cloud of debris could itself

[00:23:22] coalesce into smaller objects maybe moons if they gravitationally bound to the to the remnant caused by the collision so yeah it's kind of watched this space we need probably 10 to 20 or 30 million years to see what's really going on but it's definitely going to be worth keeping an eye on.

[00:23:43] Yeah I was going to say we probably have to be very very patient to always transpire.

[00:23:51] Could could maybe some of that do debris cause a ring?

[00:23:56] A really good suggestion yeah there's a good chance of that as well you're on the lanydair and you're firing it all cylinders will all of them.

[00:24:03] I got off to a slow start but I'm making a comeback.

[00:24:09] It's it's I fascinated by the fact that they can figure all this out from historical data that yeah what sort of a distance are we talking about from Earth do we know how far this is what we do but I can't remember what that was actually let's see how do we got a distance?

[00:24:28] Yes because it just it's another astounding thing that they can take historical observations from something it's obviously not anywhere within our vicinity.

[00:24:40] Yeah and put to get put together a I don't know a sequence of events that they think occurred I think that's incredible science.

[00:24:53] Yes that's and it is the best of astronomy really you know we astronomy generally needs needs well it will be lovely if we go on touch things and do experiments on them but we can't.

[00:25:08] So it always needs radiation or particles that are transferred across the void between us to actually work out what's going on.

[00:25:20] I'm just trying to find its distance from what we know it is 1,850 light years away there you are and it's a constellation of purpose.

[00:25:35] Oh okay the poop yeah we're moving on.

[00:25:40] Boom boom now I'm kidding.

[00:25:42] The space do you know I don't get it yet.

[00:25:47] You walked into it but I did yeah I'm usually careful.

[00:25:50] Puppies translates as the poop but usually I say it's a poop deck because it's one of the three constellations the giant ancient constellation of Argo now this the ship Argo was broken up into purpose, Vila and Karina

[00:26:06] and Puppies is the poop deck but it's yeah it's the part I want to say if you've got a bunch of school kids in front of you.

[00:26:15] Yeah don't go down that rate it reminds me many many years ago when I had to go to a school in Muggie and they had a few guest speakers and I was invited to go along to talk about radio.

[00:26:26] And I told them about a time where I was on air and I opened the microphone and I could just feel a little something and I thought I'll just deal with that before I start talking.

[00:26:37] It was a bit louder than I expected and there was this.

[00:26:42] Went to air the kids love that story.

[00:26:47] Well, but it's true it happened of course I had to try to keep a straight face because it was just a fraction of a second before I started talking and yeah and you're listening to you did.

[00:27:01] Anyway, it makes a good yarn when you're doing guest speaking gigs.

[00:27:05] I wondered where it was yes it would I wondered where it was in your career where you lost all credibility because I've had pretty much.

[00:27:14] Pretty much then.

[00:27:17] It's certainly broke the ice at that little key on a so that story is available at the NASA website science.nasa.gov if you want to check it out.

[00:27:29] Fred, that brings us to the end of this particular show and people are going here in a minute what about the Q&A yes there's Q&A but we've decided to do them as two separate shows.

[00:27:40] We've been experimenting with it recently so never fear you will get the second part or the new episode of Space Nuts Q&A on Mondays so yeah we're doing two versions mainly due to listen to feedback because people want a more run by sized.

[00:27:58] Version of the show so we're going to split it into two shows for the benefit and of course you can still listen to the whole thing lock stock and barrel if you wish through.

[00:28:11] Patreon but yes in general terms we're going to be doing two shows a week but you'll still get the whole thing as as you used to just in two parts.

[00:28:22] So Fred thank you so much and we will catch up with you on the next episode of Space Nuts.

[00:28:29] It's very good to talk Andrew thank you very much.

[00:28:35] See you soon Fred Watson astronomer large and thanks to you in the studio.

[00:28:41] Let me see.

[00:28:43] No it's not here okay and for me Andrew don't we see you on the next episode of Space Nuts bye bye.

[00:29:11] you