In this engaging episode of Space Nuts, hosts Heidi Campo and Professor Fred Watson embark on a fascinating journey through listener questions that probe the depths of astrophysics and cosmology. From the nature of neutron stars to the mysteries of gravitational waves, this episode is brimming with insights that will expand your understanding of the universe.
Episode Highlights:
- Neutron Stars vs. Pulsars: The episode opens with a thought-provoking question from Dean in Washington, D.C., asking whether all neutron stars are pulsars. Fred clarifies the distinction between these celestial objects, explaining that not all neutron stars emit pulsations, with many having “retired” from their energetic displays.
- Gravitational Waves and Mass Conversion: New listener Ben dives into the complexities of merging neutron stars and the resulting gravitational waves. Fred explores the intricate relationship between mass and energy, shedding light on how these cosmic events contribute to our understanding of the universe's fabric.
- Galactic Mysteries and the Big Bang: Craig from Marimbula raises intriguing questions about the implications of massive galaxies observed by the James Webb Space Telescope. Fred discusses how these findings fit into current cosmological models and the significance of the Big Bang theory in understanding the universe’s age.
- Meteors on Mars: Listener Martin from Bloomington, Indiana, wonders about the appearance of meteors on Mars compared to Earth. Fred explains how the thin Martian atmosphere affects meteor visibility and the likelihood of impacts, offering insights into the unique conditions on the Red Planet.
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Stay curious, keep looking up, and join us next time for more stellar insights and cosmic wonders. Until then, clear skies and happy stargazing.
(00:00) Welcome to Space Nuts with Heidi Campo and Fred Watson
(01:20) Discussion on neutron stars and pulsars
(15:00) Exploring gravitational waves from merging neutron stars
(25:30) Implications of massive galaxies and the Big Bang
(35:00) What meteors would look like on Mars
For commercial-free versions of Space Nuts, join us on Patreon, Supercast, Apple Podcasts, or become a supporter here: https://www.spreaker.com/podcast/space-nuts-astronomy-insights-cosmic-discoveries--2631155/support
00:00:00 --> 00:00:03 Heidi Campo: Welcome back to another fun and exciting
00:00:03 --> 00:00:06 Q and A episode of Space Nuts.
00:00:06 --> 00:00:09 I am your host for this episode, Heidi Campo. And
00:00:09 --> 00:00:12 joining me is Professor Fred Watson,
00:00:12 --> 00:00:13 astronomer at large.
00:00:13 --> 00:00:16 Voice Over Guy: 15 seconds. Guidance is internal.
00:00:16 --> 00:00:19 10, 9. Ignition
00:00:19 --> 00:00:22 sequence star space nuts. 5, 4, 3,
00:00:22 --> 00:00:25 2. 1. 2, 3, 4, 5, 5, 4,
00:00:25 --> 00:00:27 3, 2, 1. Space nuts
00:00:27 --> 00:00:29 Astronauts report. It feels good.
00:00:30 --> 00:00:33 Heidi Campo: Fred, how are you on this fine day?
00:00:33 --> 00:00:35 Professor Fred Watson: I'm very well, thanks, Heidi.
00:00:36 --> 00:00:39 And, um, I'm, um, delighted to see you again
00:00:39 --> 00:00:41 because it is always a pleasure to take our, uh, listener
00:00:41 --> 00:00:44 questions, uh, especially on a nice fine.
00:00:45 --> 00:00:47 What is here in Australia, Winter's morning?
00:00:48 --> 00:00:51 Uh, uh, it's a sunny day, as we
00:00:51 --> 00:00:54 often get in wintertime in Sydney.
00:00:55 --> 00:00:58 Heidi Campo: Well, you'll be delighted to hear that it has
00:00:58 --> 00:01:00 finally stopped raining here in Houston, Texas.
00:01:01 --> 00:01:04 The sun has come back out, starting to forget what it looked
00:01:04 --> 00:01:06 like. But, um, we will be going
00:01:06 --> 00:01:09 camping this weekend, so I'm looking forward to that. I
00:01:09 --> 00:01:12 will, um, report back to you guys next week what, uh, the
00:01:12 --> 00:01:14 weather from West Texas looks like.
00:01:16 --> 00:01:19 Professor Fred Watson: If you get any great photos, Heidi, we should try and
00:01:19 --> 00:01:22 post them on the Space Nuts website.
00:01:22 --> 00:01:25 Heidi Campo: Oh, maybe I'll have to bring my telescope, uh, and do some
00:01:25 --> 00:01:28 astrophotography out there. Actually, that's. I'm gonna, I
00:01:28 --> 00:01:29 am gonna do that.
00:01:30 --> 00:01:33 Um, and speaking of the United States, all of our
00:01:33 --> 00:01:36 questions are from the U.S. this, uh,
00:01:36 --> 00:01:38 this, this go around. And our first question
00:01:38 --> 00:01:41 comes from dean from Washington,
00:01:41 --> 00:01:44 D.C. doesn't get any more United States
00:01:44 --> 00:01:46 than that. Dean asks,
00:01:47 --> 00:01:49 um, are all neutron stars
00:01:49 --> 00:01:52 pulsars in? If so, is it not
00:01:52 --> 00:01:55 theoretically possible that a collapsing star has
00:01:55 --> 00:01:58 so little angular momentum that it doesn't pulse?
00:01:58 --> 00:02:01 If not, what else can a neutron
00:02:01 --> 00:02:01 star be?
00:02:03 --> 00:02:06 Professor Fred Watson: So, um, yeah, this, this, this
00:02:06 --> 00:02:09 question has a simple answer. No.
00:02:11 --> 00:02:13 Um, thank you, Dean.
00:02:13 --> 00:02:13 Heidi Campo: Moving on.
00:02:14 --> 00:02:17 Professor Fred Watson: I might elaborate on that a little bit. Um,
00:02:18 --> 00:02:21 not all neutron stars are pulsars. And actually, look, I'm
00:02:21 --> 00:02:23 going to take a direct quote from a NASA
00:02:23 --> 00:02:26 website called Ask an Astrophysicist.
00:02:26 --> 00:02:29 Doesn't come any better than that. Um,
00:02:30 --> 00:02:32 because I love the opening of this little
00:02:32 --> 00:02:35 answer. Most neutron stars in the
00:02:35 --> 00:02:38 universe are old enough and tired enough
00:02:38 --> 00:02:40 that they are no longer pulsars.
00:02:40 --> 00:02:43 Um, and let me just interrupt
00:02:43 --> 00:02:46 that quote by reminding us what
00:02:46 --> 00:02:49 a neutron star and a pulsar is. A neutron star
00:02:49 --> 00:02:52 is this highly collapsed object. It used to be a star,
00:02:52 --> 00:02:55 but now we're seeing the collapsed core of the star,
00:02:55 --> 00:02:57 only a few kilometers or miles across.
00:02:58 --> 00:03:01 Uh, uh, what makes it a pulsar is
00:03:01 --> 00:03:04 when it's spinning rapidly, uh,
00:03:04 --> 00:03:07 and beaming radiation from its magnetic Poles.
00:03:07 --> 00:03:10 So they behave just like a lighthouse, flashing, uh,
00:03:11 --> 00:03:14 on and off, pulsing, uh, as the name implies.
00:03:14 --> 00:03:17 So, uh, Dean's question is a good one. Are all
00:03:17 --> 00:03:19 neutron stars pulsars? And they're not.
00:03:20 --> 00:03:23 And as the NASA website says,
00:03:23 --> 00:03:25 most of them are old enough and tired enough that they're no longer
00:03:25 --> 00:03:28 pulsars. They've stopped spinning. Uh, and
00:03:28 --> 00:03:31 just one, uh, further sentence on
00:03:31 --> 00:03:34 that, which I think is quite illuminating. A recent paper
00:03:34 --> 00:03:37 estimates 1000 million, what we call
00:03:37 --> 00:03:40 a billion, normally 1000 million old
00:03:40 --> 00:03:43 neutron stars in our galaxy in. Even though
00:03:43 --> 00:03:46 the known number of pulsars, uh,
00:03:46 --> 00:03:48 is only about 1000. So
00:03:49 --> 00:03:52 there are many, many more neutron stars
00:03:52 --> 00:03:55 that don't pulsate than there are that do
00:03:55 --> 00:03:58 just because they've lost all their rotational energy.
00:03:58 --> 00:04:01 So, a great question from Dean, um, sent
00:04:01 --> 00:04:04 me to NASA's website, which is always a good thing.
00:04:05 --> 00:04:07 Heidi Campo: I think they know the right answer.
00:04:08 --> 00:04:09 Professor Fred Watson: One would hope so. Yeah.
00:04:10 --> 00:04:13 Heidi Campo: I saw a T shirt in their gift shop a few weeks ago when
00:04:13 --> 00:04:15 I was there, and it just. The Earth is round. We
00:04:15 --> 00:04:17 checked. Love NASA.
00:04:18 --> 00:04:21 I thought that was kind of cute and cheeky.
00:04:21 --> 00:04:22 Professor Fred Watson: Yeah.
00:04:23 --> 00:04:25 Heidi Campo: Our next question is from Ben,
00:04:26 --> 00:04:29 who is actually a new listener. So thank
00:04:29 --> 00:04:32 you, Ben, for writing in. This is, uh, so much
00:04:32 --> 00:04:34 fun. Ben says, I came across the
00:04:34 --> 00:04:37 podcast last week and I've been zooming through
00:04:37 --> 00:04:40 it. I love the content. Thank you.
00:04:41 --> 00:04:44 And then Ben goes on to say, I've got a question, and hopefully you
00:04:44 --> 00:04:46 haven't already answered it on the roughly
00:04:46 --> 00:04:49 450 episodes I haven't had
00:04:49 --> 00:04:52 a chance to listen to yet. Um, but he
00:04:52 --> 00:04:55 says one, when neutron stars and
00:04:55 --> 00:04:58 or black holes merged to
00:04:58 --> 00:05:01 produce gravitational waves, they lose mass,
00:05:01 --> 00:05:03 which gets converted to energy, which
00:05:03 --> 00:05:06 comprises. Which comprises of the gravitational
00:05:06 --> 00:05:09 wave. But how does that conversion work?
00:05:09 --> 00:05:12 Specifically? I'm thinking of a binary
00:05:12 --> 00:05:14 neutron star system merging,
00:05:15 --> 00:05:18 since my understanding is that the mass of the
00:05:18 --> 00:05:21 neutron is quite consistent across the universe.
00:05:21 --> 00:05:24 A reduction in mass would imply that a
00:05:24 --> 00:05:26 reduction in the number of neutrons
00:05:26 --> 00:05:29 would imply a reduction in the number of neutrons.
00:05:29 --> 00:05:32 If this small leap of logic holds,
00:05:32 --> 00:05:35 what determines which neutrons get converted
00:05:35 --> 00:05:38 to energy? Are the faded neutrons
00:05:38 --> 00:05:40 extracted evenly from throughout the
00:05:40 --> 00:05:43 merging objects, or is there a region
00:05:43 --> 00:05:46 that seems to be favored? And what
00:05:46 --> 00:05:49 does this process of converting neutrons to
00:05:49 --> 00:05:50 energy look like?
00:05:52 --> 00:05:54 Ben is curious and hungry for answers.
00:05:55 --> 00:05:57 Professor Fred Watson: It's a fabulous question, Ben.
00:05:57 --> 00:06:00 Um, I've got a question for you, Ben, as well. How did you manage to get
00:06:00 --> 00:06:03 through 450 episodes in
00:06:03 --> 00:06:06 a week, less than a week? That
00:06:06 --> 00:06:09 defies, um, probably the laws of physics. I
00:06:09 --> 00:06:11 Think, uh, but that's all right because
00:06:11 --> 00:06:14 apparently uh, merging neutron
00:06:14 --> 00:06:16 stars also apparently derive
00:06:17 --> 00:06:20 um, they, they break the laws of
00:06:20 --> 00:06:23 physics. So um,
00:06:23 --> 00:06:25 Ben, your question, as some of our
00:06:25 --> 00:06:28 listener questions often do because they are so good,
00:06:28 --> 00:06:31 sent me to the World Wide Web.
00:06:31 --> 00:06:34 And the answer to this question is
00:06:36 --> 00:06:38 quite, uh, it's quite subtle and there's
00:06:38 --> 00:06:41 several things going on, partly because
00:06:41 --> 00:06:44 we're dealing with very intense
00:06:44 --> 00:06:47 gravitational fields. Uh, and
00:06:47 --> 00:06:50 um, you know, to answer your question, are
00:06:50 --> 00:06:53 the fated neutrons extracted evenly throughout the
00:06:53 --> 00:06:56 merging objects or is there a
00:06:56 --> 00:06:58 region that seems to be favored, um,
00:06:59 --> 00:07:01 that probably relates to the
00:07:01 --> 00:07:04 event horizon of the neutron stars because
00:07:04 --> 00:07:07 they do have event horizons. Um, and
00:07:07 --> 00:07:10 I don't think I'm capable of answering
00:07:10 --> 00:07:13 that question. Uh, and
00:07:13 --> 00:07:16 in any case it's more subtle than
00:07:16 --> 00:07:19 just um, you know, neutrons getting thrown
00:07:19 --> 00:07:22 away, uh, than what we were, than what
00:07:22 --> 00:07:24 your question might imply. So
00:07:25 --> 00:07:27 I would actually suggest, uh, Ben, that
00:07:27 --> 00:07:29 you have a look uh, online,
00:07:30 --> 00:07:33 uh, ah, at the uh, physics.stackink
00:07:33 --> 00:07:35 exchange.com website,
00:07:36 --> 00:07:37 uh, because
00:07:37 --> 00:07:39 physics.stackexchange.com
00:07:40 --> 00:07:43 has got a uh, very nice set
00:07:43 --> 00:07:45 of question, question very similar to
00:07:45 --> 00:07:48 yours and some quite lengthy answers
00:07:48 --> 00:07:51 that go into some detail, um, and
00:07:52 --> 00:07:54 look at different aspects of this question.
00:07:55 --> 00:07:58 Um, so if you Google energy conversion from
00:07:58 --> 00:08:01 mass to gravitational wave, the, that will take
00:08:01 --> 00:08:04 you to this website and maybe
00:08:04 --> 00:08:07 I can just um, you know, talk about
00:08:08 --> 00:08:11 uh, one of those answers. And that is that
00:08:11 --> 00:08:13 um, if you imagine, uh,
00:08:14 --> 00:08:17 uh, one of the sort of subatomic particles and what
00:08:17 --> 00:08:20 we call an alpha particle, which is the nucleus, a helium
00:08:20 --> 00:08:22 4 nucleus, got two protons, two
00:08:23 --> 00:08:25 neutrons, but its mass
00:08:26 --> 00:08:28 is actually less than the
00:08:28 --> 00:08:31 sum of those protons and neutrons.
00:08:32 --> 00:08:35 And that's because there is something called
00:08:35 --> 00:08:37 binding energy, uh, that's
00:08:37 --> 00:08:40 released when that particle is
00:08:40 --> 00:08:43 formed. And so uh, the
00:08:43 --> 00:08:46 bottom line here is that mass and
00:08:46 --> 00:08:49 energy are uh, highly interchangeable. When you're
00:08:49 --> 00:08:52 talking about the kinds of things, the sort of
00:08:52 --> 00:08:55 extremes that we are looking at in the
00:08:55 --> 00:08:58 case of um, a neutron star, neutron star
00:08:58 --> 00:09:00 collisions. Even in a neutron star doing its thing,
00:09:00 --> 00:09:03 it's still extreme situations. And because
00:09:03 --> 00:09:06 of the relationship that we're all aware of between
00:09:06 --> 00:09:09 mass and energy, E equals MC squared.
00:09:09 --> 00:09:11 That is, uh, why
00:09:12 --> 00:09:14 you know, you've got this
00:09:14 --> 00:09:17 potential to transform what looks
00:09:17 --> 00:09:20 like a mass of a single particle,
00:09:20 --> 00:09:23 uh, into energy, uh, to result
00:09:23 --> 00:09:26 in a lower gravitational mass
00:09:26 --> 00:09:29 for the pair of neutron stars. Sorry, the bottom line
00:09:29 --> 00:09:32 here, which I should have said at the beginning, is that often when you've
00:09:32 --> 00:09:35 got this neutron star, neutron star
00:09:35 --> 00:09:37 collision, uh, you Get a
00:09:38 --> 00:09:40 gravitational wave which
00:09:40 --> 00:09:43 essentially, uh, has enough energy
00:09:43 --> 00:09:46 to account for a difference in mass. It's not
00:09:46 --> 00:09:49 just the sum of the two neutron stars that come together.
00:09:49 --> 00:09:51 There is a mass loss as well, which we see as the
00:09:51 --> 00:09:54 gravitational wave. And this is one of the mechanisms
00:09:54 --> 00:09:57 that causes that. So have a look Ben, at
00:09:57 --> 00:10:00 that webpage. Uh, and if you still
00:10:00 --> 00:10:03 don't get it, ask us again, uh, and
00:10:03 --> 00:10:06 I'll have another shot at it. But it is a really
00:10:06 --> 00:10:08 interesting question and a good one too.
00:10:09 --> 00:10:11 Um, um, got me thinking yesterday. I
00:10:11 --> 00:10:14 was worrying all day about this
00:10:14 --> 00:10:17 question, uh, trying to take my mind off the
00:10:17 --> 00:10:20 root canal treatment that I was having at the dentist. At
00:10:20 --> 00:10:21 the same time.
00:10:24 --> 00:10:26 Heidi Campo: I also think of particle, uh, physics while I'm at the dentist.
00:10:27 --> 00:10:30 Professor Fred Watson: It's the only thing to do really, isn't it?
00:10:30 --> 00:10:33 Heidi Campo: So I actually, I will give my dentist a shout out.
00:10:33 --> 00:10:36 My dentist, um, was one of my good friends
00:10:36 --> 00:10:39 in, uh, doing my undergrad. And it was kind of cute
00:10:39 --> 00:10:42 because the whole little cohort of us, we
00:10:42 --> 00:10:44 um, started, we were in a powerlifting club in
00:10:44 --> 00:10:47 my undergrad and uh,
00:10:48 --> 00:10:51 we were just, you know, just a bunch of kids. And now he's
00:10:51 --> 00:10:53 a grown up who's a dentist and we're all doing our
00:10:53 --> 00:10:56 things. One of the other ones went on to be um,
00:10:57 --> 00:11:00 a neurosurgeon. And so I'm like, it's quite a
00:11:00 --> 00:11:03 little brainiac group of strength athletes.
00:11:04 --> 00:11:07 So shout out to, uh, Dr. Gatlin
00:11:07 --> 00:11:10 Marks, dentist at Platinum Dentistry
00:11:10 --> 00:11:13 in Utah. On that's, you know, unprompted.
00:11:14 --> 00:11:16 Not paid for free advertising, but he's great.
00:11:18 --> 00:11:20 Professor Fred Watson: Well, I should advertise mine, shouldn't I?
00:11:22 --> 00:11:24 Nothing like as nice a story, but I won't bother.
00:11:30 --> 00:11:31 Heidi Campo: Space nuts.
00:11:31 --> 00:11:34 Um, well, our next question is an audio question
00:11:35 --> 00:11:38 from Craig and we are going to play that
00:11:38 --> 00:11:40 question for you right now.
00:11:41 --> 00:11:44 Professor Fred Watson: Hi professors, it's Craig down in
00:11:44 --> 00:11:47 sunny Marimbula. Um, I've been
00:11:47 --> 00:11:50 seeing items about James Webb, uh,
00:11:50 --> 00:11:52 seeing really massive galaxies
00:11:53 --> 00:11:56 much bigger than they, than current
00:11:56 --> 00:11:59 cosmology expects. Are we
00:11:59 --> 00:12:01 in an older universe? Could we
00:12:01 --> 00:12:04 tell the difference between a big bang and a supermassive
00:12:04 --> 00:12:07 white hole that's erupted into an existing space
00:12:07 --> 00:12:10 time? They're just an uh,
00:12:10 --> 00:12:13 overactive imagination. I hope you're enjoying your
00:12:13 --> 00:12:14 week. Ciao.
00:12:14 --> 00:12:17 Heidi Campo: All right, that was Craig's, uh, question.
00:12:18 --> 00:12:21 Professor Fred Watson: Craig, the only person asking uh, a
00:12:21 --> 00:12:23 question this week from.
00:12:24 --> 00:12:25 Not from the usa.
00:12:27 --> 00:12:30 Okay, his question about big galaxies,
00:12:30 --> 00:12:33 is it telling us that the universe is older than we think?
00:12:34 --> 00:12:37 Maybe, uh, that's a, it's a nice way of Thinking
00:12:37 --> 00:12:39 about it, um, except that
00:12:40 --> 00:12:42 we, we still,
00:12:43 --> 00:12:45 you know, all the evidence points
00:12:46 --> 00:12:48 to the
00:12:49 --> 00:12:51 universe having a beginning which
00:12:52 --> 00:12:54 was 13.8 billion years ago,
00:12:54 --> 00:12:57 um, which, um, we think was,
00:12:57 --> 00:13:00 um, the result of a, an event called the Big Bang,
00:13:01 --> 00:13:03 an explosive event. Uh, we
00:13:04 --> 00:13:07 believe that's the case partly because of what we observe today.
00:13:07 --> 00:13:10 But we can also still see the flash of that Big Bang
00:13:10 --> 00:13:13 by the fact that the light has taken 13.8 billion
00:13:13 --> 00:13:16 years to get to us. So, um, it's
00:13:16 --> 00:13:19 very hard to see how, uh,
00:13:19 --> 00:13:21 if the universe was older than that Big Bang,
00:13:24 --> 00:13:26 how galaxies would survive that
00:13:27 --> 00:13:29 explosive event. Um,
00:13:29 --> 00:13:32 so you know what, um,
00:13:33 --> 00:13:35 Craig's question is about is,
00:13:35 --> 00:13:38 uh, are, uh, there galaxies that are older than we think the
00:13:38 --> 00:13:40 universe is? And
00:13:41 --> 00:13:44 it defies logic. It's like saying,
00:13:44 --> 00:13:47 um. And in fact, for a while, this was one of the problems
00:13:47 --> 00:13:50 with the Big Bang theory. People thought, uh, the
00:13:50 --> 00:13:52 um, planets,
00:13:54 --> 00:13:57 uh, stars and atoms were actually older
00:13:57 --> 00:13:59 than the measurement of the age of the universe that
00:13:59 --> 00:14:02 we got. And that was one of the problems for the Big Bang theory,
00:14:03 --> 00:14:05 uh, which was, uh, only really resolved in
00:14:05 --> 00:14:08 the 60s, 1950s and 60s.
00:14:09 --> 00:14:11 Um, so
00:14:11 --> 00:14:14 I think that's still a step of logic that
00:14:14 --> 00:14:17 we're not prepared to dismiss,
00:14:17 --> 00:14:19 uh, that yes, there is that, um,
00:14:20 --> 00:14:23 the Big Bang does mark the start of, uh, the
00:14:23 --> 00:14:26 formation of galaxies and the galaxies in the
00:14:26 --> 00:14:29 universe. Um, I have a colleague and uh,
00:14:29 --> 00:14:32 friend, uh, who's a, uh, very distinguished
00:14:32 --> 00:14:35 astronomer in the uk, Richard Ellis. And
00:14:35 --> 00:14:37 he is absolutely. He's a
00:14:37 --> 00:14:40 cosmologist. He's somebody who looks at the history of the universe,
00:14:40 --> 00:14:43 very interested in the history of the early universe.
00:14:43 --> 00:14:46 He is absolutely certain, uh,
00:14:46 --> 00:14:49 that those galaxies that we can see that
00:14:49 --> 00:14:52 do look bigger and older than what we expected them to
00:14:52 --> 00:14:54 be, uh, that they do not defy,
00:14:55 --> 00:14:58 uh, conventional cosmology, that we can still,
00:14:59 --> 00:15:01 um, you know, work out
00:15:01 --> 00:15:04 theoretical models that would allow those galaxies still to
00:15:04 --> 00:15:07 be young, even though they look more
00:15:07 --> 00:15:10 advanced in years than we thought they
00:15:10 --> 00:15:13 would be. So, uh, it's all about
00:15:13 --> 00:15:16 our understanding of galaxy formation rather than
00:15:16 --> 00:15:18 having the cosmology wrong, rather than having,
00:15:19 --> 00:15:22 uh, the age of the universe wrong. So,
00:15:22 --> 00:15:25 a good suggestion, uh, uh, but I think
00:15:25 --> 00:15:27 we are still stuck with trying to understand how
00:15:27 --> 00:15:30 these galaxies got so big so quickly.
00:15:31 --> 00:15:33 Heidi Campo: And stuck is what it is. Sometimes
00:15:35 --> 00:15:38 that's what I get excited about with space. There's
00:15:38 --> 00:15:40 so many questions that have to be answered.
00:15:41 --> 00:15:43 Other sciences are so defined, but space
00:15:44 --> 00:15:46 is infinite for us to figure out.
00:15:48 --> 00:15:50 Professor Fred Watson: Okay, we checked all four systems and.
00:15:50 --> 00:15:53 Heidi Campo: Dealing with the space nets, our, um,
00:15:53 --> 00:15:55 our last Question is from another curious
00:15:55 --> 00:15:58 listener. Mark from Bloomington,
00:15:58 --> 00:16:01 Indiana says hello there.
00:16:01 --> 00:16:04 What might meteors look like to a person on the
00:16:04 --> 00:16:07 surface of Mars or Venus, if that were possible.
00:16:08 --> 00:16:11 The planets are at uh, extremes of atmospheric
00:16:11 --> 00:16:13 density. But carbon dioxide is the primary
00:16:13 --> 00:16:16 aspheric gas for each.
00:16:17 --> 00:16:19 The primary aspheric gas for each. And there is very little
00:16:19 --> 00:16:22 oxygen present compared to Earth and to
00:16:22 --> 00:16:25 each other. Would meteors appear brighter or dimmer,
00:16:26 --> 00:16:28 different colors travel faster or slower,
00:16:28 --> 00:16:31 more or less likely to be seen given the thick or
00:16:31 --> 00:16:34 thin clouds and the uh, clouds altitudes
00:16:34 --> 00:16:37 more or less likely to strike the surface. Thanks
00:16:37 --> 00:16:40 for any insights or even guesses.
00:16:42 --> 00:16:45 Professor Fred Watson: I think we've been sprung here, Heidi. People have realized that we
00:16:45 --> 00:16:47 just take guesses at these things.
00:16:50 --> 00:16:51 Um, so it's uh,
00:16:52 --> 00:16:55 it's another great question. You know, we uh, this is,
00:16:55 --> 00:16:58 I think none of the questions that we've had today have
00:16:58 --> 00:17:01 ever come in before. Uh, maybe,
00:17:01 --> 00:17:04 maybe people have been speculating about the um,
00:17:04 --> 00:17:07 the mystery of these early galaxies. But this is a
00:17:07 --> 00:17:10 great question. What would meteorites, sorry, what would meteors
00:17:10 --> 00:17:13 look like, uh, to somebody. Let's
00:17:13 --> 00:17:16 just stick with Mars for now because that's the easier
00:17:16 --> 00:17:19 one to deal with. I um, think Venus will
00:17:19 --> 00:17:22 be a problem because the atmosphere is so thick, uh,
00:17:22 --> 00:17:25 so opaque that uh, you probably wouldn't see any
00:17:25 --> 00:17:26 meteors at all just because,
00:17:28 --> 00:17:30 you know, there's very little transparency in the
00:17:30 --> 00:17:33 atmosphere. Mars however, is different. Uh,
00:17:33 --> 00:17:35 it does have clouds, but not as many as we have here on
00:17:35 --> 00:17:38 Earth. Uh, let's get to the easy
00:17:38 --> 00:17:41 question, the easy part of this question, uh,
00:17:41 --> 00:17:42 which is, um,
00:17:44 --> 00:17:47 Query. Are they more or less likely to
00:17:47 --> 00:17:50 strike the surface? And the answer is they're more likely
00:17:50 --> 00:17:53 because Mars's atmosphere is much thinner. It's less than
00:17:53 --> 00:17:56 1% of the pressure of the Earth's atmosphere. That
00:17:56 --> 00:17:58 means that um, it's uh, more likely
00:17:58 --> 00:18:01 that a meteoritic object would
00:18:02 --> 00:18:04 survive its passage through the atmosphere to
00:18:04 --> 00:18:07 reach the ground. Um, and we do find
00:18:07 --> 00:18:10 meteorites on Mars. There are many examples that the
00:18:10 --> 00:18:13 uh, various Mars rovers have found meteorites on
00:18:13 --> 00:18:16 the planet Mars. A uh, meteorite is
00:18:16 --> 00:18:19 a meteor that's got as far as landing on the, on the
00:18:19 --> 00:18:22 ground, but what they would look like in
00:18:22 --> 00:18:25 the uh, in the sky, uh,
00:18:26 --> 00:18:28 uh, doesn't really have that much to do with what the
00:18:28 --> 00:18:30 constituents of the atmosphere are. Uh,
00:18:31 --> 00:18:34 uh, because what you see when you see a
00:18:34 --> 00:18:37 meteor, a shooting star is the fact
00:18:37 --> 00:18:39 that it is simply um,
00:18:40 --> 00:18:42 it's being um, heated up to
00:18:42 --> 00:18:45 incandescence. It's not burning in the
00:18:45 --> 00:18:48 sense that things burn
00:18:48 --> 00:18:51 in the presence of oxygen. Uh, and that I think is the
00:18:51 --> 00:18:52 thrust of, uh, Mark's question.
00:18:53 --> 00:18:56 But what you're seeing is this thing shooting through the
00:18:56 --> 00:18:59 atmosphere. It is meeting a gas. Uh,
00:18:59 --> 00:19:02 the gas is providing some resistance, but
00:19:02 --> 00:19:04 also a lot of friction on the outside of this
00:19:04 --> 00:19:07 particle or stone or rock or baseball, whatever
00:19:07 --> 00:19:10 it is that's coming in, uh, whatever size it is that's coming,
00:19:10 --> 00:19:13 coming in. And that's what causes the brightness
00:19:13 --> 00:19:15 of the meteorites being flashed into
00:19:15 --> 00:19:18 incandescence by its speed rather than a
00:19:18 --> 00:19:21 chemical reaction taking place. Um, that
00:19:21 --> 00:19:24 would, um, make uh, that much difference. Although
00:19:24 --> 00:19:27 certainly we do see evidence of the oxygen
00:19:27 --> 00:19:30 in the light of some of these. So meteors on
00:19:30 --> 00:19:33 Mars would look similar to what they do on
00:19:33 --> 00:19:36 Earth. There's some dispute
00:19:36 --> 00:19:39 because the atmosphere of Mars, whilst
00:19:39 --> 00:19:41 it's also much thinner than Earth's atmosphere, is
00:19:41 --> 00:19:44 distributed differently. You know, uh,
00:19:45 --> 00:19:47 the way in which it falls off in pressure as you go
00:19:47 --> 00:19:50 up in height, uh, is different from
00:19:50 --> 00:19:53 what it is on Earth. So that might mean that the
00:19:53 --> 00:19:56 height at which meteors start to glow
00:19:56 --> 00:19:59 as they come through the surface, sorry, come through
00:19:59 --> 00:20:02 the atmosphere of Mars might be different.
00:20:02 --> 00:20:05 And if they were lower, if they were burning up lower down
00:20:05 --> 00:20:08 in the atmosphere, then they would look a bit brighter than they
00:20:08 --> 00:20:11 do here on Earth. If they were burning up higher in the
00:20:11 --> 00:20:14 atmosphere, they would, uh, look a bit
00:20:14 --> 00:20:16 fainter. And it's not quite clear which of those
00:20:16 --> 00:20:19 is the case. Uh, there's some dispute among
00:20:20 --> 00:20:23 the. Certainly the things I've read about whether they
00:20:23 --> 00:20:25 will be brighter or fainter, but they will be much the same.
00:20:26 --> 00:20:29 So, uh, we hope that maybe one
00:20:29 --> 00:20:32 day when, uh, astronauts are
00:20:32 --> 00:20:35 exploring, uh, but not colonizing
00:20:35 --> 00:20:38 Mars, uh, that they might send us
00:20:38 --> 00:20:41 back reports of meteors that they've seen in the night skies of
00:20:41 --> 00:20:44 Mars. And maybe you'll hear about it on Space notes.
00:20:45 --> 00:20:48 Heidi Campo: Maybe so. And it is my understanding that that
00:20:48 --> 00:20:51 is one. I mean, there's so many concerns with Moon
00:20:51 --> 00:20:53 to Mars missions. And a potential Mars colony
00:20:54 --> 00:20:57 is it's not as safe. Our atmosphere does
00:20:57 --> 00:20:59 surprisingly a lot to protect us. And that is,
00:21:00 --> 00:21:02 um, in a lot of student design
00:21:02 --> 00:21:05 competitions that is something they're really
00:21:05 --> 00:21:08 asking for students to look at is, hey, how can we
00:21:08 --> 00:21:11 protect potential analogs
00:21:11 --> 00:21:14 or colonies or any other assets we put
00:21:14 --> 00:21:16 on Mars? How do we protect those from these
00:21:16 --> 00:21:19 constant, um, impacts? And
00:21:19 --> 00:21:22 ah, that is really kind of an interesting question right now.
00:21:22 --> 00:21:25 And that's not really my wheelhouse. But, um,
00:21:25 --> 00:21:27 people in the engineering world are, um.
00:21:28 --> 00:21:30 There's a lot of fun things for them. To do with those
00:21:30 --> 00:21:31 projects.
00:21:32 --> 00:21:35 Professor Fred Watson: Indeed. That's right. Look, it's a different world
00:21:35 --> 00:21:38 from ours. Everything's
00:21:38 --> 00:21:41 different. Uh, radiation, meteoritic
00:21:41 --> 00:21:44 bombardment, all of those things. Low pressure, low gravity,
00:21:45 --> 00:21:48 different world and a lot to think about if
00:21:48 --> 00:21:51 we are ever going to have humans walking on Mars.
00:21:52 --> 00:21:55 Heidi Campo: All right, Fred. Well, ah, this has been
00:21:55 --> 00:21:58 another fantastic Q and A episode. I
00:21:58 --> 00:22:01 always, I love the way you answer these questions. I
00:22:01 --> 00:22:04 feel like, uh, every time we write in,
00:22:04 --> 00:22:07 I feel like each one of us has an opportunity
00:22:07 --> 00:22:09 to be a, uh, collaborator with you and
00:22:09 --> 00:22:12 gets to experience what it's like to be on
00:22:12 --> 00:22:15 this intellectual journey together. So keep
00:22:15 --> 00:22:18 sending in your amazing questions. You guys are,
00:22:18 --> 00:22:21 you guys are half of the brilliance of this show. So
00:22:21 --> 00:22:22 thank you so much.
00:22:22 --> 00:22:24 Professor Fred Watson: That's right. I agree there
00:22:24 --> 00:22:27 wholeheartedly, Heidi. At least half. In fact, maybe more than
00:22:27 --> 00:22:28 that.
00:22:30 --> 00:22:33 Heidi Campo: Excellent. Well, thank you everybody to listening to
00:22:33 --> 00:22:36 another episode of Space Nuts. We will catch
00:22:36 --> 00:22:37 you next time.
00:22:37 --> 00:22:39 Professor Fred Watson: Sounds great. Thanks again, Heidi.
00:22:40 --> 00:22:42 Andrew Dunkley: Hi, Fred. Hi, Huw. Hi,
00:22:42 --> 00:22:43 Heidi.
00:22:43 --> 00:22:46 It's Andrew from the southwestern
00:22:46 --> 00:22:49 Indian Ocean. We've just finished a seven day crossing
00:22:49 --> 00:22:51 of the Indian Ocean and stopped yesterday at
00:22:52 --> 00:22:54 the beautiful island country of
00:22:54 --> 00:22:57 Mauritius. And it's winter there, but
00:22:57 --> 00:22:59 the temperature was in the
00:22:59 --> 00:23:02 uh, mid to high 20s. So,
00:23:02 --> 00:23:05 um, yeah, if that's winter, I'll take it. It's been
00:23:05 --> 00:23:08 beautiful. The seas were quite smooth after our, uh,
00:23:08 --> 00:23:11 treacherous rounding of south, uh, southern
00:23:11 --> 00:23:13 Australia. Uh, but now that we've left Mauritius,
00:23:13 --> 00:23:16 we're heading into, into some heavy seas as we
00:23:16 --> 00:23:19 move towards the Cape of Good Hope and
00:23:19 --> 00:23:22 then come up the other side of Africa. But
00:23:22 --> 00:23:25 Mauritius was absolutely beautiful, lovely, uh,
00:23:25 --> 00:23:27 people, interesting story behind Mauritius.
00:23:28 --> 00:23:30 It's a, an island that was discovered by
00:23:31 --> 00:23:34 Arabian, uh, sailors. Uh, it was unoccupied,
00:23:34 --> 00:23:37 so they moved in and uh, of course they brought their
00:23:37 --> 00:23:40 slaves with them. Um, somewhere along the
00:23:40 --> 00:23:43 line they handed us over to, um,
00:23:43 --> 00:23:46 the Dutch and the Portuguese. Uh, the
00:23:46 --> 00:23:48 Dutch kind of decimated everything they possibly
00:23:48 --> 00:23:51 could. My wife's half Dutch, so I've got
00:23:51 --> 00:23:54 to be careful what I say. But, uh, they killed off the
00:23:54 --> 00:23:57 dodo bird, they destroyed most of the
00:23:57 --> 00:23:59 forests. Uh, they killed off the
00:23:59 --> 00:24:02 native giant turtles. Uh,
00:24:02 --> 00:24:05 so, um, yeah, nothing like that is there today.
00:24:05 --> 00:24:08 But then, uh, the French moved in and they
00:24:08 --> 00:24:11 stayed there for a very long time until they were tipped out by the British.
00:24:11 --> 00:24:14 And the British held sovereignty over Mauritius until
00:24:14 --> 00:24:17 independence late last century. Beautiful
00:24:17 --> 00:24:20 country, very rugged volcanic
00:24:20 --> 00:24:23 landscape. Uh, saw, uh,
00:24:23 --> 00:24:25 the volcano at the top that still, uh, exists. It's
00:24:25 --> 00:24:28 dormant. It hasn't erupted for a long, long time. And I hope it doesn't because
00:24:28 --> 00:24:31 it's got houses all over it. Uh, but, um,
00:24:31 --> 00:24:34 just a, just a beautiful landscape. They speak French
00:24:35 --> 00:24:38 and English as their predominant, uh, languages.
00:24:38 --> 00:24:41 But the, but the, the native people who are originally, uh,
00:24:41 --> 00:24:44 you know, from the slaves of South Africa speak
00:24:44 --> 00:24:47 French Creole. So it's really, really
00:24:47 --> 00:24:50 interesting mix of people. But, uh, a lovely country
00:24:50 --> 00:24:53 and, and very, very much worth
00:24:53 --> 00:24:55 visiting. Uh, and a very big Hindu
00:24:56 --> 00:24:58 population as well. And so we
00:24:59 --> 00:25:01 visited, visited a Hindu temple and the sacred waters
00:25:01 --> 00:25:04 that were discovered by a Hindu many, many years ago,
00:25:05 --> 00:25:08 uh, where people were blessing children and uh,
00:25:09 --> 00:25:11 walking through the waters, which are just as sacred as the
00:25:11 --> 00:25:14 Ganges, apparently. Uh, and um,
00:25:14 --> 00:25:17 there was a little monument there to the sun
00:25:17 --> 00:25:20 and the planets. So, uh, there was a little
00:25:20 --> 00:25:22 astronomical connection,
00:25:23 --> 00:25:24 uh, while I was there.
00:25:24 --> 00:25:27 Anyway, that's where we're up to. Next stop will be
00:25:27 --> 00:25:30 Cape Town. It's going to take us five days of sailing to get
00:25:30 --> 00:25:32 there, so I'll report on that next time.
00:25:33 --> 00:25:36 So hope all is going well with Space Nuts. See you soon.
00:25:37 --> 00:25:40 Professor Fred Watson: You've been listening to the Space Nuts. Podcast,
00:25:41 --> 00:25:44 available at Apple Podcasts, Spotify,
00:25:44 --> 00:25:47 iHeartRadio or your favorite podcast
00:25:47 --> 00:25:50 player. You can also stream on demand at bitesz.com
00:25:51 --> 00:25:54 This has been another quality podcast production from
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