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Cosmic Questions, Solar Mysteries & Lunar Dreams: #492 - The Great Space Q&A · Space Nuts: Astronomy Insights & Cosmic Discoveries

• 0:00
  Speaker 1: By there, Andrew Dunkley here and you're listening to Space
• 0:03
  Speaker 1: Nuts Q and a edition. Glad to have your company
• 0:07
  Speaker 1: once again. On this episode we will be answering an
• 0:12
  Speaker 1: array of questions on very different topics. Jake is asking
• 0:16
  Speaker 1: us about tidle Locke. That's not something to hold back
• 0:20
  Speaker 1: the water in the Thames River, No, something completely different.
• 0:25
  Speaker 1: Clint wants to talk about the heat of the sun. Emily,
• 0:29
  Speaker 1: Sandy's daughter in Melbourne, wants to get to the moon
• 0:33
  Speaker 1: and we're going to tell her how. And Fenton has
• 0:36
  Speaker 1: asked a vast array of questions which could probably fill
• 0:40
  Speaker 1: an episode on their own about the radiation of Jupiter.
• 0:44
  Speaker 1: That's all coming up on this edition.
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  Speaker 2: Of Space Nuts Channel ten nine ignition Space Nuts or
• 0:56
  Speaker 2: three two one spaces and I reported Neil's good and.
• 1:04
  Speaker 1: Joining me once again is not Professor Fred Watson because
• 1:07
  Speaker 1: he is overseas looking at the sky up in the
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  Speaker 1: Northern Hemisphere. But with us is Professor John D. Horner,
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  Speaker 1: Professor of astrophysics at the University of Southern Queensland. Johnty, Hello, Hey,
• 1:19
  Speaker 1: how are you going? I am well, we're working on
• 1:21
  Speaker 1: getting you your own intro, but we're in a time
• 1:25
  Speaker 1: of year where all the radio stations in Australia want
• 1:29
  Speaker 1: new jingles, and our studio producer who does all that
• 1:34
  Speaker 1: work is flat out at the moment, so we've been
• 1:37
  Speaker 1: put on the back burner, I think. But you can
• 1:39
  Speaker 1: understand why all the radio stations want to ramp up
• 1:42
  Speaker 1: how they sound so that they can get new audience.
• 1:45
  Speaker 1: I worked in radio for forty years. I'm pretty sure
• 1:47
  Speaker 1: changing the jingle doesn't actually do much, but just my
• 1:52
  Speaker 1: observation in forty you'll look at it just in time
• 1:56
  Speaker 1: for Fred to get buck. Yes, yes, I think that's
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  Speaker 1: exactly what I was about to say.
• 2:00
  Speaker 3: Stole my joke.
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  Speaker 1: Never mind, But what we'll do right now is look
• 2:07
  Speaker 1: at some audience questions. I love this particular episode every
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  Speaker 1: week because it's the audience's chance to get involved. And
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  Speaker 1: we've got a few audio questions coming up. But our
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  Speaker 1: first one comes from Jake, who actually sent this question
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  Speaker 1: via Facebook Messenger, which we don't often catch because we
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  Speaker 1: don't monitor it as much as we as we probably should.
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  Speaker 1: But we just haven't got the person power. But I
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  Speaker 1: just happen to be sort of on my iPad the
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  Speaker 1: other day and went, oh, hang on a minute, there's
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  Speaker 1: a little one there. Greetings from Tennessee, USA, Tennessee, home
• 2:44
  Speaker 1: of the Titans.
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  Speaker 3: I know that.
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  Speaker 1: Several two body systems are in various stages of tidal locking.
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  Speaker 1: I was wondering if for star or planet with several
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  Speaker 1: orbiting bodies can even become tidally locked with a particular one.
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  Speaker 1: For example, can the Sun become tidally locked to one
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  Speaker 1: of our planets? Likewise, can Jupiter become tidally locked to
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  Speaker 1: one of its moons? I assume that if such tidal
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  Speaker 1: lock can occur, the larger body becomes locked with its
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  Speaker 1: most gravitationally attractive orbiting body. But if that's the case,
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  Speaker 1: how are the other orbiting bodies affected? Love the show
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  Speaker 1: And that was a question from Jake Tyler. I've got
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  Speaker 1: a feeling that he's going to some of the things
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  Speaker 1: he said in the question are the reality.
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  Speaker 3: Yes, So there's a lot of complete sit to this.
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  Speaker 3: It's a really really good question. Now we're familiar with
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  Speaker 3: tidal locking. Anytime we look up at the annoying source
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  Speaker 3: of light pollution in our scar that is the moon,
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  Speaker 3: you know, keeps one face pointed towards us all the time,
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  Speaker 3: with a little bit of rock and roll because it's
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  Speaker 3: been nudged by everything else. It's not on a perfectly
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  Speaker 3: circular orbit, but it essentially keeps the nest out of
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  Speaker 3: the moon festus towards the far side, festers away. It rotates.
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  Speaker 3: One something SUTs this and exactly the same time it
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  Speaker 3: takes to go around the Earth, essentially, so it's turning
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  Speaker 3: as it goes. The Earth is slowing down in its
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  Speaker 3: rotation as the Moon is getting nudged away. There's this
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  Speaker 3: tidal interaction between them that I always visualize essentially as
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  Speaker 3: being the result of the tidal bulges. The Moon res
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  Speaker 3: is on the Earth, so we get high tid and
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  Speaker 3: a low tide every day, and I view those a
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  Speaker 3: bit like break blocks on a wheel. They're kind of
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  Speaker 3: applying friction to the Earth because the Earth is turning
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  Speaker 3: under them once every twenty four hours or so, but
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  Speaker 3: those tidal bulges are doing one lap every twenty seven
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  Speaker 3: twenty eight days because they are tied to the location
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  Speaker 3: of the Moon and the Sun. So those bulges are
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  Speaker 3: drugged along by the friction of the Earth. They're pulled
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  Speaker 3: slightly away from that line between the Moon and the Sun,
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  Speaker 3: which means that they are then pulling a little bit
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  Speaker 3: on the Moon and causing the Moon to speed up,
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  Speaker 3: which means it moves away. They've got this transfer of
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  Speaker 3: energy and momentum between the rotation of the Earth and
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  Speaker 3: the orbit of the Moon, so the Earth's spin is
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  Speaker 3: slowing down and the Moon is moving further away. Now,
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  Speaker 3: in theory, if we could carry on full long enough,
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  Speaker 3: that would eventually slow the Earth rotation down such that
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  Speaker 3: it matched the orbital period of the Moon. There is
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  Speaker 3: some debate though, a that will not happen quick enough
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  Speaker 3: for it to happen within the age of the Solar
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  Speaker 3: System that's left. But there's also some debate as to
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  Speaker 3: whether that would happen before the Moon gets far enough
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  Speaker 3: away to escape the Earth gravity. So in the case
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  Speaker 3: of the Earth Moon system, it's not going to happen,
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  Speaker 3: but it illustrates that it could so move out further
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  Speaker 3: out of the Solar System to Pluto, the dwarf planet.
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  Speaker 3: And we talked about Pluto a couple of weeks ago
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  Speaker 3: having this big companion called Charon. Yeah, Pluto actually though
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  Speaker 3: has about five minutes. It's got Charen, which is huge,
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  Speaker 3: and then it's got four little ones in Kerberos, knicks, sticks,
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  Speaker 3: and hydra I think they're called, and then smaller ones
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  Speaker 3: further out. Now Pluto and Caron are tidly locked. Karen
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  Speaker 3: spins once in the time it takes to all bit
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  Speaker 3: the center of mass between Pluto and Karen once, so
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  Speaker 3: it always keeps the same side facing towards Pluto in
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  Speaker 3: just the same way that the Moon does going around
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  Speaker 3: the Earth. But Pluto has also tidally locked with Charon,
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  Speaker 3: so Pluto keeps the same face pointing towards Karen all
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  Speaker 3: the time. So that's a prime example of the kind
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  Speaker 3: of system Jake was asking about a case where the
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  Speaker 3: biggest body has locked to the second biggest body and
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  Speaker 3: they're both locked together, and there are other things in
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  Speaker 3: the system. When it comes to plantary systems, and when
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  Speaker 3: it comes to the more generality of it, it gets
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  Speaker 3: a bit more complicated. So there's a few things going on.
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  Speaker 3: It's not necessarily the most massive body going around a
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  Speaker 3: star that would be the one that it tidally locked up,
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  Speaker 3: because the distance is important as well, and tidal forces
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  Speaker 3: fall off incredibly rapidly as a function of distance, much
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  Speaker 3: more quickly than the asquad fall off of the gravitational attraction.
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  Speaker 3: I think it's either an arcugorn ark to the power
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  Speaker 3: for setup, which means that the closer you get to
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  Speaker 3: the star, the much more strongly you tidally interact. Now
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  Speaker 3: we see this with exo planets. We can see the
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  Speaker 3: exo planets that are very close to their stars are
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  Speaker 3: tidally locked. The ones that are further away are probably not.
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  Speaker 3: But we also see it in the form of tidal
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  Speaker 3: circularization of orbits. So you get a planet that is
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  Speaker 3: flung onto an elongated orbit where the closest point to
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  Speaker 3: the star is very near the star because of the
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  Speaker 3: degree to which tidal forces vary as a function of distance.
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  Speaker 3: That means a star will interact much more strongly with
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  Speaker 3: the planet in a tidal sense when it's near the
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  Speaker 3: closest approach, and when it's far away. That means that
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  Speaker 3: you will get a you'll get an attempt to tidally
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  Speaker 3: lock the planet, so the planet's rotation will be getting
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  Speaker 3: meedged into a rotation period that matches the overal period.
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  Speaker 3: But at the same time you get this dissipation of
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  Speaker 3: energy that tries to make the orbit more circular, and
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  Speaker 3: that dissipation of energy is happening at the perry apse
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  Speaker 3: of the orbit, the point of the orbit where it's
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  Speaker 3: closest to the star. The result of this is that
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  Speaker 3: that all bit gets more and more circular by bringing
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  Speaker 3: the appo apps the furthest point from the star closer
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  Speaker 3: to the star. So it ends up being circularized at
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  Speaker 3: that closest approach distance, and that happens more quickly than
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  Speaker 3: the tidal locking process. And that's the result of the
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  Speaker 3: fact that the tidal forces fall off much more strongly
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  Speaker 3: as a function of distance. We haven't yet found any
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  Speaker 3: stars that we think are definitely tidally locked to their planet.
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  Speaker 2: Now.
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  Speaker 3: Part of this is down to the mass difference, so
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  Speaker 3: the small thing will tidally lock on much more quickly
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  Speaker 3: than it's bigger companion. That's what we're seeing with the
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  Speaker 3: Earth and the Moon. But it's not beyond the bounds
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  Speaker 3: of possibility. And there are suggestions that tidal interactions between
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  Speaker 3: really massive planets planets a lot bigger than Jupiter, and
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  Speaker 3: stars when the planets are really close in, can have
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  Speaker 3: a significant impact on the spin of those stars and
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  Speaker 3: also the energy dynamics of what's going on in their interiors.
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  Speaker 3: Not totally my area of expertise. I've got a flag that,
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  Speaker 3: but this is something that people have having to think
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  Speaker 3: about when they come to looking at ways of measuring
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  Speaker 3: the age of stars. Now there's a few ways you
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  Speaker 3: can do this. I've got colleagues at UNISQ who work
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  Speaker 3: on astero seismology. They're looking at how stars wobble and wibble,
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  Speaker 3: ringing like bells that have been struck, and you can
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  Speaker 3: look at the different frequencies at which they're wobbling and
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  Speaker 3: wibbling to learn a lot about their interior. And that
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  Speaker 3: kind of study can give you an estimate of the
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  Speaker 3: ages that's really quite accurate, but it's really resource intensive.
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  Speaker 3: You need to stare at a star for a long
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  Speaker 3: time doing a lot of observations. If you're trying to
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  Speaker 3: just get the age of stars in general. There's a
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  Speaker 3: technique called gyro chronology or gyro chronology, which is essentially
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  Speaker 3: measuring the rotation speed of the star and using that
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  Speaker 3: to get a first estimate of its age, which will
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  Speaker 3: have quite big uncertainties, but seems to do a reasonably
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  Speaker 3: good job. And the idea here is that when stars
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  Speaker 3: are bond, they're bond from material collapsing, in which spins
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  Speaker 3: faster and faster. So typically a newly born star will
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  Speaker 3: spin quite quickly every day or two, but over billions
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  Speaker 3: of years, all the masts losing through the stellar wind
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  Speaker 3: what kind of act as a break on the star's rotation,
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  Speaker 3: taking away that angular momentum, causing its spin to slow
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  Speaker 3: down over time. So if you know the degree to
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  Speaker 3: which stars slow down as a function of time, and
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  Speaker 3: you measure how quick a star's spinning, it gives you
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  Speaker 3: an estimate of its age. BECs an old star will
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  Speaker 3: spin slower than a young star, but if that star's
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  Speaker 3: got a really close in planet that's interfering with it tidally,
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  Speaker 3: that will impact that process. Yeah, so there's a lot
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  Speaker 3: of aspects to this. I appreciate I'm going a little
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  Speaker 3: bit off topic from Jake's question, but it shows you
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  Speaker 3: the complexity of it. And it's why it's such a
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  Speaker 3: good question because it's something that we don't know the
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  Speaker 3: final answer to. It's going to depend very much on
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  Speaker 3: each individual system. For the Earth and the Moon, we're
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  Speaker 3: probably never going to get fully tidally locked to the Moon,
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  Speaker 3: but we know that when the dinosaurs walk the Earth,
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  Speaker 3: the Earth was spinning quicker and we've had independent verification
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  Speaker 3: of that. Not only do we know that from the
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  Speaker 3: tidal motion of the Moon moving away, we can measure
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  Speaker 3: the speed of the Moon's moving away, but there are
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  Speaker 3: also measurements that have been made of fossil beds that
• 11:02
  Speaker 3: show that there were about three hundred and eighty three
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  Speaker 3: hundred and ninety days a year back in the Cretaceous. Now,
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  Speaker 3: the soorbital period hasn't changed, as mentioned in the number
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  Speaker 3: of seconds. So how do you get more days in
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  Speaker 3: the year. You get more days in the year by
• 11:15
  Speaker 3: making the days shorter. So that's the direct outcome of
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  Speaker 3: that tidal reaction between the Earth and the Moon. Pluto
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  Speaker 3: is a stage further along that's fully lopto. You've got
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  Speaker 3: an interesting case in our sol system of mercury, which
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  Speaker 3: is trapped in a three to two spin orbit resonance,
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  Speaker 3: so it's tidally locked, but it's not locked in one
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  Speaker 3: to one, and the only reason that works is that
• 11:37
  Speaker 3: mercury is on an elongated orbit and is also not
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  Speaker 3: a perfectly spherical object. Gets quite complicated, yeah, but this
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  Speaker 3: gets odder the more you study it basically, and there's
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  Speaker 3: a lot of depth to it, so it makes it
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  Speaker 3: a fabulous question.
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  Speaker 1: He certainly is. Thank you, Jake. A question popped into
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  Speaker 1: my head while you were talking. You talk about the
• 11:55
  Speaker 1: effect of the moon on Earth's oceans, the tides. Would
• 12:01
  Speaker 1: it be to an too extreme a thought to suggest
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  Speaker 1: that the tides are actually just a slow motion tidal wave.
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  Speaker 3: You could possibly think of that way. I never have
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  Speaker 3: done before, but it's an interesting one because the phrase
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  Speaker 3: tidal wave in itself is quite misleading because they're not
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  Speaker 3: really waves in the same sense as the waves we
• 12:25
  Speaker 3: see on the beach. So this is where when you
• 12:27
  Speaker 3: see disaster movies and you get this enormous toll breaking wave,
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  Speaker 3: that's not really what a tidal waves like. A tidal
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  Speaker 3: wave is a huge body of water rising and falling.
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  Speaker 3: So it's more like the surface of the ocean getting
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  Speaker 3: higher or lower, and it's probably when it gets really
• 12:41
  Speaker 3: close to the coast that that can break. So I
• 12:43
  Speaker 3: know people who are into geophysics and ocean dynamics who
• 12:47
  Speaker 3: get grumpy at disaster movies for getting tidle waves totally
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  Speaker 3: totally wrong. But in that sense, our tides are very
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  Speaker 3: much like that. It's the same kind of process of
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  Speaker 3: water rising and falling and a huge body of a
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  Speaker 3: to doing that means it slushes around a bit as well.
• 13:03
  Speaker 3: Very similar thing and tied into this. Of course, when
• 13:05
  Speaker 3: the moon was closer to us, which it had to
• 13:08
  Speaker 3: be in the past, when the days were shorter, the
• 13:10
  Speaker 3: tides were higher and more extreme, and that's tied into
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  Speaker 3: arguments people have had about the origin of life, suggesting
• 13:17
  Speaker 3: that the origin of life happened in the intertidal region
• 13:20
  Speaker 3: on the car which would have been larger when the
• 13:22
  Speaker 3: tides were higher, but the tides were happening more quickly
• 13:25
  Speaker 3: as well, so the inundation and drying out happened on
• 13:27
  Speaker 3: a quicker time scale. So first ample of the move.
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  Speaker 1: Yeah, it's going, it's intriguing. It's an amazing sign. Thank
• 13:36
  Speaker 1: you again, Jake Gregg. Question glad I happened across it
• 13:39
  Speaker 1: the other day. This is Space Nuts. Andrew Dunkley here
• 13:42
  Speaker 1: with Professor Johnny horn Apps. Okay, we take all for
• 13:49
  Speaker 1: Space Nuts. Let's go to our next question, which comes
• 13:53
  Speaker 1: from Clint.
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  Speaker 4: Hi've Fred, Hi, Andrew, this is Clint from Rome, Georgia
• 13:59
  Speaker 4: US say love the show, Happy New Year. My question though,
• 14:03
  Speaker 4: comes from the Sun. We know the surface of the
• 14:07
  Speaker 4: Sun is around six thousand degrees celsius, but the corona
• 14:10
  Speaker 4: is much hotter millions of degrees. I know scientists are
• 14:14
  Speaker 4: still puzzled with this phenomenon, but my question is, could
• 14:17
  Speaker 4: this be due to the gravitational pullback towards the Sun
• 14:21
  Speaker 4: that is causing some kind of friction on leaving matter
• 14:24
  Speaker 4: that the Sun is losing or projecting. Just a thought
• 14:27
  Speaker 4: I have when reading how the Parker solar probe came
• 14:29
  Speaker 4: its closest to the Sun earlier last year or this year,
• 14:35
  Speaker 4: depending on when you're listening to this, and they use
• 14:40
  Speaker 4: its own gravity to power it quickly through the surface
• 14:44
  Speaker 4: of that corona. Just a quick question I had while
• 14:47
  Speaker 4: exploring that.
• 14:48
  Speaker 1: Thank you, Okay, thanks Clint.
• 14:52
  Speaker 3: Love the accent.
• 14:53
  Speaker 1: Now, I know the Sun isn't your main area, but
• 14:58
  Speaker 1: I'm guessing you've done your homework on question.
• 15:01
  Speaker 3: A little bit. It's actually a real head scratcher because
• 15:03
  Speaker 3: it's pushing the boundaries of what we know, and that's
• 15:05
  Speaker 3: what I really love. So, you know, the first thing
• 15:07
  Speaker 3: for me to say here, and I think it's always
• 15:09
  Speaker 3: important to acknologe it, is that I don't know the
• 15:11
  Speaker 3: answer here. Fully, I'm not an expert. The part of
• 15:14
  Speaker 3: the badia of science is asking questions we don't know
• 15:17
  Speaker 3: the answer to. That's what makes a scientist. If we
• 15:19
  Speaker 3: already knew the answer to everything, it'd be really, really boring.
• 15:22
  Speaker 3: And the Sun's corona, and by extension, the corona of
• 15:25
  Speaker 3: all the stars that we see, is so an ongoing problem.
• 15:29
  Speaker 3: So exactly as you said, the photosphere the visible surface
• 15:32
  Speaker 3: of the sun, that area of the Sun is about
• 15:36
  Speaker 3: eight hundred and six thousand degrees center grade celsius roughly
• 15:41
  Speaker 3: not precise, but it's high density. So that's essentially the
• 15:47
  Speaker 3: final surface you can see before like gets scattered. So
• 15:49
  Speaker 3: the analogy often use here is like looking at a
• 15:51
  Speaker 3: fog bank. A fog bank is not solid, but when
• 15:54
  Speaker 3: you're on a foggy or a mystic day, people measure
• 15:56
  Speaker 3: the distance that you can see, and the denswer the
• 15:59
  Speaker 3: fog is the shorter of that distance. Is of course,
• 16:02
  Speaker 3: you're looking at particles, and essentially the photosphere of the
• 16:05
  Speaker 3: Sun is the last surface of which your average photon
• 16:08
  Speaker 3: of light would hit a particle and be scattered. So
• 16:11
  Speaker 3: once it reaches this point, you can escape space. And
• 16:13
  Speaker 3: so that gives us this illusion of a solid surface,
• 16:16
  Speaker 3: when in fact you just get into a denser piece
• 16:18
  Speaker 3: of gas. So the gas in the photosphere is quite
• 16:21
  Speaker 3: dense and a huge amount of radiation comes out from it.
• 16:24
  Speaker 3: So when people look at the Sun in the sky,
• 16:27
  Speaker 3: and there's always the usual caveat here of please don't
• 16:29
  Speaker 3: do that, because it's a very good way of damaging
• 16:31
  Speaker 3: your eyes permanently. But when you see the Sun, when
• 16:34
  Speaker 3: you see a photograph of the Sun, that surface you're
• 16:37
  Speaker 3: seeing is because there's a high density, so there's a
• 16:39
  Speaker 3: huge amount of radiation coming in coming out of it.
• 16:42
  Speaker 3: When we get in the totally eclips of the Sun,
• 16:44
  Speaker 3: we suddenly see this beautiful diaphanous, very variable area around
• 16:49
  Speaker 3: the Sun we call the corona, and that's a much whiter,
• 16:53
  Speaker 3: bluer light. When you get color photos which is indicative
• 16:56
  Speaker 3: of a much higher temperature, and you think, what, it's
• 16:59
  Speaker 3: a higher temperature. The amount of energy that you get
• 17:03
  Speaker 3: from a photon is related to the temperature, to the
• 17:05
  Speaker 3: power for really incredible more energy. So shouldn't the corona
• 17:10
  Speaker 3: be brighter than the surface of the Sun. Why don't
• 17:12
  Speaker 3: we see it? And the answer is because the individual
• 17:15
  Speaker 3: photons are much more energetic, but there's far, far, far
• 17:19
  Speaker 3: far less gas set, so there's much less flux. You've
• 17:24
  Speaker 3: got higher energy photons, but a lot less of them,
• 17:27
  Speaker 3: so you can only see it when the sun's blocked out.
• 17:29
  Speaker 3: But the corona is incredibly hot. It's like a million
• 17:31
  Speaker 3: two million degrees, this incredibly tenuous gas, hot enough that
• 17:36
  Speaker 3: the individual atoms, the individual nuclei are traveling quick enough
• 17:41
  Speaker 3: that they'll escape the Sun's gravity and flood out into
• 17:43
  Speaker 3: the space. So corona links in with the solar wind,
• 17:46
  Speaker 3: they're connected, and it's been an outstanding, really long term
• 17:51
  Speaker 3: question of how on Earth the corona is heated to
• 17:54
  Speaker 3: those temperatures, What on Earth's going on?
• 17:57
  Speaker 1: Now?
• 17:58
  Speaker 3: The gravity idea, the idea of friction. There will be
• 18:02
  Speaker 3: a little bit of friction, So any particles entering into
• 18:04
  Speaker 3: the corona that are colliding with things will transfer energy
• 18:08
  Speaker 3: to the to the atoms and nuclei that they're impacting,
• 18:12
  Speaker 3: and you can get some degree frictional heating there, but
• 18:14
  Speaker 3: that's going to be a very very very small amount.
• 18:17
  Speaker 3: It's not going to be anywhere near enough to do this,
• 18:19
  Speaker 3: but you're right, it will probably contribute a bit of
• 18:22
  Speaker 3: energy to this. And we know full well that there
• 18:24
  Speaker 3: is continually dust, a material falling into the sun. The
• 18:28
  Speaker 3: most spectacular example of that are the sung graysing commets
• 18:31
  Speaker 3: that go in and fall apart and fragment, dumping a
• 18:35
  Speaker 3: huge amount of dust and gas into that corona in
• 18:37
  Speaker 3: a localized event. Now, the thing that to me, from
• 18:41
  Speaker 3: a science education background, from the way I've been trained
• 18:45
  Speaker 3: to think about problems, to say that Clint's idea doesn't
• 18:50
  Speaker 3: quite work, would be to look at the distribution of
• 18:52
  Speaker 3: temperature in the corona, so the bulk of the mass
• 18:56
  Speaker 3: entry into the corona would be the rarer events like
• 18:58
  Speaker 3: the breakup of sungras in common you get one hundred
• 19:01
  Speaker 3: meter sized object breaking into dust, and that would inject
• 19:03
  Speaker 3: a lot of material in one particular place. So if
• 19:06
  Speaker 3: the mechanism Clint was suggesting was the main one, you'd
• 19:10
  Speaker 3: expect that one bit of the corona to then become
• 19:12
  Speaker 3: much hotter and much brighter than the rest, and we
• 19:15
  Speaker 3: don't observe that. So that to me is a very
• 19:18
  Speaker 3: big tell tale that it's not in falling material heating
• 19:20
  Speaker 3: it up, because in falling material will be episodic and localized.
• 19:25
  Speaker 3: And so you get one bit of the corona bright,
• 19:26
  Speaker 3: then another bit, then another bit, and instead the corona
• 19:29
  Speaker 3: seems to be uniformly hot. Its shape and structure changes
• 19:33
  Speaker 3: though through the solar cycle, and that's tied to the
• 19:35
  Speaker 3: magnetic fields, and that seems to be a hint at
• 19:38
  Speaker 3: what's actually going on. Now. It's absolutely right, we don't
• 19:41
  Speaker 3: know the final answer, but I've been looking around and
• 19:43
  Speaker 3: there was a bit of work came out back in
• 19:45
  Speaker 3: twenty twenty three I think it was that has come
• 19:49
  Speaker 3: up with a potential part of the answer. So the
• 19:53
  Speaker 3: answer here is linked to what researchers have called low
• 19:57
  Speaker 3: amplitude decaleless kin cost relations. All right, again, we're really
• 20:03
  Speaker 3: good at naming things, lad cause I guess if you
• 20:06
  Speaker 3: really wanted an acronym there. So the corona is tied
• 20:12
  Speaker 3: in with the magnetic field of the Sun, and as
• 20:14
  Speaker 3: the sol cycle goes on, the magnetic field gets more
• 20:17
  Speaker 3: and more tangled up, and you get loops and kinks
• 20:20
  Speaker 3: happening near the surface of the son, often tied with
• 20:22
  Speaker 3: sun spots, and this is all tied in with flares
• 20:25
  Speaker 3: and coronal mass ejections, things like this. What this is saying,
• 20:30
  Speaker 3: I think, is that you get oscillations in those magnetic
• 20:33
  Speaker 3: field lines, and the oscillations carry energy from the surface
• 20:37
  Speaker 3: into the corona and can deposit it there. Now, normally
• 20:40
  Speaker 3: those oscillations would be short lived, so you'd only have
• 20:42
  Speaker 3: a short period of time to deposit energy, so they
• 20:44
  Speaker 3: wouldn't be very efficient. But these studies, these observations found
• 20:48
  Speaker 3: a kind of oscillation on those magnetic field lines that
• 20:51
  Speaker 3: is of low frequency, so not carrying much energy per second,
• 20:55
  Speaker 3: but can be long lived because they are be careless,
• 20:58
  Speaker 3: they're not decaying. So get these oscillations that set up,
• 21:01
  Speaker 3: they keep going for minutes or hours, and that gives
• 21:04
  Speaker 3: them a long time to put energy into the corona.
• 21:07
  Speaker 3: So the authors of this worth are talking about the
• 21:10
  Speaker 3: fact that such oscillations, which seem to be really common
• 21:14
  Speaker 3: from their observations, could act to deposit a large amount
• 21:18
  Speaker 3: of energy in the corona. So it's a way of
• 21:20
  Speaker 3: transferring energy from the magnetic field of the Sun into
• 21:22
  Speaker 3: the corona, which then carries that energy away into space,
• 21:26
  Speaker 3: which ties into what we were talking about before actually
• 21:28
  Speaker 3: in the gyrochronology, because it's that energy that has been
• 21:32
  Speaker 3: lost that is transferring angular momentumway into space as well
• 21:35
  Speaker 3: and causing that to slow down. So it is all
• 21:38
  Speaker 3: linked together. Now that study used data from European Space
• 21:42
  Speaker 3: Agency Solar Orbiter NASA's Solo Dynamics Observatory, and they found
• 21:47
  Speaker 3: one of these oscillations that lasted for four minutes. Now
• 21:50
  Speaker 3: four minutes doesn't sound long, but a kink a wobble
• 21:53
  Speaker 3: going off four minutes has a lot of time to
• 21:55
  Speaker 3: deposit energy into space.
• 21:57
  Speaker 2: Yeah.
• 21:57
  Speaker 3: Read more about this. You can have a look online.
• 21:59
  Speaker 3: It wasublished i think September twelve, twenty twenty three in
• 22:03
  Speaker 3: Nature Communications, with the leader author being and apologies for
• 22:07
  Speaker 3: the pronunciation there. It's a solo physicist at the University
• 22:10
  Speaker 3: of Warwick in the UK, and it's Valerie makariyakov Na
• 22:15
  Speaker 3: aariakr V And you can find the findings online in
• 22:20
  Speaker 3: Nature Communications. Their paper will do an infinitely better job
• 22:24
  Speaker 3: of explaining what's going on than I just did, because
• 22:26
  Speaker 3: they're the experts. But that seems to be the latest
• 22:29
  Speaker 3: entry in our attempts to answer the question of WTF. Essentially,
• 22:34
  Speaker 3: what on Earth is going on with the corona? How
• 22:36
  Speaker 3: does it work? And that's how sounds regretted us. You know,
• 22:40
  Speaker 3: we don't know all the answers yet, and that's why
• 22:41
  Speaker 3: this is such a fabulous question. And what Clint has
• 22:44
  Speaker 3: done in coming up with a potential hypothesis for what
• 22:48
  Speaker 3: happens is how scientists actually works. So we do just
• 22:50
  Speaker 3: what Clint did. We come up with an idea this
• 22:52
  Speaker 3: I think is something that could contribute. This is how
• 22:55
  Speaker 3: it could work. And then what happens is that we
• 22:58
  Speaker 3: make predictions from that, which is how I extrapolated it,
• 23:01
  Speaker 3: which is that if it's linked to in following material
• 23:04
  Speaker 3: that's a man driver, what would we see, Well, we'd
• 23:07
  Speaker 3: see the plasus where you get a big fall of material,
• 23:09
  Speaker 3: you get a bright outburst of energy and they will dominate,
• 23:12
  Speaker 3: and we don't see that, so that theory doesn't work.
• 23:15
  Speaker 3: We met testable predictions and tests and this is just
• 23:18
  Speaker 3: another step in the way to work into that answer.
• 23:20
  Speaker 3: So I think it's a wonderful question. It is approaching
• 23:23
  Speaker 3: something that we don't have all the answers for you,
• 23:25
  Speaker 3: but hopefully my answer helps a little bit and understanding
• 23:28
  Speaker 3: just what's going on and what isn't happening.
• 23:30
  Speaker 1: Yeah, it also shows how complex these these things are.
• 23:35
  Speaker 1: I mean, the Sun is the most studied star in
• 23:37
  Speaker 1: the universe as far as we're concerned, and we still
• 23:39
  Speaker 1: haven't figured it out. So there's so many different kinds
• 23:43
  Speaker 1: of stars and they might not all be doing the
• 23:47
  Speaker 1: same thing. So yeah, there's much to learn. Clink, great question,
• 23:50
  Speaker 1: Thanks for sending it in.
• 23:51
  Speaker 3: This is Space Nuts.
• 23:53
  Speaker 1: Andrew Dunkley here with Professor Johndy Horn. Ask space Nuts, Johnny.
• 24:03
  Speaker 1: Our next question comes from one of our younger audience members,
• 24:07
  Speaker 1: and I will hand it over to Sandy and Emily.
• 24:11
  Speaker 5: Good day, friend, Andrew. It's again thank you for answering
• 24:16
  Speaker 5: my last question. That gag about the asteroids pretty funny.
• 24:21
  Speaker 5: Now today my four year old daughter Emily wants to
• 24:25
  Speaker 5: ask a question, so I'm going to pass it on
• 24:27
  Speaker 5: to her. How good week, Gay to Nay. Good job, Emmy,
• 24:32
  Speaker 5: thank you, Thank you for Andrew. Hopefully you can answer
• 24:34
  Speaker 5: this question for us. Jeers.
• 24:37
  Speaker 1: Well, I won't be Fred or Andrew, it will be
• 24:40
  Speaker 1: Johnty and Hi Emily and Sandy's one of our regular contributors.
• 24:44
  Speaker 1: But great to hear from Emily. A giant ladder. Probably not.
• 24:50
  Speaker 3: It's an awesome question and a really good one, Emily,
• 24:53
  Speaker 3: so thank you very much for that. It's difficult. It's
• 24:57
  Speaker 3: the very short thing. So traveling into space is chilling,
• 25:00
  Speaker 3: and this is why we never managed it until nineteen
• 25:03
  Speaker 3: fifty seven when they launched Sputnik one, which was the
• 25:06
  Speaker 3: first thing that went into orbit around the Earth. The
• 25:09
  Speaker 3: Moon's further away. The Moon, on average is about three
• 25:12
  Speaker 3: hundred and eighty four thousand kilometers away. What that means
• 25:16
  Speaker 3: is if you want to get there in a reasonable
• 25:18
  Speaker 3: amount of time, you need to travel really really quickly.
• 25:21
  Speaker 3: If you were to travel on the highway, you're going
• 25:24
  Speaker 3: at one hundred kilometers an hour, it would take you
• 25:27
  Speaker 3: something like three thousand, eight hundred hours to drive there
• 25:30
  Speaker 3: driving at that speed. And I think we've all got
• 25:32
  Speaker 3: better things to do than that. So obviously we can't
• 25:34
  Speaker 3: drive to the Moon, even if we had a road
• 25:36
  Speaker 3: or we had a ladder. What we need to do
• 25:39
  Speaker 3: instead is find a way to get to go very
• 25:41
  Speaker 3: very quickly, and then travel there more rapidly. And put
• 25:45
  Speaker 3: that in perspective. When the first people walked on the
• 25:48
  Speaker 3: Moon back in the late nineteen sixties, took them about
• 25:51
  Speaker 3: three days to get there, so they were traveling a
• 25:54
  Speaker 3: lot quicker than you go when you're driving to school
• 25:56
  Speaker 3: or driving.
• 25:57
  Speaker 1: To work, unless you go piplight Sony car.
• 26:00
  Speaker 3: Yes, even with the p plates, it's a push. I mean,
• 26:03
  Speaker 3: I wish I could do my commute at this kind
• 26:05
  Speaker 3: of speed because it will make life a lot easier. Yes,
• 26:08
  Speaker 3: so there's a few problems with that. You've got to
• 26:11
  Speaker 3: get to a very high speed, which our cars just
• 26:14
  Speaker 3: can't do. But you don't want to just get to
• 26:16
  Speaker 3: that speed instantaneously because the acceleration would be really really
• 26:21
  Speaker 3: violent and really really painful. And you feel this when
• 26:24
  Speaker 3: you feel you know, somebody driving maybe Sandy's driving Emily,
• 26:28
  Speaker 3: and they accelerate from the traffic lights. So the harder
• 26:31
  Speaker 3: they accelerate, the more you're pushed back into your seat.
• 26:34
  Speaker 3: And so the more you're changing speed, the more you
• 26:36
  Speaker 3: feel that. And this is something fighter pilots need to
• 26:39
  Speaker 3: train to practice with because when a fighter jet does
• 26:43
  Speaker 3: a really sharp turn, the pilot can pass out because
• 26:47
  Speaker 3: I think g forces are so extreme that all the
• 26:50
  Speaker 3: blood is pushed out of their brain and they kind
• 26:52
  Speaker 3: of fall asleep, and that's not good. So they have
• 26:54
  Speaker 3: special clothes to deal with this. So what that means
• 26:57
  Speaker 3: is we can't accelerate too quickly insteadtaneously, because that would
• 27:01
  Speaker 3: be bad for the people going. In addition, we've got
• 27:05
  Speaker 3: to get out of the atmosphere and the faster you
• 27:07
  Speaker 3: travel through the Earth's air, the air pushers back at you,
• 27:11
  Speaker 3: so it's really hard to speed up. And you can
• 27:13
  Speaker 3: see this if you get a sheet of paper in
• 27:15
  Speaker 3: your hand and try and push it through the airface
• 27:17
  Speaker 3: onto the air. If you go gently, it's not too bad.
• 27:20
  Speaker 3: The harder you push it, the more the paper will
• 27:21
  Speaker 3: bend back against your hand as it's pushed back by
• 27:23
  Speaker 3: the air resistance. So a big part of getting to
• 27:26
  Speaker 3: space is actually getting out of the earth atmosphere. And
• 27:29
  Speaker 3: the way we've solved all of these problems is to
• 27:32
  Speaker 3: build really really really big rockets with multiple stages and
• 27:36
  Speaker 3: use those to propel objects into space, and then when
• 27:40
  Speaker 3: the first stage is dealt with, it falls away. You
• 27:42
  Speaker 3: get rid of that mass and you get a smaller
• 27:44
  Speaker 3: and smaller spacecraft. So when astronauts went to the Moon
• 27:48
  Speaker 3: of the nineteen sixties, they had this enormous rocket called
• 27:50
  Speaker 3: the Saturn five rocket. You can look at things of it.
• 27:53
  Speaker 3: When I was a kid, we went to Florida and
• 27:56
  Speaker 3: we went and I stood next to the Saturn five rocket.
• 27:59
  Speaker 3: It too, and it's bonkersly big, much.
• 28:03
  Speaker 1: Like it looks big untake. But when you're standing next
• 28:06
  Speaker 1: to it, you go, oh, my gosh, it is very
• 28:09
  Speaker 1: much bigger than you think it's going to be.
• 28:10
  Speaker 3: Yeah, it's long enough that an Olympic sprinter would take
• 28:13
  Speaker 3: about ten seconds to run the length of it. Something
• 28:15
  Speaker 3: like that. Ridiculously big. So that is a giant firework
• 28:19
  Speaker 3: that we built ten nationals to the room to the moon,
• 28:22
  Speaker 3: and it launches it. The rocket engine goes off like firework,
• 28:26
  Speaker 3: pushing them higher and higher into the sky, speeding up
• 28:29
  Speaker 3: at a speed, at an acceleration that anything in the
• 28:32
  Speaker 3: top could manage. So it's uncomfortable and you've been pushed
• 28:36
  Speaker 3: back into your seats, but it's not so extreme. It
• 28:39
  Speaker 3: makes you one well. And that big rocket is made
• 28:43
  Speaker 3: of multiple parts. So when you get quite hoping in
• 28:45
  Speaker 3: the atmosphere and all the fuel is used up in
• 28:47
  Speaker 3: the first part, that falls away, and you've now got
• 28:50
  Speaker 3: a smaller rocket that does the next burn and pushes
• 28:52
  Speaker 3: you even faster and faster, and eventually you get out
• 28:56
  Speaker 3: of the atmosphere. And that's good because you no longer
• 28:58
  Speaker 3: have the wind resistance against you, and you can therefore
• 29:02
  Speaker 3: use less energy to move around because you're not pushing
• 29:04
  Speaker 3: against the wind. So once you're out of the atmosphere
• 29:06
  Speaker 3: it gets easier. What does happen then is that the
• 29:09
  Speaker 3: rocket will do one final boost to get you to
• 29:12
  Speaker 3: a speed where you'll travel towards the Moon, and it
• 29:14
  Speaker 3: will take you two or three days to get there,
• 29:17
  Speaker 3: and you cost you then go into free fall, floating there,
• 29:21
  Speaker 3: just cruising on. And this is a bit like when
• 29:23
  Speaker 3: you've got up to speed on the highway and your
• 29:25
  Speaker 3: car's just going along at the speed limit, minding it
• 29:29
  Speaker 3: neutral and ninja just a bit on neutral, and you
• 29:30
  Speaker 3: just cruise a lot. And at this point you've got
• 29:33
  Speaker 3: a couple of days of the astronauts feeling weightless because
• 29:36
  Speaker 3: they're moving at the same speed as a spacecraft around them,
• 29:39
  Speaker 3: and they just courst along. And then when you get
• 29:41
  Speaker 3: near to the Moon, you're going too quickly to orbit
• 29:44
  Speaker 3: the Moon because you're going at the speed you need
• 29:46
  Speaker 3: to do to get there. So you need to turn
• 29:48
  Speaker 3: around and slow down again to slow down enough to
• 29:50
  Speaker 3: get into orbit around the Moon. And so the rockets
• 29:53
  Speaker 3: burn again, pushing you in the other direction, slowing you
• 29:56
  Speaker 3: down until you're moving on an orbit around the Moon
• 29:58
  Speaker 3: that kind of circul and maybe a few tens of
• 30:01
  Speaker 3: kilometers above the Moon's surface. And he sit there for
• 30:04
  Speaker 3: a while and check that everything's okay, because it's hard
• 30:07
  Speaker 3: work and you want to make sure things are right.
• 30:10
  Speaker 3: But then when the astronauts went to the Moon, the
• 30:12
  Speaker 3: final part was that two of the astronauts on the
• 30:14
  Speaker 3: mission climbed into this small landing module and the third
• 30:18
  Speaker 3: one staid piloting the orbiter. They stayed above the Moon
• 30:21
  Speaker 3: and didn't go down to the surface, but the landing module,
• 30:24
  Speaker 3: separated from the orbitter, got nudged away and then used
• 30:27
  Speaker 3: its own small little rockets to boost and slow down
• 30:30
  Speaker 3: and boost and slow down until it touched down and
• 30:33
  Speaker 3: landed safely at a specific point on the Moon, and
• 30:36
  Speaker 3: the pilot had to watch up what they were doing.
• 30:38
  Speaker 3: They were kind of looking out at the ground below
• 30:40
  Speaker 3: to pick the best place to land. And with the
• 30:42
  Speaker 3: very first landing, when Neil Armstrong and Buzz Aldering landed
• 30:45
  Speaker 3: on the Moon, they kept going and kept going and
• 30:47
  Speaker 3: nearly run out of fuel. They only had a few
• 30:49
  Speaker 3: seconds left before they would have to abort and boost
• 30:52
  Speaker 3: back up, because when you land on the Moon, you've
• 30:54
  Speaker 3: got to get back. So the land on the Moon,
• 30:57
  Speaker 3: they do all their fun things. They bounce around like kangaroos.
• 31:00
  Speaker 3: But then to get back to Earth, they've got to
• 31:02
  Speaker 3: get back in this small landing module which is probably
• 31:05
  Speaker 3: not got much more room in it, to be honest
• 31:07
  Speaker 3: in the interior of your car, strap themselves in and
• 31:11
  Speaker 3: then the top of the module detaches, leaving the legs behind.
• 31:15
  Speaker 3: The rocket pushes them back up so they can get
• 31:17
  Speaker 3: into orbit around the Moon. They dock and reconnect with
• 31:21
  Speaker 3: the parent spacecraft that the pilot was sad in waiting
• 31:25
  Speaker 3: for a couple of days on their own. Then they
• 31:27
  Speaker 3: turn on their rockets and they come back to the
• 31:29
  Speaker 3: Earth send thing. They boost up up to a high speed,
• 31:33
  Speaker 3: then their cruise along, floating there for a couple of
• 31:35
  Speaker 3: days until they get near the Earth. Then they boost
• 31:37
  Speaker 3: their rockets again to slow down, fall into the atmosphere
• 31:40
  Speaker 3: and land again. So it's a big, long, dramatic journey.
• 31:44
  Speaker 3: Now we've got better technology now so we can do
• 31:47
  Speaker 3: it more effectively, and that's why NASA are hoping to
• 31:50
  Speaker 3: send people back to the Moon in the next few
• 31:52
  Speaker 3: years now. Everybody who went to the Moon so far,
• 31:56
  Speaker 3: all twelve people who walked on the Moon where people
• 31:58
  Speaker 3: who looked a bit like me and Andrew Fred. There
• 32:00
  Speaker 3: were all the white men and that was it. And
• 32:05
  Speaker 3: you know, these were all people who trained as test
• 32:06
  Speaker 3: pilots and stuff like this. With the next people landing
• 32:10
  Speaker 3: on the moon, they're going to be, you know, a
• 32:13
  Speaker 3: wider variety of people. So the hope is that in
• 32:15
  Speaker 3: a few years time we'll see the first woman walk
• 32:17
  Speaker 3: on the moon and the person who isn't white to
• 32:20
  Speaker 3: walk on the moon as well, And that'll be really
• 32:23
  Speaker 3: good because it's important to know that this is something
• 32:25
  Speaker 3: anybody can do. Everybody could learn to be an astronaut.
• 32:28
  Speaker 3: It's very competitive and really hard. But if you only
• 32:31
  Speaker 3: ever see people who look like Me and Andrew do it,
• 32:34
  Speaker 3: you'll think they're the only kind of people who can.
• 32:36
  Speaker 3: So it's really important to have everybody represented in this.
• 32:40
  Speaker 3: And I think it's really exciting that in a few
• 32:42
  Speaker 3: years time we want to just talk about men walking
• 32:44
  Speaker 3: on the moon, but we'll talk about men and women
• 32:47
  Speaker 3: walking on the moon. That's going to be really cool. Yes,
• 32:49
  Speaker 3: it is.
• 32:50
  Speaker 1: I grew up in the pioneering era of space flight
• 32:55
  Speaker 1: and going to the Moon, and I was quite young
• 32:58
  Speaker 1: when Neil Armstrong his foot on the surface and was
• 33:01
  Speaker 1: followed by Buzz Alder, and I was so very lucky
• 33:04
  Speaker 1: to meet buzz Aldron many many years later and I
• 33:07
  Speaker 1: got to interview him for the Australian Broadcasting Corporation. That
• 33:10
  Speaker 1: was probably one of the highlights of my career, to
• 33:13
  Speaker 1: be honest, to meet someone so famous, one of the
• 33:15
  Speaker 1: most famous people in the world because of what he did.
• 33:18
  Speaker 1: But it's reached a point now where people are going
• 33:20
  Speaker 1: up and down all the time into space and will
• 33:23
  Speaker 1: never know their names because it's become so common. But
• 33:27
  Speaker 1: as you say, with Artemis going back to the Moon
• 33:29
  Speaker 1: and those people setting foot on the surface again, men
• 33:32
  Speaker 1: and women of multiple races, they will again reignite that
• 33:38
  Speaker 1: fame that goes with doing something so extraordinary. And Emily,
• 33:42
  Speaker 1: I would imagine that in your lifetime it will reach
• 33:45
  Speaker 1: a point where there will be people living on the Moon.
• 33:49
  Speaker 1: I expect that will happen, might even happen in my lifetime,
• 33:54
  Speaker 1: but certainly in yours it'll be very different, maybe even Mars. Emily,
• 33:59
  Speaker 1: Thank you so the question, Thanks Sandy, always great to
• 34:02
  Speaker 1: hear from our younger listeners. Johny, I'm going to make
• 34:06
  Speaker 1: an executive decision and I'm going to Pigeonhole Fenton until
• 34:10
  Speaker 1: next week because his question is two hours long, and
• 34:14
  Speaker 1: I imagine the answer will be five times that, so
• 34:17
  Speaker 1: I just don't think we can fit it in today.
• 34:20
  Speaker 1: But it's a great question about the radiation of Jupiter.
• 34:22
  Speaker 1: We will put that at the top of the tree
• 34:25
  Speaker 1: for next week's Q and A episode. But thanks to
• 34:28
  Speaker 1: everyone who contributed, and don't forget. If you've got questions
• 34:30
  Speaker 1: for us, jump on our website space nuts podcast dot
• 34:33
  Speaker 1: com and space nuts dot io to URLs and just
• 34:38
  Speaker 1: click on that little AMA link at the top. That's
• 34:41
  Speaker 1: where you send you text and audio questions. If you've
• 34:43
  Speaker 1: got a device with a microphone, you're all set. Have
• 34:46
  Speaker 1: a look around while you're there, and don't forget our
• 34:48
  Speaker 1: social media very very active. The space nuts Facebook page
• 34:53
  Speaker 1: is our official page, but we've got the space Nuts
• 34:56
  Speaker 1: podcast group facebook page where people get together and chat
• 35:00
  Speaker 1: and talk and compare photos and notes, and yeah, it's
• 35:04
  Speaker 1: very very active. It's a great site. And thanks to
• 35:07
  Speaker 1: our administrators who look after it for us because I
• 35:10
  Speaker 1: haven't got time most of the time, except when i've
• 35:12
  Speaker 1: got time and it's time to go. Thank you very much, Johnny.
• 35:18
  Speaker 1: Always great fun. We'll catch you next week.
• 35:20
  Speaker 3: That's your ladder. Thank you for having me.
• 35:22
  Speaker 1: Johnny Horner, professor of astrophysics at the University of Southern Queensland,
• 35:29
  Speaker 1: joining us while Fred is away. And we'll speak to
• 35:33
  Speaker 1: Johnty again next week and to hear you in the studio.
• 35:37
  Speaker 1: He was a wall because he's putting peeplates on his
• 35:40
  Speaker 1: car so that he can go faster. And from me
• 35:43
  Speaker 1: Andrew Dunkley, thanks for your company. Will catch you on
• 35:46
  Speaker 1: the very next episode of Space Nuts. Bye byepauts to.
• 35:51
  Speaker 3: The Space Nuts podcast, available at Apple Podcasts, Spotify, iHeartRadio,
• 35:59
  Speaker 3: or your favorite podcast player. You can also stream on
• 36:02
  Speaker 3: demand at bites dot com.
• 36:04
  Speaker 4: This has been another quality podcast production from sites dot com.