Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Galactic Queries: Black Hole Lifespans, Lunar Impacts & Sun-Seeking Missions

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Galactic Queries: Black Hole Lifespans, Lunar Impacts & Sun-Seeking Missions · Space Nuts: Astronomy Insights & Cosmic Discoveries

• 0:00
  Professor Fred Watson: Hi there.
• 0:01
  Andrew Dunkley: Andrew Dunkley here, and you're listening to
• 0:03
  Space Nuts. It's a Q and A edition. This is
• 0:05
  where we take audience questions. We put them
• 0:08
  in a barrel, we pluck one out and we go, now
• 0:10
  that's too hard. And we just keep doing that
• 0:13
  over and over again until we find four easy
• 0:15
  ones. Uh, today we've got questions about
• 0:18
  black hole evaporation.
• 0:21
  Simple. Uh, Jordy atmosphere,
• 0:24
  uh, Artemis 2, and those, uh, moon
• 0:27
  meteorites that they witnessed. Somebody's
• 0:29
  thrown in a question about that. And missions
• 0:31
  to the sun. Don't forget your sunscreen.
• 0:34
  That's all coming up on this episode of space
• 0:37
  nuts.
• 0:37
  Professor Fred Watson: 15 seconds. Guidance is internal.
• 0:40
  10, 9. Ignition
• 0:42
  sequence start. Space nuts. 5, 4, 3,
• 0:45
  2.
• 0:46
  Speaker C: 1.
• 0:46
  Professor Fred Watson: 2, 3, 4, 5, 5, 4, 3, 2,
• 0:49
  1.
• 0:49
  Andrew Dunkley: Space nuts.
• 0:51
  Professor Fred Watson: Astronauts report it feels good.
• 0:53
  Andrew Dunkley: And joining us to try and solve all of those
• 0:56
  little riddles is Professor Fred Watson,
• 0:58
  astronomer at large. Hello, Fred.
• 1:00
  Professor Fred Watson: Good day, Andrew.
• 1:03
  Andrew Dunkley: Nearly say good morning or good afternoon or
• 1:05
  good evening. Because it might not be that.
• 1:07
  When people listen to us, on the
• 1:09
  Professor Fred Watson: other hand, it is a day. I could say good
• 1:11
  night.
• 1:11
  Andrew Dunkley: Yeah, yeah.
• 1:12
  Professor Fred Watson: Anyway, it's certainly a day. Daytime here.
• 1:17
  Andrew Dunkley: All is well with you, I assume?
• 1:19
  Professor Fred Watson: Um, apparently, um, still seem to have.
• 1:22
  That's a good answer I'm supposed to have.
• 1:23
  Yes. Well, it can only be apparently, because
• 1:26
  you never really know, do you? What's going
• 1:28
  on inside, what's going on?
• 1:32
  The things that you haven't found out about
• 1:33
  yet. Yes, all well so far.
• 1:37
  Andrew Dunkley: I recently had a profile piece
• 1:40
  done by the Cancer Council in Australia for
• 1:42
  Men's Health Week because of what You've been
• 1:45
  dealing with the last three and a half years.
• 1:46
  So, uh, to encourage men to
• 1:49
  go and get their PSA tests and, uh,
• 1:52
  get their, let's just say, junk
• 1:55
  checked out to make sure that they're free
• 1:57
  and clear. And, um, I
• 2:00
  think it's a very important message. But one
• 2:02
  of the things I've learned, uh, through the
• 2:05
  treatment and discussions I've had over the
• 2:07
  last three and a half years in regard to
• 2:09
  prostate cancer is that because I have
• 2:12
  now had it, there is a possibility
• 2:15
  that my three children have a
• 2:17
  50% higher chance of developing it in their
• 2:19
  lives. So it's not just about you.
• 2:23
  Professor Fred Watson: Yes, exactly.
• 2:24
  Andrew Dunkley: It's not just about you as an individual.
• 2:27
  If you've got, um, sons, it's
• 2:30
  about them too. So it makes it even more
• 2:32
  important to get tested.
• 2:34
  Professor Fred Watson: Absolutely.
• 2:35
  Andrew Dunkley: And you don't just have to be in Australia.
• 2:36
  This can happen to any male on the planet.
• 2:39
  So go and get
• 2:42
  that, uh, Prostate test done
• 2:45
  for peace of
• 2:45
  Mendham, lecture
• 2:48
  over. Uh, let's deal with
• 2:51
  some questions, Fred.
• 2:53
  Um, we will go to our first one. This is a
• 2:56
  pretty short and sweet one, but it's, um,
• 2:59
  a complicated issue really. Uh, black holes
• 3:02
  are gaining Massey, if
• 3:04
  they are colder than the cmb,
• 3:07
  how much does this lengthen the
• 3:10
  time before they evaporate? That's a
• 3:13
  question from Bob.
• 3:15
  Professor Fred Watson: So I'm interested in who this question has
• 3:18
  come from because I've got a very old friend
• 3:20
  by the name of Bob Argyle, uh, which is the
• 3:23
  name on the email you sent me.
• 3:25
  Andrew Dunkley: It is.
• 3:26
  Professor Fred Watson: Uh, we worked together in the Royal Greenwich
• 3:28
  Observatory, uh, at a place called
• 3:30
  Herstmonceux Castle in the south of England
• 3:32
  in the early 70s. Uh, now, Bob went
• 3:35
  to Cambridge and I think he's still there. I
• 3:38
  wondered if there was any clue to his
• 3:40
  whereabouts in your email.
• 3:42
  Andrew Dunkley: Um, no, because what you see
• 3:45
  is what you get.
• 3:46
  Professor Fred Watson: What you get. Okay.
• 3:49
  Anyway, well, if it's Bob. G', day, Bob.
• 3:52
  Good to hear from you. We should email
• 3:55
  one day. Yes, um, it's good, Good to
• 3:58
  hear he's still going strong, if it is. And
• 3:59
  if it's not, um, I apologise that I'm mixing
• 4:02
  you up with somebody else. Uh, but it's a
• 4:05
  great question and it's one that, uh,
• 4:08
  I had to, um, do some homework
• 4:10
  on before, um, before the, before the show.
• 4:14
  Um, and the,
• 4:17
  the bottom line is, first of all, what's the
• 4:20
  cmb? The cosmic microwave background. That
• 4:22
  is the, basically the flash of the
• 4:25
  Big Bang, which we still see. Uh,
• 4:29
  when that light was emitted, it was bright,
• 4:31
  white light. Uh, as the universe has
• 4:34
  expanded, that radiation has expanded
• 4:37
  also. It's been stretched, the waves have
• 4:39
  been stretched into microwave
• 4:42
  waves. So we see this background
• 4:45
  of, um, microwave light over the
• 4:48
  whole sky and we can deduce lots of things
• 4:50
  from it. Um, it corresponds to a time, I
• 4:53
  think it was about 380,000 years after the
• 4:55
  Big Ban, when the universe basically,
• 4:59
  um, stopped being bright and a fog of
• 5:03
  radiation, uh, everywhere, which it
• 5:05
  was until that time. So that's the cmb. Now,
• 5:08
  what the CMB does is give space
• 5:11
  a temperature. And the temperature
• 5:14
  is 2.73
• 5:17
  degrees Kelvin, uh, degrees above
• 5:19
  absolute zero. And
• 5:22
  so, uh, that is when
• 5:25
  you compare it with the temperature of
• 5:28
  a black hole. And we've discussed this
• 5:30
  before, Andrew, uh, on The Q&As,
• 5:33
  black hole temperatures are very, very
• 5:36
  cold. Um, typically,
• 5:39
  um, a few tens of nanokelvin.
• 5:42
  That means a few tens of billionths of
• 5:45
  a degree above absolute zero. Compared with
• 5:47
  the 2.73 degrees. And so,
• 5:50
  um, that, uh, that temperature.
• 5:53
  What that means then is that,
• 5:56
  uh, photons of cosmic microwave
• 5:59
  background radiation, uh, can
• 6:02
  be added to the mass of a black
• 6:05
  hole because,
• 6:08
  uh, the temperature of the black hole is
• 6:11
  colder than the temperature of the background
• 6:13
  radiation. So,
• 6:17
  uh, there is an issue, uh,
• 6:20
  which is one that Bob raises.
• 6:23
  Uh, I've lost my question here. It is, how
• 6:26
  much does this lengthen the time before they
• 6:28
  evaporate? So if you've got a situate, we
• 6:31
  know that black holes evaporate. Um,
• 6:34
  the situation that was highlighted by
• 6:36
  Stephen Hawking back in the 70s. Black holes
• 6:39
  evaporate over very, very long
• 6:41
  periods of time. Uh, but what Bob's
• 6:44
  saying or asking is, does the fact
• 6:47
  that they're gaining mass because the cosmic
• 6:50
  microwave background is warmer than the black
• 6:52
  hole, does that extend this time
• 6:54
  significantly? Uh, I had to go
• 6:57
  to AI to answer this question because it's
• 7:00
  got some very, very lengthy
• 7:02
  calculations. Uh, but the answer
• 7:05
  is, uh, it's, um.
• 7:08
  Well, as the AI tool I used says, it
• 7:11
  was practically negligible. Oh, um,
• 7:14
  uh, changing the final lifespan by less than
• 7:17
  one part in 10 to the power 50. So
• 7:20
  that is definitely negligible. Uh,
• 7:23
  and it's because of the,
• 7:26
  uh. It's about the length of
• 7:28
  time that the
• 7:31
  cosmic microwave background radiation feeds
• 7:33
  the black hole. And it turns out that,
• 7:37
  um, the black hole is
• 7:39
  effectively evaporating
• 7:42
  faster than the stuff that it's. That's
• 7:45
  feeding it. And so it
• 7:48
  basically extends the life of the black
• 7:50
  hole by a very, very small amount
• 7:53
  indeed. Uh, there's plenty on the web
• 7:56
  about this if you really want to get into the
• 7:58
  nitty gritty of it. But, um, it is a
• 8:01
  really interesting question, one
• 8:04
  that I have to say, Andrew, had not occurred
• 8:07
  to me before. Uh, so I'm very,
• 8:10
  uh, glad that Bob has raised it and I
• 8:13
  appreciate him doing that. And if it is you,
• 8:15
  Bob, I've still got your record of Das
• 8:18
  Rheingold in my record cabinet behind
• 8:21
  me. The one that you gave me back in
• 8:23
  1973.
• 8:24
  Andrew Dunkley: Well, he doesn't want it back. No, that's the
• 8:27
  other thing that said in the email. Don't
• 8:29
  send that back. It's rubbish. No, I don't
• 8:32
  know. But maybe Bob could message us again
• 8:34
  just to confirm or deny.
• 8:36
  Professor Fred Watson: Yes, I know nothing of Fred Watson.
• 8:39
  Andrew Dunkley: Yes, never met him. I don't want to.
• 8:42
  Professor Fred Watson: I don't want to know.
• 8:44
  Andrew Dunkley: Um, the other interesting thing that comes
• 8:46
  from that is, uh, because of, uh, how cold a
• 8:49
  black hole is, um, if you get too Close. You
• 8:51
  turn not only into spaghetti, but cold
• 8:53
  spaghetti and that. Have you ever eaten that?
• 8:56
  It's horrible.
• 8:57
  Professor Fred Watson: It's not nice. No, you're right. It's the
• 8:59
  worst of all worlds, isn't it?
• 9:00
  Andrew Dunkley: Gosh, it just gets worse. These black holes
• 9:02
  are just starting to m. Make things even more
• 9:04
  horrible. Yeah, thanks, Bob.
• 9:07
  Great question and thanks for sending it in
• 9:10
  and we, uh, look forward to hearing from you
• 9:12
  again.
• 9:12
  Our next question, Fred, comes from
• 9:15
  Greg. Uh, hello, Fred and Andrew. It's Greg
• 9:18
  from Minnesota. Coincidentally,
• 9:20
  Greg is the only Greg in
• 9:23
  Minnesota.
• 9:25
  Professor Fred Watson: That's just as well, I believe.
• 9:28
  Andrew Dunkley: Maybe not. Uh, he says Titan is just a
• 9:31
  moon of Saturn. I mean just a moon of Saturn.
• 9:33
  That's all it is. It's nothing important.
• 9:35
  Anyway, it has an atmosphere so thick the
• 9:37
  pressure is 1 1/2 times Jordy
• 9:40
  Venus is just a bit smaller than Jordy and
• 9:43
  its atmospheric pressure is 90 times
• 9:45
  Jordy give or take. Uh, does Jordy have an
• 9:48
  unusually thin atmosphere for a rocky planet
• 9:51
  this size? If so, could our
• 9:54
  wispy atmosphere be because it all got
• 9:56
  blown away by fear? Love the
• 9:59
  show. Uh, thank you, Greg. Uh, the one and
• 10:02
  only Greg in Minnesota.
• 10:04
  Um, that's a really interesting question.
• 10:07
  Uh, I've never really thought of Jordy
• 10:09
  atmosphere as maybe being, you know,
• 10:12
  thin and wispy. Thin and wispy. But, um,
• 10:16
  it generally is. When you look at photos of
• 10:18
  Jordy from space and you
• 10:21
  identify the atmosphere, oh, it makes
• 10:24
  you cringe a bit because you think, is that
• 10:26
  it? Is that all it is?
• 10:29
  Professor Fred Watson: I mean, 10 kilometres, you're above
• 10:32
  75% of it. It's scary
• 10:35
  in that regard. So you're you
• 10:38
  when you're in a jet, you're above most of
• 10:40
  the atmosphere. Uh, quite extraordinary.
• 10:44
  Yes, it's thin and wispy, exactly as
• 10:47
  Greg says.
• 10:48
  Um, so
• 10:52
  let's deal with these objects first.
• 10:54
  Titan. Uh, and yes,
• 10:57
  just a moon. It's the second largest moon in
• 11:00
  the solar system. It's bigger than the planet
• 11:02
  Mercury. Uh, it's got, but
• 11:05
  it does have about one and a half times the
• 11:07
  atmospheric pressure of our own planet
• 11:10
  and that's largely due
• 11:13
  to the difference in temperature between
• 11:15
  Jordy and Titan. Um,
• 11:18
  so Titan has
• 11:21
  temperatures, it's in the surface
• 11:23
  temperatures around about minus 180,
• 11:26
  minus 190 Celsius. And of
• 11:29
  course that's cold enough for its surface
• 11:32
  to be solid ice, water ice and to have
• 11:34
  liquid natural, uh, gas, ethane and
• 11:37
  methane lakes on its surface, lakes and
• 11:40
  seas. Uh, it's also got this very thick
• 11:43
  atmosphere. Um, so these,
• 11:45
  the molecules of Gas in
• 11:49
  Titan's atmosphere are very cold
• 11:52
  and so they don't sort of bubble
• 11:55
  up to be the. To get up to
• 11:58
  escape velocity. And so basically you've
• 12:01
  got an entrapment of this,
• 12:04
  um, atmosphere. Um, of
• 12:07
  m. I think it's mostly nitrogen. Thinking,
• 12:10
  uh, about it. Um, actually it
• 12:13
  is just checking a number here. It's 90, uh,
• 12:15
  5% nitrogen, uh, and the rest is
• 12:18
  methane and other hydrocarbons. So,
• 12:21
  yes. So it's um. The
• 12:24
  nitrogen atmosphere, very, very cold,
• 12:26
  doesn't have enough energy to sort of
• 12:29
  disappear off into space. So its pressure is
• 12:31
  much higher than Jordy Um, it's a
• 12:34
  similar storey in regard to Venus,
• 12:37
  only kind of more so. Uh,
• 12:40
  because, um, with
• 12:42
  Venus we have the situation
• 12:46
  that, um.
• 12:48
  Uh,
• 12:51
  excuse me, sorry, I've just CLOiD the page I
• 12:53
  was looking at here. Uh, which is not what I
• 12:56
  wanted to do. Um, let me
• 12:59
  just bring it back.
• 13:00
  Andrew Dunkley: So we've all been there, Fred. We've all done
• 13:03
  that.
• 13:04
  Professor Fred Watson: Yeah. So, um, we've got a pressure.
• 13:06
  It's roughly 90 times
• 13:10
  Jordy uh, which is, uh,
• 13:13
  kind of unbelievable. Um, why is
• 13:16
  that? It is because the atmosphere is
• 13:18
  mostly carbon dioxide, which is a
• 13:21
  dense gas. As you know, it's uh, uh, heavier
• 13:24
  than air. Um, and so that
• 13:28
  basically, uh, increases the
• 13:30
  atmospheric pressure. Uh,
• 13:33
  we know that, uh, it's had this, you know,
• 13:36
  runaway greenhouse effect because there is so
• 13:38
  much carbon in the atmosphere
• 13:42
  and that's essentially the carbon dioxide
• 13:44
  traps the heat. You've got the runaway
• 13:46
  greenhouse effect. So you've got a surface
• 13:48
  temperature which I think is in the region of
• 13:51
  460 degrees Celsius.
• 13:54
  Um, so the question, I guess
• 13:59
  the real nub of Greg's question
• 14:01
  is why isn't the Jordy like that? Was it all
• 14:04
  blown away by theia? And the answer
• 14:07
  is maybe,
• 14:10
  probably not, but maybe in a way because
• 14:13
  what keeps our atmosphere
• 14:16
  temperate, uh, is what's
• 14:18
  called the carbon cycle. It's the fact that
• 14:21
  we have, uh. Basically we've got a planet
• 14:24
  whose surface is divided into tectonic
• 14:26
  plates. Those plates slide around one
• 14:29
  another and you get a, uh, volcanism,
• 14:32
  uh, putting carbon into the atmosphere.
• 14:35
  That carbon sinks down into the
• 14:38
  ocean and eventually gets subsumed back
• 14:41
  underneath. Uh, the, um,
• 14:45
  uh, continental plays. Uh, that's the
• 14:47
  mechanism. And that, uh, circulation of
• 14:50
  carbon acts as a kind of thermostat. It's
• 14:53
  what keeps the Jordy uh, temperature
• 14:55
  reasonable. Uh, uh.
• 14:58
  The reason why I said there might be a link
• 15:00
  with THEIA is I guess it's possible that
• 15:03
  THEIA had something to do with the Origin of
• 15:06
  tectonic plates. Although my understanding.
• 15:09
  Andrew Dunkley: So not a direct correlation,
• 15:11
  but maybe something, you know, an after
• 15:14
  effect.
• 15:14
  Professor Fred Watson: Yes, that's right. The consequences. We've
• 15:17
  got tectonic plates, uh, which
• 15:19
  stabilise the atmosphere and that might have
• 15:22
  something to do with Theia. Although my
• 15:24
  understanding of the Theia impact is that the
• 15:27
  Jordy at that time was probably
• 15:29
  um, basically a magma world. It was, it
• 15:32
  probably had a molten surface.
• 15:35
  Andrew Dunkley: So would it have not had an
• 15:38
  atmosphere at all or maybe just something
• 15:40
  really sinister and nast?
• 15:43
  Professor Fred Watson: Yeah, I think it had pretty nasty stuff in
• 15:44
  its atmosphere. There would have been an
• 15:45
  atmosphere there which was probably highly
• 15:48
  toxic and uh, not good for
• 15:51
  future planet Jordy So
• 15:54
  um, there could be a link with Theia.
• 15:57
  I suspect not. As I said, I think my
• 16:00
  understanding of the latest idea on the Thea
• 16:03
  impact is that the Jordy had basically a
• 16:06
  magma ocean when the impact took place. And
• 16:08
  that's why, um,
• 16:13
  the structure of the moon, the isotopes in
• 16:15
  the moon are more related to
• 16:18
  the Jordy uh, isotopes than
• 16:21
  what THEIA might have had. We don't know what
• 16:24
  isotopic ratios there were on Theia. We don't
• 16:26
  know exactly what elements were there. Uh,
• 16:29
  but the moon is made of stuff largely similar
• 16:32
  to the Jordy Okay, all right.
• 16:34
  Andrew Dunkley: Um, but yes, we do live on
• 16:37
  a planet with a um, thin and
• 16:40
  wispy atmosphere and we, we should
• 16:43
  do as much as we can to protect it.
• 16:45
  Professor Fred Watson: Keep it there. That's right.
• 16:46
  Andrew Dunkley: Although, although you did, um, you gave me
• 16:49
  an idea. I mean if, if carbon comes out of
• 16:51
  the volcanoes, goes back into the ocean and
• 16:53
  then eventually gets sucked back down through
• 16:55
  the tectonic plates. We're not
• 16:58
  wrong to throw all our rubbish in the ocean.
• 17:00
  By the sound of a threat, we should keep
• 17:02
  doing that.
• 17:04
  Professor Fred Watson: Uh, yes, I think there
• 17:07
  might be arguments against that. Yeah,
• 17:08
  probably are.
• 17:09
  Andrew Dunkley: Yes, yes, don't, don't do anything usually
• 17:11
  wrong. Uh, but thank, uh, you very much,
• 17:14
  Greg for sending in your question.
• 17:16
  This is Space Nuts with Andrew Dunkley and
• 17:19
  Professor Fred Watson.
• 17:23
  Speaker D: Three, two, one.
• 17:26
  Andrew Dunkley: Space Nuts. Okay Fred, we got a couple
• 17:29
  of audio questions, uh, so let's get into
• 17:32
  those. The first one comes, uh, this one
• 17:34
  comes from Switzerland.
• 17:38
  Speaker D: Hello Fred and Andrew, this is Michael from
• 17:40
  Switzerland. I have a
• 17:43
  question for you regarding the
• 17:46
  Artemis 2 mission. So, uh,
• 17:50
  there it is claimed that they have
• 17:53
  visuals of meteorite impacts
• 17:56
  on um, the moon's far side.
• 18:00
  So uh, my question is how
• 18:03
  do we discriminate uh, these
• 18:06
  uh, one person side things
• 18:09
  from physiological, uh, impact
• 18:12
  of uh, high energy
• 18:14
  radiation with the human retina
• 18:17
  in in space,
• 18:21
  um, one person,
• 18:23
  visual, uh, to my knowledge, is
• 18:26
  not a scientific evidence. So you need uh,
• 18:29
  at least two or more
• 18:32
  individual, uh, sightings of the
• 18:35
  same event, uh, or at
• 18:38
  least a technical, um,
• 18:41
  sighting. So, uh, what is your
• 18:44
  opinion on that? Because this
• 18:47
  makes uh, big wave, uh, in the,
• 18:50
  in the community. And uh,
• 18:53
  I'm not sure whether they really have seen
• 18:56
  meteorite impact or just were fooled by their
• 18:59
  own side. Thank you for
• 19:02
  answering and love your show. Bye.
• 19:05
  Bye.
• 19:05
  Andrew Dunkley: Thank you. Michael. Uh, I
• 19:08
  mean, it's a good question to ask because,
• 19:11
  uh, all I've heard is that
• 19:14
  there were four astronauts on Artemis 2,
• 19:17
  uh, that went around the moon,
• 19:19
  um, as far as I'm aware,
• 19:22
  and I've just double checked it, all four of
• 19:25
  them witnessed this event.
• 19:30
  So it wasn't just one,
• 19:32
  as far as we're aware.
• 19:35
  Professor Fred Watson: Um, it's a bit more complicated than that,
• 19:37
  Andrew.
• 19:38
  Andrew Dunkley: I had suspected it would be.
• 19:39
  Speaker C: Yeah.
• 19:42
  Professor Fred Watson: So there were
• 19:44
  the Gary.com of four and
• 19:47
  six impact flashes were
• 19:50
  observed, uh, uh, and I
• 19:53
  think there is a breakdown, um,
• 19:56
  which I have had, but
• 19:58
  can't lay my hands on it as to. Oh, here
• 20:01
  we are. Yeah. Um, Reid Wiseman
• 20:04
  was the commander. He saw
• 20:07
  two impacts. Jeremy
• 20:10
  Hansen observed another two.
• 20:13
  And uh,
• 20:16
  I think also the other two
• 20:19
  Gary.com members observed some.
• 20:22
  But, uh, the bottom line here is
• 20:25
  Andrew Dunkley: they only saw them one at a time.
• 20:27
  Professor Fred Watson: Were they. Yes. Were they
• 20:30
  seen together? And,
• 20:33
  um, once again my AI assistant,
• 20:36
  uh, says the specific number of flashes
• 20:40
  definitively witnessed by more than one
• 20:42
  astronaut at the exact same moment has
• 20:45
  not been isolated from the total Nally by
• 20:48
  nas. So we
• 20:50
  don't know whether any of them
• 20:53
  saw the same, you know, more than one of them
• 20:56
  saw the same flash.
• 20:59
  And in that regard, Michael's got a very good
• 21:02
  point. I think because one
• 21:05
  visual sighting isn't really
• 21:08
  a scientific observation. It needs to be,
• 21:11
  uh, somehow corroborated. And you know,
• 21:14
  one way of doing that would have been
• 21:15
  photography. Uh, but I don't think there were
• 21:18
  any photographic or imaging records
• 21:21
  of these flashes. So I think he's right to
• 21:24
  raise the question, uh, because we do know
• 21:27
  that, uh, subatomic particles, and this
• 21:30
  is particularly cosmic rays, pass through the
• 21:33
  body and can uh, essentially
• 21:37
  give you a flash on the retina as they go
• 21:39
  through one of your retinal cells. They can
• 21:43
  basically excite it, uh, and you see a flash
• 21:45
  of light. I'm pretty sure You've been them
• 21:47
  myself. A single flash
• 21:51
  against a black background. Certainly
• 21:54
  the electronic detectors that we used to use
• 21:57
  at Siding Spring Observatory, they're
• 21:58
  probably better these days. Were Very
• 22:01
  susceptible to these cosmic ray events. So
• 22:03
  when you took an image, uh, you found that a
• 22:06
  lot of flashes, sometimes lines where the
• 22:08
  cosmic ray has gone. Actually
• 22:11
  entered in the plane of the detector. So it's
• 22:13
  gone through many pixels and excited them
• 22:16
  all. Um, so it's a real phenomenon.
• 22:19
  Now,
• 22:22
  my instinct would be that there might be
• 22:25
  a differentiation in the duration of these
• 22:28
  flashes. Because cosmic ray flashes on your
• 22:30
  retina are, uh, extremely brief. Uh,
• 22:33
  but I think the flashes observed by
• 22:36
  the Artemis astronauts were also
• 22:40
  extremely brief, uh, in
• 22:42
  the region of milliseconds, probably.
• 22:46
  Um, and that's. You probably
• 22:48
  would not be able to tell the difference
• 22:50
  between one and the other. And, uh,
• 22:53
  again, they're in a high radiation
• 22:56
  environment. They are,
• 22:58
  uh, in orbit around the moon. They are,
• 23:02
  um, shaded from the radiation field
• 23:05
  of the sun, the direct radiation field of the
• 23:07
  sun, because the moon's in the way. Uh, they
• 23:09
  were looking at these on the dark side of the
• 23:11
  moon, but the cosmos as a whole was open to
• 23:14
  them. And that's where cosmic rays come from.
• 23:15
  They come from the universe, generally.
• 23:18
  So I, uh, think Michael raises a good point,
• 23:21
  and it's one. It'd be nice to get a bit
• 23:24
  more knowledge of this to see if we can get
• 23:27
  some eyewitness accounts from the Artemis
• 23:29
  astronauts. They may be writing their memoirs
• 23:32
  or whatever at the moment. It would be very
• 23:35
  good to see if any of them can corroborate
• 23:38
  these millisecond long, uh,
• 23:40
  flashes of light.
• 23:42
  Andrew Dunkley: Yeah. It says a lot though, about the
• 23:44
  sensitivity of the human eye though, doesn't
• 23:46
  it?
• 23:46
  Professor Fred Watson: It does, yes. Yes. Well, it all does, we
• 23:49
  think, um, there have been experiments done,
• 23:52
  uh, quite some time ago that suggest that the
• 23:55
  human eye can almost detect individual
• 23:57
  photons, kind
• 24:00
  of, you know, perhaps groups of five or
• 24:03
  something like that are, ah, detectable. I
• 24:05
  can't remember the details of it, but yeah, a
• 24:07
  good, uh. Well, well thought out, um,
• 24:10
  uh, question from Michael there. To which we
• 24:13
  don't really have the exact answer. No.
• 24:15
  Andrew Dunkley: I Space if, um, they do
• 24:18
  write a report or something, they might be
• 24:21
  able to, um, clarify what
• 24:24
  exactly was seen and who saw it and how
• 24:27
  many of them at the same time, etc.
• 24:29
  Uh, but if it turns out that they only each
• 24:32
  saw this phenomenon
• 24:35
  individually, then probably, uh, it remains
• 24:38
  just a, um, I don't know, a casual
• 24:41
  observation, not a, A scientific
• 24:44
  thing.
• 24:45
  Professor Fred Watson: That's. That's correct. Yes, exactly.
• 24:48
  Andrew Dunkley: All right, great question, Michael. Well
• 24:50
  done. Uh, and thanks for sending that one in.
• 24:55
  Okay, We've had a problem here.
• 24:57
  Speaker D: This is Houston.
• 24:58
  Professor Fred Watson: Say again, please. Houston, we've had about.
• 25:00
  Andrew Dunkley: We've had a main B undervolt. Roger, main B
• 25:02
  undervolt. Okay, standby 13. We're looking at
• 25:04
  it. Stay sputs F5.
• 25:07
  Final question today comes from somebody who
• 25:10
  forgot to tell us their name.
• 25:13
  Speaker C: Hi guys. Um, You've been listening to the
• 25:16
  show for many many years. Um,
• 25:19
  I'm a Brit obviously. You've been wondering
• 25:21
  about how to ask a question. I've had several
• 25:24
  questions in the past. Uh, the question I
• 25:26
  have now is is there anything else that I
• 25:29
  haven't found that is going to go and
• 25:32
  observe the sun at such or even at
• 25:35
  a longer thing? Because my favourite
• 25:37
  spacecraft in the world, Parker Solar
• 25:40
  Probe and I think it is
• 25:43
  done such an amazing job and I was just
• 25:46
  wondering if there was anything else that you
• 25:48
  guys knew that might um, be
• 25:51
  more exciting. So there we
• 25:54
  go. Anyway, thank you very much for this. Um,
• 25:56
  the podcast has been fantastic for me. It's
• 25:59
  kept me going through several nights, months
• 26:02
  and years and that was the best
• 26:05
  question I could come up with.
• 26:07
  Andrew Dunkley: Fair enough. And uh, it's a good one. Uh,
• 26:09
  thanks for sending it in. Don't know your
• 26:11
  name but um, we know where you are. We know
• 26:14
  where you are. Um,
• 26:17
  now he mentioned the Parker Solar Probe. Um,
• 26:20
  that's also uh, achieved the fastest speed by
• 26:22
  a human made object ever I think.
• 26:26
  Um, fairly recently. Uh, there are
• 26:28
  several uh, probes out there
• 26:31
  sort of doing the solar thing. The Solar
• 26:34
  Orbiter which is an ESA mission. There's also
• 26:36
  the Solar Dynamics Dynamics Observatory,
• 26:38
  although I don't is it, is it up there or is
• 26:41
  it on Jordy I can't remember. It's a NASA
• 26:42
  observatory, uh, soho,
• 26:46
  uh, the Solar and Heliospheric Observatory.
• 26:49
  Uh, stereo, uh that's we've talked about
• 26:52
  stereo. It's two spacecraft um,
• 26:54
  orbiting the sun from different angles uh, so
• 26:57
  that they can get a um, 360 degree view
• 27:00
  of the star. And the JAXA
• 27:02
  NASA mission.
• 27:07
  Professor Fred Watson: That's right, yeah.
• 27:08
  Andrew Dunkley: Uh, which is focusing on magnetic fields. Um,
• 27:11
  so they're the ones that I'm aware of at the
• 27:13
  moment. Are they more exciting? I Space in
• 27:15
  their individual ways they've all got
• 27:17
  something different to contribute. So they'd
• 27:19
  all be exciting in one way or another.
• 27:24
  Professor Fred Watson: Um, that's right. And uh, there are some
• 27:27
  upcoming ones as well that I think qualify
• 27:29
  for being exciting. Um, but
• 27:32
  just backstory of the Parker Solar
• 27:34
  Probe, uh, the reason why it goes so fast is
• 27:37
  that it comes so close to the sun and
• 27:39
  anything that's in orbit, um, and an
• 27:41
  elliptical orbit is at its fastest when it's
• 27:44
  at uh, perihelion, the nearest point to the
• 27:46
  sun. Uh and in fact that near point
• 27:49
  um takes it through the
• 27:52
  sun's inner corona. Uh and I think
• 27:54
  I read um, this last week
• 27:57
  it had its um. Was it its 28th
• 28:01
  uh, flyby of the solar
• 28:03
  corona? I think that's right.
• 28:05
  Um, uh
• 28:08
  yes. Uh, on the 11th of
• 28:11
  June it completed its
• 28:14
  28th close approach to the sun, sorry on the
• 28:17
  8th of June, uh matching its record distance
• 28:20
  of 3.8 million miles or about
• 28:23
  5 million kilometres, something like that. So
• 28:26
  that's why that's exciting because it gets
• 28:28
  fried nearly every time it goes that close to
• 28:30
  the sun. But I think there are some coming up
• 28:33
  which are uh, um, also pretty exciting.
• 28:36
  Uh, ESA's Vigil spacecraft
• 28:40
  uh, which will launch in 2031.
• 28:42
  That's going to be at the L5 point. Andrew.
• 28:45
  So it's one of the two Lagrange
• 28:48
  points which shares the same orbit as the
• 28:51
  Jordy and it's actually the one behind the
• 28:53
  Jordy in terms of uh, the
• 28:55
  way the Jordy uh circulates in its orbit. So
• 28:58
  it's 60 degrees behind the Jordy
• 29:02
  Uh and what it sees from that vantage point
• 29:04
  is a different view of the sun because it
• 29:07
  sees uh, the side of the sun
• 29:10
  that is invisible to us but is about
• 29:13
  to become visible as the sun rotates.
• 29:16
  So it will see the sun
• 29:19
  uh several days before
• 29:22
  it moves into our view from
• 29:25
  Jordy So what it's doing is giving you
• 29:27
  advanced warning of all the kind of
• 29:30
  activity that we see on the sun's surface.
• 29:32
  Uh, coronal Massey, ejections,
• 29:35
  solar flares, all of that stuff will be
• 29:38
  visible before it comes uh, into
• 29:41
  our uh, um before it points
• 29:43
  towards the Jordy Uh where some of
• 29:46
  these things could actually have an effect on
• 29:48
  us. On Jordy Um, there's
• 29:51
  ah, something called Prober
• 29:54
  3 which is two satellites
• 29:57
  and this I think is pretty exciting as well.
• 30:00
  Uh they're in Jordy orbit but they uh,
• 30:03
  basically give you an artificial eclipse
• 30:06
  in space. Oh wow. So um, you have
• 30:09
  one which is shaped like a disc
• 30:12
  in as much as you can see it in the direction
• 30:14
  towards the sun that sits in front of the
• 30:17
  sun, the other one's some distance behind.
• 30:20
  Uh, and the two of them uh
• 30:23
  let you see the inner corona of the sun. So
• 30:25
  that's also exciting. Uh,
• 30:29
  I uh, don't know when that's uh, planned to
• 30:31
  be launched but I Beg your pardon, that is
• 30:33
  already in orbit. Uh, that's one that's
• 30:35
  already in orbit. It's a very
• 30:38
  highly precise formation, um,
• 30:41
  pair of satellites. I think we've talked
• 30:43
  about it before actually now I've come to
• 30:46
  remember.
• 30:46
  Andrew Dunkley: Sounds familiar.
• 30:47
  Professor Fred Watson: Yeah. And then once again another uh
• 30:51
  there's a NASA, a set of satellites called
• 30:53
  Punch, uh four satellites um
• 30:56
  which basically are ah in what's called a sun
• 30:59
  synchronous orbit. They're always uh
• 31:01
  moving along the line between day and night
• 31:05
  and again that will give us uh
• 31:07
  3D observations because there are four
• 31:10
  satellites more than and they're in different
• 31:12
  places uh there's going to be an Indian one
• 31:15
  I think there's all sorts of really exciting
• 31:18
  stuff coming up up for solar astronomy which
• 31:20
  we'll uh learn from a whole new fleet of
• 31:23
  spacecraft. So once again uh, I'm sorry I
• 31:26
  don't know your name but it's a good question
• 31:28
  and a great one to ask indeed.
• 31:30
  Andrew Dunkley: Uh and not forgetting all the land based
• 31:32
  solar observatories and one that You've been
• 31:35
  that um I visited there last year or
• 31:37
  drove past it anyway was on uh Mount Tedi
• 31:40
  in Tenerife. Yes it's
• 31:44
  a solar observatory, the Gregor
• 31:47
  Professor Fred Watson: Observatory I think, I think that's right,
• 31:49
  yes. And there's also the Daniel K Inouye
• 31:51
  telescope uh which is on the summit of
• 31:53
  Haleakala on Maui uh we
• 31:56
  got married in front of it Marnie and I um
• 31:59
  and uh that's the biggest solar telescope at
• 32:01
  the moment. Uh I think there's a bid to try
• 32:03
  and build a bigger one but the Daniel uh K
• 32:05
  inoue telescope, a 4 metre telescope looking
• 32:08
  at the sun. So we've got the most exquisite
• 32:10
  detail on the sun's surface coming from the
• 32:12
  telescope.
• 32:13
  Andrew Dunkley: You can't keep China out of it because
• 32:15
  they've got the Chinese Large Solar Telescope
• 32:17
  um which is um quite a big
• 32:20
  one and the list is long. There are many,
• 32:22
  many on the, on the actual
• 32:25
  surface of the planet that are dedicated to
• 32:27
  solar observatory so and for the record
• 32:30
  the Parker solar probe uh achieved the
• 32:33
  fastest speed by any human made
• 32:36
  object on 24th December 2024
• 32:39
  when at perihelion it achieved a speed
• 32:42
  of 430,000
• 32:45
  miles per hour which is
• 32:48
  692,000 kilometres hour
• 32:51
  and uh, yes everyone's been arrested now
• 32:56
  Professor Fred Watson: quite right too, yes
• 32:58
  Andrew Dunkley: um, that's, that's, that's extraordinary
• 33:00
  speed though. It really is um, quite an
• 33:03
  amazing feat but um, thanks for sending it
• 33:06
  uh in your question uh whoever you are but
• 33:08
  we know where you live uh and that brings us
• 33:11
  to the end. Fred thank you very much.
• 33:13
  Professor Fred Watson: Pleasure Andrew good uh to talk again and
• 33:16
  we'll speak again soon.
• 33:17
  Andrew Dunkley: We will indeed. Professor Fred Watson,
• 33:20
  Astronomer at large. And if you would like to
• 33:22
  send a question in for our Q A episodes,
• 33:24
  please do. Just, uh, go to our website, space
• 33:27
  nutspodcast.com spacenuts IO
• 33:30
  Click on the AMA link at the top where you
• 33:33
  can send text and audio questions and we'll
• 33:35
  do our very best to ignore them, but then
• 33:38
  again, we'll probably answer them. Uh,
• 33:40
  sometimes we get people that double up and
• 33:42
  triple up. And, uh, so if we don't answer
• 33:45
  your question, it's probably because someone
• 33:46
  else already beat you to the punch. But, uh,
• 33:48
  you know, I do my best to go through them and
• 33:50
  make sure we don't miss anybody. But, um,
• 33:53
  yes, I try to share it around. So it's, um,
• 33:56
  different people all the time as well. So
• 33:58
  there's all these bureaucratic things I've
• 34:00
  got to deal with. And, uh, thanks also
• 34:03
  to Hugh in the studio.
• 34:04
  Uh, now, our last, um, question came from,
• 34:07
  um, a fellow who said he was looking into
• 34:10
  how to ask a question. And that got Hugh
• 34:13
  thinking, so he went to look it up and he's
• 34:15
  still trying to figure out how to ask a
• 34:17
  question. That's why he couldn't be with us
• 34:19
  today. And from me, Andrew Dunkley. Thanks
• 34:21
  for your company. We'll see you on the next
• 34:22
  episode of Space Nuts. Bye. Bye.
• 34:26
  You're listening to the Space Nuts podcast,
• 34:30
  available at Apple Podcasts, Spotify,
• 34:33
  iHeartRadio or your favourite podcast
• 34:35
  player. You can also stream on demand at
• 34:38
  Bitesz.com.
• 34:39
  Professor Fred Watson: Um, this has been another quality podcast
• 34:41
  production from Bitesz.com.
• 34:43
  Andrew Dunkley: Um,