# Galactic Queries: Black Hole Lifespans, Lunar Impacts & Sun-Seeking Missions

An episode of [Space Nuts: Astronomy Insights & Cosmic Discoveries](https://invisiblenetwork.ai/podcast/1080090608), 20 Jul 2026, 35 min.

Audio: https://dts.podtrac.com/redirect.mp3/pscrb.fm/rss/p/op3.dev/e/api.spreaker.com/download/episode/73064405/galactic_queries_black_hole_lifespans_lunar_impacts_sun_seeking_missions.mp3

Sponsor Link: NordVPN - Secure your online presence with our exclusive offer for Space Nuts listeners. Check out www.nordvpn.com/spacenuts for details. In this engaging Q&A episode of Space Nuts, Andrew Dunkley and Professor Fred Watson dive into listener inquiries that span the cosmos. From the intriguing concept of black hole evaporation to the mysteries of Jupiter's atmosphere and the latest on the Artemis 2 mission, this episode is packed with fascinating insights and scientific discussions. In this episode: - The mechanics of black hole evaporation and how cosmic microwave background radiation affects their lifespan. - An exploration of Jupiter's thin atmosphere and how it compares to the dense atmospheres of moons like Titan and planets like Venus. - Insights into the Artemis 2 mission and the implications of visual observations of meteorite impacts on the moon's far side. - A look ahead at upcoming solar missions and the cutting-edge technology being deployed to study our sun. - The significance of cosmic rays and their impact on human perception in space. Resources & Links: - \[Parker Solar Probe\](https://www.nasa.gov/content/parker-solar-probe) - NASA's mission to study the sun's outer atmosphere. - \[Artemis Program\](https://www.nasa.gov/specials/artemis/) - NASA's initiative to return humans to the moon. - \[The Cosmic Microwave Background\](https://map.gsfc.nasa.gov/universe/uni_cmb.html) - Understanding the remnants of the Big Bang. - \[Titan and Its Atmosphere\](https://solarsystem.nasa.gov/planets/titan/overview/) - NASA's insights into Saturn's largest moon. Join Andrew and Fred Watson as they unravel the complexities of space science and encourage curiosity about the universe. Don't forget to send in your questions for future episodes! Become a supporter of this podcast: https://www.spreaker.com/podcast/space-nuts-astronomy-insights-cosmic-discoveries--2631155/support. (00:00) Andrew Dunkley takes audience questions on this week's Space Nuts (02:53) If black holes are colder than cmb, how much does this lengthen (09:12) Fred: Does Jordy have an unusually thin atmosphere for a rocky planet (10:48) Titan has a much higher atmospheric pressure than our own planet Jordy (17:16) Michael from Switzerland claims Artemis 2 astronauts saw meteorite flashes on moon (24:55) Houston has had a main B undervolt problem (25:07) Final question today comes from somebody who forgot to tell us their name (34:04) Andrew Dunkley: Thanks for your company. Bye. You're listening to the Space Nuts podcast

## Transcript

[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,

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