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Unlocking the Mystery of Exoplanet Magnetic Fields | Space Nuts 348 · Space Nuts: Astronomy Insights & Cosmic Discoveries

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Hello, thanks for joining us on Space Nuts, where we talk astronomy and
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space science every week. My name is Andrew Dunkley, your host, and
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it's so glad you can join us. Coming up today, we'll be talking
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about magnetic fields and do they exist on exo planets. We'll also be talking
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about something quite extraordinary, the flattest explosion ever observed in space and it was
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big too, and sad news about Virgin orbit. We'll also be answering audience
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questions about sending high speed satellites into the Solar System and the density of gas.
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That's all coming up on this edition of Space Nuts and rad Internel nine
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Magnian sequenced Space Nuts three two one Space Nuts actually boyd at Bill good and
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joining us to talk Turkey again this week, the Turkey constellation that is Professor
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Fred Watson, Astronomer at Large. Hello, Fred, good day, Andrew
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m Yeah, turkeys are yes. There isn't a Turkey constellations that there should
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be, really sure, I'm sure there's some cluster out there that looks Turkey
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like. Well, actually for most constellations it doesn't have to look anything like
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his name is anyways, take your peek. No, Well, the country
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of Turkey could use a bit of a at the moment, they're a pretty
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rough time of it. Why not the Turkey constellation that's two of Keio.
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Now, yes that's true, you're right, Yes, yes, absolutely,
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hey Bane, Oh well thank you. Yeah, I'm still pushing back the
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frontier as well, not from which the frontiers of knowledge, as the frontiers
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of bureaucracy. Yes, there's a lot of that. Yeah. We had
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had a nice event last week when a virtual reality movie of the site in
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Western Australia where the radio Murchis and radio telescope is or where the squakulometer array
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will be a virtual reality movie of all that, showing you what it's like
2:15
there and what kind of landscape it is. That was launched at the National
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Museum of Australia in Canberra on Tuesday nights. I think it was which I
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gave a little talk about astronomy and all the other stuff, and one of
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my colleagues at Chenko, who was specialist working with the SKA, he also
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gave a talk and then we had this view of the virtual reality tour,
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which is astonishing. It's my first real experience with decent stereo glasses of a
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virtual reality movie and yeah, you've got three hundred and sixty degree view.
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You turn your head around and you see behind you. We did that at
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Easter. Nothing to do with astronomy, but there's an escape room in Dabo
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which is very popular and they've they've brought in a virtual reality experience. So
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I did that with my boys at Easter too. That's the first time I've
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ever done it too. It's it's a bizarre thing, but it's a lot
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of fun. It's a heck of a lot of fun. Yeah, yeah,
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And this is a fantastic production as well. It's really well done.
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It will certainly be circulating more in Australia maybe globally. Some of our obviously
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listeners might find it coming up. It's called Beyond the Milky Way. Okay,
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it's the title of it. Sounds good. All right, let's talk
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about what we came together to talk about today, amongst other things. I
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mean, we don't always stay on track. Occasionally we might drift just occasionally.
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I wouldn't be like us would not at all really, but we know
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about Earth's magnetic field and how important it is to or basically protect us from
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all the evils of the universe and to keep our atmosphere intact. So the
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question has been raised, do you find magnetic fields on exo planets? Now?
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This is a very important question because obviously, if we're looking for life
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out there, we probably need to find a planet that has a rocky surface
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with probably water or something similar, and it would have to have a magnetic
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field, would it not? But yes, it probably would be an important
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component because, exactly as you've said, the Earth magnetic field protects the atmosphere.
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It also protects the surface from the more energetic subatomic particles that are floating
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around in space, many of which are launched from the Sun with its solar
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wind and occasional solar flares. We are largely protected, not entirely, but
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largely protected from the effects of those things on the Earth surface by the oars
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On magnetic field. Yeah. So yes, the question is do rocky exoplanets
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have magnetic fields? Now? I have to say that I would assume that
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the answer to that is probably yes, because planets tend to be made in
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the same way no matter where in the universe they are, and rocky planets
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probably usually have, like the Earth does, a core made of iron and
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nickel, and that is what generates the magnetic field. It acts like a
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dynamo and generates the magnetic fields as the Earth rotage. So you'd think that
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the answer would probably yes, but yes to the question of do rocky planets
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around other stars have magnetic fields? And so, observations have been made with
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the Carl G. Jansky Very Large Rate, very large array, which is
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a telescope and a ray telescope in the United States, one of the biggest
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in the world. Actually I've visited it. It's quite an extraordinary place operated
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by the US National Science Foundations National Radio Astronomy Observatory, and so observations have
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been made by scientists of a star called why zed Setti, which is a
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star that actually emits radio signals. Now not all stars do, but this
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one does. And the what the what the scientists have done is used the
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radio signals coming from this star, which is about twelve light years away,
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so it's a it's a close star to interpret what is happening to its planet.
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Because we know that why zed Setti, I should say why z Seti?
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Shouldn't I? Just for our American listeners, that's the one yes,
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is why is it set B is a known planet orbiting the star, and
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what has been observed are sort of bursts of radio waves which are to do
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with the interaction between the star's magnetic field and the planet going around it.
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Now, the good thing about this planet is it goes around once in two
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days, so it's very close to its parent style and that means that there
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are probably, you know, magnetic interactions taking place between them if the planet
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has a magnetic field. So, to cut the long story short, these
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bursts of radio emission have been analyzed and and there is enough evidence that they
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are that the scientists in question are convinced that what they've proved is that the
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planet whized Setti B has its own magnetic field. So there are a number
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of different a number of different scientists involved with this, including the director of
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the National Radio Astronomy Observatory and astronomers from buck Mel University and the University of
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Colorado. So quite a disparate group of principally US scientists who have been looking
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at this, and some very nice quotes from those scientists, one of them
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who says, I'm seeing this thing that no one has seen happen before,
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which is always a nice thing when you're working astronomer and you're sitting at a
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big telescope somewhere and something turns up. We saw the initial burst and it
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looked beautiful. This is a quote from another of them. When we saw
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it again, it was very indicative that, Okay, maybe we're really they
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have something here. So what they say saying is that as this planet goes
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around its star they have it interacts with the magnetic field of the star in
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such a way that you get you get bursts of radio energy, and so
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in fact, to let me read another quote from one of the scientists,
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what we're doing is looking for a way to see the invisible magnetic fields.
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We're looking for planets that are really close to their stars and a similar in
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size to Earth. These planets are way too close to their stars to be
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some way you could live. But because they're so close to the planet,
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it's kind of plowing through a bunch of stuff coming off the star. And
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that's the equivalent of the solar wind that we have in the Solar System.
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If the planet has a magnetic field and it plows through enough star stuff,
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it will cause the star to emit bright radio waves and that's they are interpreting
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these these bursts as being In fact, they've they've kind of coined a new
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phrase, which is really nice extra solar space weather, space weather beyond the
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Solar System. So when we think of space weather, we think of the
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environment of the Earth principally, but the subatomic particles within within the inner Solar
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System that comes from the Sun and space weather. It's actually it's a big
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issue. In fact, I was talking to one of my colleagues in the
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Space Agency yesterday about exactly this. How you how you deal with space weather?
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Yeah, in a in a probably in a legislative fashion, because that's
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what a lot of the what the Space Agency does. But yeah, you've
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got to make the rules. So how does it work? You know?
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What? What what what's the what's the what's the story with it? Anyway?
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Sorry, go ahead, Yeah, I'm just I don't mean to scrib
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back out of water over the discovery. But should we be surprised that except
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planets probably have magnetic field? I mean, we were surprised when we found
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the first EXB planet, but we always thought they'd be one, and now
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we've found thousands. So it stands to reason that a lot of them would
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have made magnetic fields as well. Yes, and that is certainly true,
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and it's already been established with the bigger ones like the you know, the
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hot jupiters. Yeah, that's being established that they that they do have magnetic
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fields. These things are bigger, brighter, bee fear in every way,
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and so things like that are easier to detect. But the crucial thing about
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this is that this is a rocky planet, an earthlike planet in terms of
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its size, and that's the difference. But you know, as I said
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at the beginning, you might well expect given that if it's a rocky planet
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made like the rocky planets in the Solar System, it will probably have an
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iron core which will give rise to a magnetic field. On the other hand,
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here's a counterargument to that. Andrew Venus doesn't and I that does Mars.
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So there are two rocky planets in our Solar System which are quite new
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by that don't have magnetic fields, and certainly not not magnetic fields today.
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Now Mars is thought to have had a magnetic field, but it's lost its
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magnetism because it's it's too small for that to be sustained by the core of
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the planet, that the planet's cooled down too much. Venis is a different
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kettle of fish though, because it's Earth like, it's almost the same size,
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aren't we Yes, that's right. Yeah, So yeah, if Venus
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doesn't have a magnetic field, then it's not not a foregone conclusion that any
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rocky planet is going to have a magnetic field. So that's the issue.
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Now, there is one twist to this story that I found fascinating, and
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that is that magnetic fields when you've combine them with a solar wind, and
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that's what we're talking about with space weather, that's what produces the rory on
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the Earth, the northern and southern lights, the Aurora Borealis, the Aurora
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Australia. When we see them on the guest giants too, don't we do?
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Yeah, all that, all the guest giants have rory as well.
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Now these now rory can be detected in radio waves as well as visible light.
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That's the crucial thing. So you can you can know about rory from
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radio astronomy. And it turns out that this YB. Cetti's system has rory,
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but what they're actually seeing is rory on the star. Yeah. Wow.
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Interactions between the magnetic field and the and the wind of particles coming off
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cause magnetic disturbances which they can identify as being due to Rory, even though
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we can't see them. But they also think that if the planet has its
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own atmosphere, and that's certainly not something that's known, if it did,
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that would also have rory. Quite incredible. Yeah, that's that. That's
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another thing. Rory could be a very common thing in the universe too,
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sounding like it, Yes, Yeah, that's right. Wow, that's that's
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quite a discovery. So I didn't tip water on them. I just I
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know you didn't brought up an angle that created more information more information. That's
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that's correct. Yeah, right, It's always good to to be skeptical of
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these things. I'm an optimist when it comes to historiomy. Indeed, actually
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I'm an optimist when it comes to pretty well everything up to say, which
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really annoys some people. Well yes, but they're pessimists. But if you
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want to chase up this story, you can go to one of our favorite
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websites and read up on it. Fizz dot org. Phy s by the
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way, is dot org. This is space Nuts. Andrew Ungle here with
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Professor Fred Watson, great space nuts. Now, Fred, this one fascinates
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me because this is only a fairly recent discovery in terms of what we're talking
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about, only dates back to I think twenty eighteen when they first spotted one
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of these. Um they're called an f BOT FBOT, and basically we're describing
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a cataclysmic explosion in space. But they're different from an explosion as we know
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it now. Most explosions sort of go out in all directions simultaneously. This
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one didn't, and they've just discovered another one, and it's one of the
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biggest or flattest explosions ever observed. Yes, such, right, So,
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yeah, the f BOT, an f BOT in this instance is a fast
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blue optical transient. Yeah, it could. It could also it could also
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stand for a fantastically big optical telescope. It could do it, but it
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doesn't. It's a fast blue optical transient and so that kind of tells you
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about it. Its optical, so he sees invisible light. It's blue because
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that's the wavelength range, the blue wavelength range that it emits its lighting.
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It's fast because it comes and goes very quickly. And transient just is referring
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to the fact that it is something that is not permanent, it's tempering,
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transient in its nature. This is a star in another galaxy, a galaxy
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about one hundred and eighty million light years away, so it's not part of
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our local group of galaxies, which goes out to about five of ten million
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light years, perhaps a few more. But this is an explosion of a
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star that has some there's some difference from what we normally see. Normally when
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you see an exploding star Andrew, as you well know, is it's a
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supernova. Yeah, it's a star that's got to the end of its life,
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run out of hydrogen, run out of everything it needs to burn in
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a normal ways. Yeah, it didn't paste tolls all of that, and
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you know, everything has come to an end and it collapses and in the
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process of the collapse you get this huge emission of energy as it winds up
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becoming or it's called becomes a neutron star or perhaps a black hole. Yeah,
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but this is something different and it's and it is, I have to
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say, not clear how these f bots work. Scientists and this study has
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been done mostly by British scientists, don't really know what causes fast blue optical
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transit, but they can observe them. And this particular one has been observed
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with a smallish telescope. And it's actually one I know quite well because whilst
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it's not the one at Siding Spring Observatory, which is called the Last Cumbers
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two meter telescope, this is called the Liverpool Telescopes. It's Liverpool Telescope.
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It's a two meter diameter telescope and it was made by a sort of corporation
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in Liverpool in the United Kingdom. In fact, they made about five of
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them. I think one came to our observatory here in Australia, one went
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to the island of Maui in the Hawaiian Chain, and one called the Liverpool
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Telescope is actually on La Palma in the Canary Islands. That's an island again
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that hosts large telescopes on one of its volcanic peaks. I used to work
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there a lot during the nineteen nineties. So the Liverpool telescope has a piece
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of equipment on it which is specialized in the world of astronomy, but very
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very powerful in terms of what it can tell you. And I'm kind of
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friendly with scientists here in the University of New South Wales who use similar equipment.
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These are called polar emitters, and they measure polarization, not just the
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brightness of light or its color, that's to say, it's wavelength. They
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also measure whether or not it is polarized and whether what the amount of that
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polarization is. And we kind of know about polarization from polarizing sunglasses. The
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idea being that the vibrations of light waves in when the light is polarized,
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they sit in one particular plane, or sometimes they are taste actually, which
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is more complicated, but but it's essentially that the equipment that's on the Liverpool
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telescope is the equivalent of a pair of polarizing sunglasses, so that as you
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rotate them you see different intensities. In the case of polarizing sunglasses, it's
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to kill the right reflections coming off a road or a bright surface, which
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you can do by blocking out that that polarization of the lights. Yeah,
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so you can do something similar in astronomy. And now polarization is caused by
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principally emission from dusty particles, things that have got an alignment to them that
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they're that that they're you know, perhaps shaped like a pencil or something like
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that. And if you've got lots and lots of particles of duster aligned,
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for example, by magnetic fields, you can work out from the polization where
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those magnetic fields go. I'm not explaining this very well, but it lets
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you determine some structure in a you know, a source of radiation that you
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wouldn't otherwise be able to see. And that's how just by looking at the
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light that's come from this f bot, these scientists can tell that there is
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a flat disc of material around it, as you said, the size of
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the solar system, which is the result of the explosion. Something has exploded,
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and it's exploded not in a spherical fashion light we expect everything to do,
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including supernovae. It's produced a flat disk of material and that is a
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is a mystery. How how how does first of all, how do these
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things work? And secondly how does it create this flat There's a scientist.
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The lead author of this study was actually in Sheffield in the North of England.
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University of Sheffield's Department the Physics and Astronomy, doctor Justin maun says very
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little is known about FBOT explosions. They just don't behave like exploding stars should.
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They're too bright and they evolve too quickly. But simply they are weird.
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If this new observation makes them even weirder, there's a little bit more,
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perhaps I can read from doctor Maund. Hopefully this new finding will help
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us shed a bit more light on them. We never thought that explosions could
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be this a spherical There are a few potential explanations for it. The stars
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involved may have created a disc just before they died, or they could be
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failed supernovers where the core of the star collapses to a black hole or neutron
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star, which then eats the rest of the star. What we now know
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for sure is that the levels of asymmetry recorded are a key part of understanding
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these mysterious explosions, and it challenges our preconceptions of how stars might explode in
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the universe. We never thought that they'd go off bang a flat, so
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yours think of everything that explodes in the universe is going out in all directions
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simultaneous phies spherically, Yes, may I ask, and I don't presume to
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be sort of again tipping water on their observations and discoveries, But could it
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be we're only seeing part of the explosion and that there is in fact a
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spherical outburst and we just can't see parts of it, or are they pretty
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certain this is a dead flat type of explosion. That's a really interesting comment,
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Andrew, well done, and you should write to these people and tell
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them that, because there are things in the universe where we think we're seeing
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something, but what's really happening is that we're not seeing the whole picture.
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And often it's a dust cloud or something like that that is blocking our view
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of what's what's what else is there? If I could put it that way,
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so it's possible, you know, you could imagine that something like a
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dust cloud could be blocking our view on always seeing is that isn't the flattened
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exploding disc. I think what knocks that on the head fair enough, and
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so maybe you shouldn't write the right to them is that the way they've detected
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this is by polarization. And I suspect if it was just a spherical explosion
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and part of it was being blocked off, we wouldn't have that phenomenon.
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It wouldn't be the light wouldn't be polarized. So it's something to do with
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the actual structure of this disc of material that gives you the polarization, and
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that is telling you that it really is a flattened disc of stuff, that
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this star is emitted rather than rather than blocked off view of something more symmetrical.
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Yeah, and the other interesting thing is that, like many things we
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have talked about recently, this is a fairly new discovery. As I said
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at the start, the very first one of these was only discovered in twenty
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eighteen. So yes, this is this is a whole new realm that we're
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again trying to understand. It's right up there with the dark matter and dark
25:12
energy and even black holes. We don't really understand a lot about them.
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This is another one. Yeah, that's right. And of course that's the
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great thing about astronomy. When something new like this comes up. He sends
25:25
the theoreticians back to the drawing boards, scrutching their heads. How can we
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account for this? How can we explain what's going on here? So push
25:33
his physics along as well to try and understand what what actually is happening.
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Yes, indeed, okay, that's on the dot org website as well.
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But if you want to do some deeper reading about it and read five hundred
25:45
pages of authors to the Monthly Notices of the Royal Astronomical Society. That's where
25:51
you'll find the paper on f bots. This is based nuts Andrew Dunkly here
25:56
with Professor Fred Watson being with a job space nets if it before we go
26:04
to questions this this is a story that came as quite a surprise to me.
26:10
And this is only a recent announcement but has some bad news for Virgin
26:15
Orbit. Yes, that's right. So Virgin Orbit, which is you know,
26:19
a spin off really from Virgin Galactic and you remember there their stock in
26:25
trade is the launch of orbital vehicles using a converted bowing seven four seven ye
26:32
to carry a rocket up to forty thousand feet or thereabouts, where upon the
26:36
rockets dropped and it ignites and off it goes to launch payloads into orbit.
26:41
It's it's got marvelous advantages actually because you can do launches at short notice,
26:48
you can launch from anywhere. Basically you don't have to be you know,
26:52
on a continent. And you would have thought that that would have that would
26:56
have been very commercially attractive and would have you know, naturally resulted in a
27:03
company at least staying viable and probably doing very well. But what seems to
27:11
have happened is that because of SpaceX now being able to essentially bring down the
27:21
cost of launched by actually recovering their launch vehicles and using them again. We've
27:26
talked about this many times, the fact that SpaceX's Falcon nines can be used
27:30
up to about twenty times now and that's brought the price down, and the
27:37
suspicion is that that has made Virgin or a bit less competitive. Plus they
27:42
had sadly their last launch didn't work. We covered it. Actually it was
27:51
earlier this year where the rocket, I think the second stage failed because of
27:57
a filter that was blocked. This was a launch made from southwest Britain from
28:06
the aircraft took off and launched over off the shore of Cornwall. So yeah,
28:15
unfortunately the satellites that were launched didn't make it. They didn't make the
28:21
second stage because of that filter issue. And so that's that's very sad and
28:26
that might kind of be the final straw that's caused this company out of file
28:33
for bankruptcy. Very sad Virgin Orbit. It's very sad, especially for us
28:37
in Australia, because I think the next launch was planned to take place from
28:42
the one of the airfields in Queensland into Womba. Remember were planning to launch
28:48
from there. Yeah, it would have been very exciting for the for the
28:51
city. Torn is a beautiful place it is, and yeah, it's it's
28:56
a real pity. This doesn't have any impact on Virgin Galactic at all though,
29:00
does it not? As far as we knew? I mean, Virgin
29:03
Galactic's gone quiet at the moment after I think the first flight sh if I
29:08
remember, and I can't remember those that was last year when Brunson flew on
29:14
the rocket plane. But we're still wasting for playing passengers to be launched up
29:18
there. Yeah, all right, they'll probably be more on this down the
29:22
track. Yeah, okay, Fred, let's get to some questions. Got
29:26
a couple of text questions today, Hey, Fred, and Andrew, longtime
29:29
listener, first time caller, and I was wondering why we haven't seen or
29:34
heard of more exploratory missions where we send a satellite at extremely high velocity out
29:41
towards objects in the Solar System or perhaps beyond. Given the rapid advances in
29:45
technology, is it feasible to do fast sites in space. I assume the
29:51
fastest man made object is also called is also space related, and any idea
29:59
what the fast a man made object is and the implications of high relative velocities
30:04
in space and the impact it has on said object in the data that we're
30:08
able to collect. Being expanse fans, I recall a character racing around the
30:15
Solar System and being a gearhead myself, this topic is near and tear.
30:22
So yeah, that's from Michael in North Dakota, far North Dakota. He
30:26
makes a point of saying, so, yeah, look, we've done a
30:32
few missions out there, and of course you think of the voyager probes which
30:34
are still going even though they're having to shut things down bit by bit to
30:38
keep them alive. But yeah, why haven't we done more? Why can't
30:42
we, with the current technology just go boom, send something out at super
30:47
high speed and do some exploring. Yeah. So, yeah, the technology
30:56
is, it is advanced, but you're still limited by the physics of you
31:03
know, the chemistry of rocket propulsion and the physics behind it. So the
31:08
fastest launch I think I'm right in saying this was New Horizons, Yeah,
31:15
which had to be quickly boosted to a velocity that would take it past Jupiter
31:25
so that it got a sling shot out to Pluto. It was launched in
31:30
two thousand and six, it rolled flu by Pluto in twenty fifteen, and
31:34
it's now escaping the Solar System. It's had its rendezvous with arikof that strange
31:44
little double asteroid that was in the headlines the beginning of the year before last,
31:49
I boost track of these things. It might have been the year before
31:52
that, I think twenty twenty one. I think it was. Yeah,
31:56
So that's the nearest thing to, you know, to what Michael suggesting,
32:00
and that really pushed the technology to get new horizons up to that high initial
32:06
launch speed. I suspect he's right that the fastest human made object is a
32:13
spacecraft. I'm trying to think of terrestrial experiments. The Helius satellites, apparently,
32:20
the first two satellites designed to study the Sun, traveled at one hundred
32:23
and fifty seven thousand and seventy eight miles per hour. There, I'm told
32:29
they're the fastest ever man made objects in space. Okay, and the most
32:34
object on Earth. You're going to laugh this. This was during a nuclear
32:38
bomb test called operation plumbob and Robert Brownlee was asked to design the test and
32:46
he put a he put a cover over the test point of the test tube,
32:55
if you like, and he wanted to test the speed of the the
33:00
manhole cover when the explosion happened, and I don't know exactly how he did
33:05
it, but it came out. It got blown into the into the stratosphere
33:09
at one hundred and twenty five thousand miles an hour. So that's the fastest
33:14
Earth based man made object as far as I can tell. That's just a
33:17
quick search I've done. And I think one of the fastest objects that carried
33:23
a person in space was Apollo ten, a Polo ten capsule at twenty four
33:30
thousand, seven h ninety one miles an hour. That's quick, yes,
33:37
Um, I never think in miles an hour, Andrew, No, I
33:40
just I'm trying to be rapidly converting these to kilometers per second. Yeah.
33:45
So that last one's about eleven I think, which is actually the escape velocity
33:50
of um so, uh yeah, the of the money cover. That's a
33:57
that's a great story. The fastest, the fastest spacecraft as we speak today,
34:05
however, is Voyager one, which you mentioned earlier, which is still
34:09
traveling away from the Sun. It's just under seventeen kilometers per second, and
34:15
that's that's the you know, in terms of something that's ongoing. That's the
34:22
fastest human made object. It's moving away at that speed, and you know,
34:29
we'll keep going forever probably pretty well until it's something yes or not.
34:36
It's more likely to go into orbit around something, yeah, you know,
34:39
if it winds up in a foreign solar system. On the other hand,
34:45
it could fly through a solar system a bit like baffle any sentient beings that
34:52
that are out there. But anyway it can get caught in the orbit of
34:55
another planet, because we we've had that happen here with Earth. We had
35:00
a second moon there for a little while. It might still be yes,
35:05
that's right, tiny little so so. Yeah, so Voyager one certainly holds
35:10
the record at the moment that's being the fastest spacecraft flying. If it was
35:16
on its way to Proxima Centauri, it would get that in seventy four thousand
35:21
years. Yeah, So that cost start that kind of makes the high speed
35:27
technology of today is still fairly redundant in terms of long haul space travel.
35:31
Unfortunately, indeed, it does okay, Thank you, Michael. Let us
35:36
move on to our next question from another Michael, who calls himself Mike.
35:40
He's from Brisbane. Space nutters. The density of gas in the vacuum of
35:46
space. We're always talking about and looking at gas clouds in space, and
35:51
a question is what is the density of gas in between the planets of the
35:54
Solar System? What is the density of gas in between the stars and the
35:59
galaxy? And what is the density of gas between galaxies? Also, what
36:01
is the density of gas in a typical nebula. I'm assuming the answer will
36:07
be x number of adams per cubic meter, with X being a small number.
36:12
Regards Mike, it's a good question. It's good and Mike's given the
36:16
answer as well, so it is it's a small number of atoms per cubic
36:22
meter. Um kind of feeling that when I wrote Space War, I wasn't
36:30
no, was it cosmic Chronica. I think I talked about this stuff right
36:35
at the beginning. I can't remember, said he reaching for one of his
36:37
own books. Yeah, it might be. It might be easy to because
36:44
I've talked about I talked about, you know, finding itself in typical place
36:52
in space. Oh yeah, before and the answer is if it's dark and
37:00
it's cold, and it's empty and somewhere I thought i'd given how many atoms
37:08
per cute Here we are if you're lucky, all right, this is in
37:13
This is in normal it's in a typical a typical location, so it's between
37:20
the galaxies. It's not in a solar system. This is in the depths
37:22
of space. If you're lucky, you might find one atom of hydrogen in
37:27
the volume of space normally taken up by fifteen adults a cubic meter. Wow,
37:32
so what that's that's typical, you know, or typical of the intergalactic
37:38
space one atom per cubic meter. And it goes up from there with I
37:46
guess you know. The nearer you are. If you're in the intergalact interstellar
37:52
medium in our galaxy, it's significantly higher. It's probably measured in tens of
37:58
atoms per cubic meter. The solar environment is rather more populated. It's probably
38:06
hundreds of attempts but qubic meter. But it's still a vacuum to all intents
38:09
and purposes. Yeah, I'd have to look up the numbers, and I'm
38:13
sure Mike is as capable as I am of doing that to find the you
38:17
know, density of of of the the things to look up at interstellar,
38:23
medium, solar wind, those sorts of places. That's where you want to
38:27
find the numbers, the exact numbers. But it is small, it's tiny.
38:30
If you would talk about one of those beautiful nebula, like the Horsehead
38:36
nebula or something, what be the density and something like that, it's still
38:39
still extremely low. So you could find through it, you could fly through
38:43
it. Absolutely, yeah, it's it's it's very low. Um that just
38:52
there's an adjumpt to that little story in the history of astronomy. And it
38:59
kind of straits how though, these nebular densities are, because when nebulae were
39:04
first observed with the spectroscope by a man called William Huggins back in London in
39:08
the eighteen sixties, he found emission and you know, it's the kind of
39:16
optical fingerprint of gases that we used to work out what's in space. He
39:22
found he found these what would call emission lines, this fingerprint of some gas
39:27
that was completely unknown on Earth, and they actually called it nibullium because they
39:32
thought they didn't they'd discovered a new element. That was in the eighteen sixties,
39:37
and nibullium was one of the huge mysteries throughout the latter days of the
39:42
nineteenth century into the first couple of decades of the twentieth century, because he
39:49
got to be an even bigger mystery because by then the periodic table had been
39:52
invented and there were no gaps where there could be a nebulium thing. And
39:57
it was a man called Ira Bowen, who was an American astronomer later became
40:01
the director of Lick Observatory, if I remember rightly, who worked out what
40:07
it was that He'd had some hints by some comments by another astronomer before him,
40:13
but he figured out that what we were seeing was emission from a normal
40:20
gas but a very very low pressure where the atoms don't bump into each other
40:25
at all, which is what you get in the nebula. Yeah, there's
40:30
hardly any bumping of together of atoms. Its coffee money everyone thing. Yeah,
40:42
Andrew carn't talk to you view it all right, we're nearly done.
40:51
Yeah, so so it's just a you know. It was that was when
40:54
they recognized that this was nearly a vacuum and this. The atoms are so
41:00
far apart they don't interact, and that gives you this difference signature for what
41:06
is an otherwise normal gas. In fact, that those spectrum lines are called
41:10
forbidden lines because they're forbidden on Earth, right, but they're not in the
41:15
dets for space. Fascinating. I want a poem about it, called forbidden
41:22
Lines. Maybe I should read it one day. Maybe should? Maybe you
41:24
should? Yeah, Okay, there you go, Mica. I'm sure you're
41:29
glad you asked the question of age. You knew the answer by the sound
41:31
of it, Yes, very good. I don't forget. If you do
41:35
want to send us a question, you can go to our website space nats
41:38
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41:43
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space science. You can learn about supporting Space Nuts by becoming a patron.
42:10
It's all on our website Space Nuts podcast dot com. Fred. That brings
42:16
us to the end of another episode. Thank you so much, sir.
42:21
It's a pleasure and I'm sure we'll do it again sometime. I reckon we
42:24
will sometimes soon, I hope, yeah, maybe, yeah, Okay,
42:30
take care, we'll talk to you in sounds. Great. Thanks Andrew,
42:32
Fred Watson an astronomer a large part of the team here at Space Nuts Central.
42:37
I'll call it that from now on. And thanks to you on the
42:40
studio for what I don't know, but thanks anyway, and from me Andrew
42:44
Dudley, thanks for your company. Looking forward to joining you again on the
42:47
next episode of Space Nuts. Bye bye. You'll be listening to this Space
42:53
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