Space Nuts Episode 494: Radiation Around Jupiter, Light Refraction, and Brown Dwarfs
Join Andrew Dunkley and Professor Jonti Horner in this thought-provoking Q&A edition of Space Nuts, where they tackle a variety of intriguing questions from our listeners. From the complexities of radiation surrounding Jupiter to the effects of light refraction in space, and the mysteries of brown dwarfs, this episode is packed with insights that will expand your understanding of the cosmos.
Episode Highlights:
- Radiation Around Jupiter: Fenton from Minnesota dives deep into the types of radiation emitted by Jupiter and the charged particles from its volcanic moon Io. Jonti explains the implications for spacecraft navigating this hazardous environment and how these particles interact with Jupiter's magnetic field.
- Light Refraction and Redshift : Kerry from Mount Gambier wonders about the impact of gas clouds on light refraction and redshift. Jonti clarifies how light behaves when passing through these clouds and reassures listeners that the redshift measurements remain largely unaffected.
- Brown Dwarfs and Binary Systems: Nigel from Brisbane asks whether binary brown dwarfs are destined to collide. Jonti discusses the dynamics of binary systems and the various factors that could lead to such an event, while also exploring the potential for merging to create a star.
- Marsquakes and Planetary Structure: Buddy poses a fascinating question about the origins of marsquakes and whether Mars could eventually break apart. Jonti unpacks the geological processes at play on Mars and the role of Jupiter in shaping the asteroid belt.
For more Space Nuts, including our continually updating newsfeed and to listen to all our episodes, visit our website. (https://www.spacenutspodcast.com/about)
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 - Introduction to the episode and topics
02:15 - Discussion on radiation around Jupiter and its implications
10:30 - Light refraction and its impact on redshift
18:00 - Insights into binary brown dwarfs and potential collisions
26:45 - Marsquakes and the internal structure of Mars
30:00 - Closing thoughts and listener engagement
✍️ Episode References
Jupiter's Magnetosphere
https://en.wikipedia.org/wiki/Magnetosphere_of_Jupiter
Marsquakes Research
https://mars.nasa.gov/marsquake/
Brown Dwarfs and Binary Systems
https://en.wikipedia.org/wiki/Brown_dwarf
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Episode link: https://play.headliner.app/episode/25500436?utm_source=youtube
00:00:00 --> 00:00:02 hi there thanks for joining us this is a
00:00:02 --> 00:00:05 Q&A episode of space nuts that's me that
00:00:05 --> 00:00:08 means there's questions that people ask
00:00:08 --> 00:00:10 and there are answers that I do not give
00:00:10 --> 00:00:12 someone else will do that uh but coming
00:00:12 --> 00:00:14 up we're going to uh we're going to get
00:00:14 --> 00:00:16 to something we plan to do last week but
00:00:16 --> 00:00:19 it just uh it was a big question which
00:00:19 --> 00:00:21 required a lot of effort and a lot of
00:00:21 --> 00:00:23 answers a lot of research we just sort
00:00:23 --> 00:00:26 of ran out of time so we'll get that one
00:00:26 --> 00:00:30 done today uh from Fenton uh car
00:00:30 --> 00:00:32 is asking about the effects of Light by
00:00:32 --> 00:00:35 dust clouds or the effects on light uh
00:00:35 --> 00:00:38 Nigel uh is talking Brown dwarfs and
00:00:38 --> 00:00:41 Patty Mars Quakes that's all coming up
00:00:41 --> 00:00:45 in this edition of Space Nuts 15 seconds
00:00:45 --> 00:00:49 guidance is internal 10 9 ignition
00:00:49 --> 00:00:54 sequence start Space Nuts 5 4 3 2 1 2 3
00:00:54 --> 00:00:58 4 5 5 4 3 2 1 Space Nuts as the nuts
00:00:58 --> 00:01:01 reported feels good joining us again is
00:01:01 --> 00:01:04 uh Professor jonty Horner who is a
00:01:04 --> 00:01:06 professor of astrophysics at the
00:01:06 --> 00:01:07 University of Southern Queensland a
00:01:07 --> 00:01:09 horrible part of the world but
00:01:09 --> 00:01:10 somebody's got to live there haven't
00:01:10 --> 00:01:12 they jonty absolutely it's a tragedy
00:01:12 --> 00:01:14 it's glorious here at the minute but we
00:01:14 --> 00:01:16 could do with a bit of rain that said
00:01:16 --> 00:01:17 given the amount of rain that's
00:01:17 --> 00:01:19 happening elsewhere in Australia I'm
00:01:19 --> 00:01:20 probably glad that we're not getting
00:01:20 --> 00:01:22 that yes much much further north than
00:01:22 --> 00:01:25 you are uh up around um near North
00:01:25 --> 00:01:27 Queensland Townsville area it's it's
00:01:27 --> 00:01:30 been bucketing down and they've had some
00:01:30 --> 00:01:32 big floods big FL get my head around the
00:01:32 --> 00:01:34 concept of getting two meters of rain in
00:01:34 --> 00:01:38 a couple of days yeah I can't yeah um I
00:01:38 --> 00:01:40 mean a big rain for us is 80 millimeters
00:01:40 --> 00:01:44 in an hour yeah that's a big rain uh I
00:01:44 --> 00:01:46 think the biggest I've ever experienced
00:01:46 --> 00:01:48 here was 200 millimeters over a weekend
00:01:49 --> 00:01:50 yeah that was some years ago and that
00:01:50 --> 00:01:53 caused big floods across the area but uh
00:01:53 --> 00:01:55 yeah the the the the numbers they're
00:01:55 --> 00:01:58 talking up there are astronomical and
00:01:58 --> 00:02:01 um thoughts go to everybody
00:02:01 --> 00:02:04 affected uh now um we should get
00:02:05 --> 00:02:07 straight into Fenton's question because
00:02:07 --> 00:02:09 it's a big one and we'll be back in
00:02:09 --> 00:02:11 about two or three hours once he's
00:02:11 --> 00:02:14 finished hey fando this is Fenton uh
00:02:14 --> 00:02:17 speaking to you from St Paul Minnesota
00:02:17 --> 00:02:19 in the US on the other side of the
00:02:19 --> 00:02:22 planet I got some questions for you
00:02:22 --> 00:02:25 today about radiation now right now we
00:02:25 --> 00:02:27 have spacecraft that are underway to
00:02:27 --> 00:02:29 Jupiter and there's a lot of fretting
00:02:29 --> 00:02:31 about what going to happen and how to
00:02:31 --> 00:02:34 get them to avoid radiation blasting off
00:02:34 --> 00:02:37 Jupiter so we have three types of
00:02:37 --> 00:02:40 radiation alpha beta and gamma if you
00:02:40 --> 00:02:42 wish I'll leave that up to you to
00:02:42 --> 00:02:44 explain that to the audience my question
00:02:44 --> 00:02:46 to you here is what type of radiation is
00:02:46 --> 00:02:48 that that's coming off of Jupiter is it
00:02:48 --> 00:02:51 just the alpha particles other words
00:02:51 --> 00:02:56 just protons hydrogen atoms uh now here
00:02:56 --> 00:03:00 we go on to IO now IO is also on
00:03:00 --> 00:03:02 blasting off particles from its surface
00:03:02 --> 00:03:06 as a result of it being volcanic so I
00:03:06 --> 00:03:09 guess that means uh we have these charg
00:03:09 --> 00:03:11 particles coming off do you want to also
00:03:11 --> 00:03:13 include them in the term of
00:03:13 --> 00:03:16 radiation now it's also interested in
00:03:16 --> 00:03:19 what types of particles they have these
00:03:19 --> 00:03:22 are metals apparently um for example if
00:03:22 --> 00:03:25 it were iron then and if it were charged
00:03:25 --> 00:03:28 then iron can be magnetic and that means
00:03:28 --> 00:03:30 it could possibly be interacting with
00:03:30 --> 00:03:34 the magnetic field of Jupiter so where's
00:03:34 --> 00:03:36 that stuff going is it sticking with all
00:03:36 --> 00:03:40 Jupiter is it heading off Beyond Jupiter
00:03:40 --> 00:03:44 is it landing on some moons and
00:03:44 --> 00:03:46 lastly I want to ask you about a
00:03:46 --> 00:03:48 practical application for this now here
00:03:48 --> 00:03:52 back on Earth we can deposit metal ions
00:03:52 --> 00:03:54 from the gas phase onto substrates and
00:03:54 --> 00:03:56 that has a lot of very useful
00:03:56 --> 00:03:59 applications it's pretty expensive too
00:03:59 --> 00:04:02 so what happens if we put a substrate in
00:04:02 --> 00:04:07 the way in the in in blocking those
00:04:07 --> 00:04:09 metal ions or metal metal
00:04:09 --> 00:04:12 particles that are coming off of AO
00:04:12 --> 00:04:14 could we use that to deposit Metals onto
00:04:15 --> 00:04:16 a
00:04:16 --> 00:04:19 surface just a thought I'd love to hear
00:04:19 --> 00:04:22 what you think about it and what you
00:04:22 --> 00:04:25 where you take my questions have a great
00:04:25 --> 00:04:29 week bye now thank you Fenton uh always
00:04:29 --> 00:04:33 always thinking deeply is is fent and
00:04:33 --> 00:04:35 his questions are always um multifaceted
00:04:35 --> 00:04:37 and that one is no
00:04:37 --> 00:04:40 exception um so he started off talking
00:04:40 --> 00:04:41 about the different types of radiation
00:04:41 --> 00:04:44 and uh which which kind is it coming off
00:04:44 --> 00:04:46 Jupiter yeah I I'll dive through this St
00:04:47 --> 00:04:49 by St but what I will do initially is
00:04:49 --> 00:04:50 and it's a fabulous question there's a
00:04:50 --> 00:04:53 lot in here I'll recommend for the
00:04:53 --> 00:04:54 interested listener who wants to dig
00:04:54 --> 00:04:56 into Jupiter's environment a little bit
00:04:56 --> 00:04:59 more there's a Wikipedia article about
00:04:59 --> 00:05:01 jup magnetosphere which is literally
00:05:01 --> 00:05:03 magnetosphere of Jupiter which is
00:05:03 --> 00:05:05 incredibly thorough and detailed and
00:05:05 --> 00:05:06 goes into some of the things we're about
00:05:06 --> 00:05:09 to discuss in more detail than I will do
00:05:09 --> 00:05:12 now Wikipedia is a fluid resource it can
00:05:12 --> 00:05:14 be changed so your experience may vary
00:05:14 --> 00:05:16 but what would typic typically see is
00:05:16 --> 00:05:19 for astronomy and space subjects they
00:05:19 --> 00:05:20 are not controversial but there's enough
00:05:20 --> 00:05:21 people out there who are incredibly
00:05:21 --> 00:05:23 passionate about it that when an error
00:05:23 --> 00:05:26 Creeps in it gets fixed very quickly so
00:05:26 --> 00:05:27 whilst it's not the most reliable
00:05:27 --> 00:05:29 resource it can be very very good so I
00:05:29 --> 00:05:31 do recommend looking into that if you
00:05:31 --> 00:05:32 want more details on some of the stuff
00:05:32 --> 00:05:33 we'll discuss but I'll try and pick
00:05:34 --> 00:05:36 through the many things Fenton said
00:05:36 --> 00:05:38 there in turn just to try and work
00:05:38 --> 00:05:39 through them if that makes sense and
00:05:39 --> 00:05:40 hopefully that'll be helpful Fenton if
00:05:40 --> 00:05:43 you're listening in firstly when when
00:05:43 --> 00:05:45 you mention three types of radiation
00:05:45 --> 00:05:46 you're talking there about alpha beta
00:05:47 --> 00:05:48 and gamma which are the kinds of
00:05:48 --> 00:05:50 radiation that people talk about being
00:05:50 --> 00:05:52 produced by radioactive
00:05:52 --> 00:05:54 decay and they are three kinds of
00:05:55 --> 00:05:57 radiation but they're not the entirety
00:05:57 --> 00:05:59 of what radiation is and they're
00:05:59 --> 00:06:01 actually different kinds of thing anyway
00:06:01 --> 00:06:04 so Alpha radiation is essentially helium
00:06:04 --> 00:06:07 nuclei so two protons and two neutrons
00:06:07 --> 00:06:10 Su together coming outwards that's F
00:06:10 --> 00:06:12 substantial particle so that's radiation
00:06:12 --> 00:06:14 as a particle it's a particle that's
00:06:14 --> 00:06:16 ejected in this case from a radioactive
00:06:16 --> 00:06:18 process flung outwards with a certain
00:06:18 --> 00:06:21 speed and it's carrying energy from one
00:06:21 --> 00:06:22 place to another in the form of the
00:06:22 --> 00:06:24 particle itself moving at that speed
00:06:24 --> 00:06:29 from A to B beta radiation is electrons
00:06:29 --> 00:06:31 essenti so much less massive typically
00:06:31 --> 00:06:33 traveling much faster that are again
00:06:33 --> 00:06:35 produced by radioactive decay quite
00:06:35 --> 00:06:38 often in other processes alpha particles
00:06:38 --> 00:06:39 are positively charged because they've
00:06:39 --> 00:06:42 got protons in but no electrons beta
00:06:42 --> 00:06:43 radiation is negatively charged because
00:06:44 --> 00:06:46 it's got electrons in and then gamma
00:06:46 --> 00:06:48 radiation is very high energy
00:06:48 --> 00:06:51 electromagnetic radiation so that's the
00:06:51 --> 00:06:53 top end of the electromagnetic spectrum
00:06:53 --> 00:06:55 which also features light that I'm using
00:06:55 --> 00:06:57 to look at Andrew while I waffle away
00:06:57 --> 00:06:59 here and see him nodding unwisely
00:07:00 --> 00:07:02 so there are different bits of radiation
00:07:02 --> 00:07:05 essentially at the very simplest end you
00:07:05 --> 00:07:07 talk about radiation just being energy
00:07:07 --> 00:07:10 being moved from one place to another
00:07:10 --> 00:07:11 and that can be done by waves or
00:07:11 --> 00:07:14 particles so with a very extreme stretch
00:07:14 --> 00:07:15 you could probably argue that when you
00:07:15 --> 00:07:17 go outside and you turn the hose pipe on
00:07:17 --> 00:07:19 and you have a jet and that water is
00:07:19 --> 00:07:20 going from one place to another that's
00:07:20 --> 00:07:22 form of radiation it's energy being
00:07:22 --> 00:07:25 moved from one place to another so
00:07:25 --> 00:07:26 there's a lot of different ways that
00:07:26 --> 00:07:29 energy can be transferred in this way
00:07:29 --> 00:07:32 and light in its many forms is one of
00:07:32 --> 00:07:33 them so that's everything from gamma
00:07:33 --> 00:07:35 rays at the high energy end to radio
00:07:35 --> 00:07:38 waves at low energy end with Optical and
00:07:38 --> 00:07:40 microwave and infrared in the middle
00:07:40 --> 00:07:43 somewhere so there's a lot to radiation
00:07:43 --> 00:07:45 there now there's a couple of things
00:07:45 --> 00:07:47 happening with Jupiter firstly you talk
00:07:47 --> 00:07:49 about the radiation coming off Jupiter
00:07:49 --> 00:07:50 now if you think about Jupiter the
00:07:50 --> 00:07:53 planet itself it's sometimes said that
00:07:53 --> 00:07:56 Jupiter emits more energy than it
00:07:56 --> 00:07:58 receives from the Sun and that's a
00:07:58 --> 00:08:00 leftover from Jupiter's formation from
00:08:00 --> 00:08:01 all the material coming into it the
00:08:01 --> 00:08:03 gravitational relaxation of it
00:08:03 --> 00:08:06 essentially that is energy emitted in
00:08:06 --> 00:08:09 the form of electromagnetic radiation so
00:08:09 --> 00:08:11 light essentially of various wavelengths
00:08:11 --> 00:08:13 it will emit as what we call a black
00:08:13 --> 00:08:15 body so it'll have one particular color
00:08:15 --> 00:08:17 of light that it emits out more strongly
00:08:17 --> 00:08:19 and whether you go Bluer or redder of
00:08:19 --> 00:08:21 that color it will emit more weakly as
00:08:21 --> 00:08:23 you go further away so that's stup to
00:08:23 --> 00:08:25 emitting energy but it's also surrounded
00:08:25 --> 00:08:28 by an incredibly intense magnetic field
00:08:28 --> 00:08:31 much stronger than the Earths so hop to
00:08:31 --> 00:08:33 the Earth briefly one of the challenges
00:08:33 --> 00:08:34 that people face when they fly
00:08:34 --> 00:08:37 satellites around the earth is that
00:08:37 --> 00:08:38 there are these radiation belts around
00:08:38 --> 00:08:40 the earth called the vanum belts and
00:08:40 --> 00:08:42 they were proposed just prior to the
00:08:42 --> 00:08:44 space edge and then detected by the
00:08:44 --> 00:08:45 first
00:08:45 --> 00:08:47 satellites what's going on there is that
00:08:47 --> 00:08:49 the Earth has a magnetic field around it
00:08:49 --> 00:08:51 that interacts with the magnetic field
00:08:51 --> 00:08:52 of the sun and the rest of the solar
00:08:52 --> 00:08:54 system and we've got this area around
00:08:55 --> 00:08:57 the earth called magnetosphere and the
00:08:57 --> 00:08:59 magnetosphere is sculpted and shaped by
00:08:59 --> 00:09:01 what's going on elsewhere now in the
00:09:02 --> 00:09:03 case of the earth you've got solar
00:09:03 --> 00:09:05 radiation in the form of charged
00:09:05 --> 00:09:07 particles as part of the solar wind
00:09:07 --> 00:09:10 buffeting against that magnetosphere
00:09:10 --> 00:09:12 penetrating in and when you have
00:09:12 --> 00:09:14 particles that have charge whether
00:09:14 --> 00:09:16 they're positively or negatively charged
00:09:16 --> 00:09:19 they interact with magnetic fields so
00:09:19 --> 00:09:20 they will follow the direction of the
00:09:20 --> 00:09:22 magnetic field lines and our
00:09:22 --> 00:09:23 magnetosphere Shields us from a lot of
00:09:23 --> 00:09:25 the radiation like that because it goes
00:09:25 --> 00:09:28 around the earth rather than hitting it
00:09:28 --> 00:09:30 but some of the radiation in the form of
00:09:30 --> 00:09:32 charged particles that penetrates the
00:09:32 --> 00:09:33 magnetic field then gets trapped in the
00:09:33 --> 00:09:35 magnetic field in these belts that we
00:09:35 --> 00:09:38 call the vanan belts which are areas
00:09:38 --> 00:09:39 where you have a lot of charged
00:09:39 --> 00:09:41 particles moving around at high speed
00:09:41 --> 00:09:44 trapped in these belts around the earth
00:09:44 --> 00:09:46 between a few hundred and a few tens of
00:09:46 --> 00:09:48 thousands kilometers above the Earth's
00:09:48 --> 00:09:50 surface those are areas where if you fly
00:09:50 --> 00:09:53 a spacecraft through there there's a lot
00:09:53 --> 00:09:55 of charged particles crushing into your
00:09:55 --> 00:09:57 spacecraft at high speed that can damage
00:09:58 --> 00:09:59 the electronics to circuitry in
00:09:59 --> 00:10:02 particular is very sensitive to this and
00:10:02 --> 00:10:04 gradually damage your spacecraft and
00:10:04 --> 00:10:06 take it out of operation so that's the
00:10:06 --> 00:10:08 radiation environment around the earth
00:10:08 --> 00:10:09 and they're trying to avoid going
00:10:09 --> 00:10:12 through the VY and belts as a result
00:10:12 --> 00:10:14 Jupiter's the same Jupiter has a much
00:10:14 --> 00:10:17 more intense magnetic field so it can
00:10:17 --> 00:10:19 have a much more significant area of
00:10:19 --> 00:10:21 radiation belts and those radiation
00:10:21 --> 00:10:23 belts correspond roughly with the
00:10:23 --> 00:10:26 location of the large moons particularly
00:10:26 --> 00:10:29 Europa and I so in that area
00:10:29 --> 00:10:31 when you're a spacecraft moving through
00:10:31 --> 00:10:33 there you're moving through a soup of
00:10:34 --> 00:10:35 highspeed charged particles that are
00:10:35 --> 00:10:38 continually bombarding your spacecraft
00:10:38 --> 00:10:40 degrading it damaging it and of course
00:10:40 --> 00:10:42 they're particularly damaging to the
00:10:42 --> 00:10:44 electrical componentry so you want to
00:10:44 --> 00:10:45 spend as little time as you can though
00:10:45 --> 00:10:47 and that's essentially what the concern
00:10:47 --> 00:10:49 is for the scientists who are sending
00:10:49 --> 00:10:52 spacecraft to Jupiter so that's what's
00:10:52 --> 00:10:55 going on there added to that though
00:10:55 --> 00:10:56 you've got the vulcanism from I which
00:10:57 --> 00:10:59 Fenton mentions and F Fenton quite right
00:10:59 --> 00:11:02 I is erupting continuously volcanically
00:11:03 --> 00:11:05 into that radiation environment around
00:11:05 --> 00:11:07 Jupiter adding I think some quotes say
00:11:08 --> 00:11:11 up to 1 kilos per second of new
00:11:11 --> 00:11:13 material into that environment now the
00:11:13 --> 00:11:15 atoms that are launched out of I by this
00:11:15 --> 00:11:18 vulcanism are things like sulfur oxygen
00:11:18 --> 00:11:21 sulfur dioxide all these kind of things
00:11:21 --> 00:11:23 that initially in molecules and atoms
00:11:23 --> 00:11:25 but are very quickly ionized so they
00:11:25 --> 00:11:28 have an electron knocked off colliding
00:11:28 --> 00:11:29 with this charge particle
00:11:29 --> 00:11:31 which suddenly means you've got sulfur
00:11:31 --> 00:11:34 ions oxygen ions sodium ions all
00:11:34 --> 00:11:35 floating around in the magnetic field so
00:11:35 --> 00:11:38 iio is dumping even more charged
00:11:38 --> 00:11:41 particles into that radiation belt those
00:11:41 --> 00:11:43 charged particles from IO incidentally
00:11:43 --> 00:11:45 flow along Jupiter's magnetic field
00:11:45 --> 00:11:48 lines and crash into the Jovian poles
00:11:48 --> 00:11:50 creating hotpots of Aurora so there are
00:11:50 --> 00:11:53 Aurora on Jupiter that are directly
00:11:53 --> 00:11:55 linked to iio and to a lesser extent
00:11:55 --> 00:11:57 europ and ganam you can see them if you
00:11:57 --> 00:11:59 look at Aurora maps of Jupiter that has
00:11:59 --> 00:12:01 spacecraft to C Park so you get this
00:12:01 --> 00:12:04 flux Taurus connecting IO to the poles
00:12:04 --> 00:12:06 of Jupiter which is the charged
00:12:06 --> 00:12:07 particles flowing along the magnetic
00:12:07 --> 00:12:09 field lines and crashing into Jupiter's
00:12:09 --> 00:12:11 poles so that's how io's shipping in
00:12:11 --> 00:12:14 it's just adding more soup to the mix
00:12:14 --> 00:12:17 essentially moving on to the metals been
00:12:17 --> 00:12:19 magnetic I've tried to get through all
00:12:19 --> 00:12:21 the points yeah I just thought it was
00:12:21 --> 00:12:24 fascinating that that there's such an
00:12:24 --> 00:12:25 effect happening around Jupiter unlike
00:12:25 --> 00:12:27 the the like we see similar effects with
00:12:27 --> 00:12:30 the Aurora boralis and Aurora arral but
00:12:30 --> 00:12:34 different reasons um same effect so
00:12:34 --> 00:12:35 you'll have Aurora on Jupiter that would
00:12:35 --> 00:12:37 cause the same way as the Aurora on
00:12:37 --> 00:12:40 Earth but you also have iio europ and
00:12:40 --> 00:12:42 ganam cooking their own Aurora as well
00:12:42 --> 00:12:46 so it's complicated I think yeah is um
00:12:46 --> 00:12:48 with the metals being magnetic there's a
00:12:48 --> 00:12:50 couple of things there to mention you're
00:12:50 --> 00:12:52 entirely right that metals like iron and
00:12:52 --> 00:12:54 nickel can become permanently magnetized
00:12:54 --> 00:12:56 and this is something called pherom
00:12:56 --> 00:12:59 magnetism um now I'm not a specialist on
00:12:59 --> 00:13:01 magnetism by any means and one of the
00:13:01 --> 00:13:02 common jokes in astronomy is if if you
00:13:02 --> 00:13:04 want to ask a question at a conference
00:13:04 --> 00:13:05 it's almost certainly have you
00:13:05 --> 00:13:07 considered magnetic fields and the
00:13:07 --> 00:13:09 answer is almost certainly no because
00:13:09 --> 00:13:11 it's just complicated there's actually a
00:13:11 --> 00:13:14 few types of magnetism that involves
00:13:14 --> 00:13:16 physical materials out there pherom
00:13:17 --> 00:13:18 magnetism is the most famous it's the
00:13:18 --> 00:13:20 one that's easiest to observe with
00:13:20 --> 00:13:23 magnets but that kind of interaction
00:13:23 --> 00:13:25 with magnetic fields is not what we're
00:13:25 --> 00:13:26 talking about here so we're not talking
00:13:27 --> 00:13:29 about solid lumps of a metal interacting
00:13:29 --> 00:13:31 with the magnetic field we're talking
00:13:31 --> 00:13:33 about individual atoms and molecules
00:13:33 --> 00:13:35 that have been ionized and they're
00:13:35 --> 00:13:36 interacting with the magnetic field not
00:13:36 --> 00:13:38 because they are magnetic but because
00:13:38 --> 00:13:40 they're electrically charged and it is a
00:13:40 --> 00:13:41 subtle difference but it's worth
00:13:41 --> 00:13:42 flagging out that there are two
00:13:42 --> 00:13:45 different things there now the practical
00:13:45 --> 00:13:48 application you talk about about having
00:13:48 --> 00:13:49 something there for all this stuff to
00:13:49 --> 00:13:52 smack into is exactly what they're doing
00:13:52 --> 00:13:54 so if you've got your spacecraft with
00:13:54 --> 00:13:55 all this valuable Electronics on it you
00:13:55 --> 00:13:57 want it to live as long as possible at
00:13:57 --> 00:13:59 Jupiter so it costs a lot to get
00:13:59 --> 00:14:01 there and they're doing two things
00:14:01 --> 00:14:03 simultaneously to maximize the lifetime
00:14:03 --> 00:14:06 of these missions the first adds weight
00:14:06 --> 00:14:08 and therefore adds cost but essentially
00:14:08 --> 00:14:10 for EUR up a Clipper the entire
00:14:10 --> 00:14:12 instrument suite and everything that
00:14:12 --> 00:14:15 does the science that they can protect
00:14:15 --> 00:14:17 is enclosed in this hard shell which is
00:14:17 --> 00:14:20 made of about 100 kilograms of titanium
00:14:20 --> 00:14:22 so titanium very dense is like a
00:14:22 --> 00:14:24 protective shield around it I guess
00:14:24 --> 00:14:25 serving much the same role that your
00:14:25 --> 00:14:26 windscreen does when you're driving
00:14:26 --> 00:14:28 through a rainstorm the water hits your
00:14:28 --> 00:14:29 windscreen rather than hitting you in
00:14:29 --> 00:14:32 the face same kind of idea so that's
00:14:32 --> 00:14:33 part of how they're solving it which is
00:14:34 --> 00:14:35 exactly what Fenton was talking about
00:14:35 --> 00:14:38 with having the ions and stuff Splat
00:14:38 --> 00:14:39 into something and cting them
00:14:39 --> 00:14:41 essentially the other thing they do is
00:14:41 --> 00:14:43 linked to bandwidth and this is a
00:14:43 --> 00:14:44 perennial issue in Australia with the
00:14:44 --> 00:14:46 quality of the national Broadband
00:14:46 --> 00:14:48 Network and with things like starlink
00:14:48 --> 00:14:50 you want as much bandwidth as you can to
00:14:50 --> 00:14:52 transmit data around and the bandwidth
00:14:52 --> 00:14:55 you get back from Jupiter is pretty low
00:14:55 --> 00:14:57 because you're so far away basically the
00:14:57 --> 00:14:59 further away You're broadcasting from
00:14:59 --> 00:15:01 the low your bandwidth is and it turns
00:15:01 --> 00:15:04 out that we don't have broadcasting
00:15:04 --> 00:15:06 equipment on these satellites on these
00:15:06 --> 00:15:07 spacecraft strong enough to send back
00:15:07 --> 00:15:10 the data in real time the rate at which
00:15:10 --> 00:15:12 you get data is much higher than the
00:15:12 --> 00:15:14 rate at which you can send it home so
00:15:14 --> 00:15:15 what that means is if you went into
00:15:15 --> 00:15:18 orbit around Europa you would be
00:15:18 --> 00:15:20 gathering data much more quickly than
00:15:20 --> 00:15:21 you can send it back and then when your
00:15:22 --> 00:15:23 spacecraft dies you've lost all of your
00:15:23 --> 00:15:26 data so you want to maximize the amount
00:15:26 --> 00:15:28 of time you can spend Gathering data
00:15:28 --> 00:15:30 that we get back and the way they'
00:15:30 --> 00:15:32 solved that partially is by having the
00:15:32 --> 00:15:34 cladding the protection that titanium
00:15:34 --> 00:15:37 cell but that's why they've opted to
00:15:37 --> 00:15:39 instead of orbiting Europa to move on a
00:15:39 --> 00:15:41 highly elongated orbit around Jupiter
00:15:42 --> 00:15:44 and have flybys because the amount of
00:15:44 --> 00:15:46 data they can Gathering a 1 hour flyby
00:15:46 --> 00:15:47 might take them several days or a week
00:15:47 --> 00:15:49 to broadcast back home if you're just
00:15:49 --> 00:15:51 sat around Europa waiting for that to
00:15:51 --> 00:15:53 happen your space grass getting cooked
00:15:53 --> 00:15:55 but if you move on a highly elongated
00:15:55 --> 00:15:56 orbit around juper you spend most of
00:15:56 --> 00:15:58 your time on an elongated orbit near the
00:15:59 --> 00:16:00 furthest point on let orbit from the
00:16:00 --> 00:16:01 thing you're going around that's when
00:16:01 --> 00:16:03 you move slowest so you can have your
00:16:03 --> 00:16:06 spacecraft duck in for a very fast flyby
00:16:06 --> 00:16:08 then fly back out of the radiation belt
00:16:08 --> 00:16:09 and spend most of its time safe and not
00:16:09 --> 00:16:11 getting cooked while it broadcasts back
00:16:12 --> 00:16:15 to Earth and by doing that you maximize
00:16:15 --> 00:16:16 the amount of time the spacecraft can
00:16:16 --> 00:16:19 live to take data and give it back to
00:16:19 --> 00:16:21 you so you get the maximum yield from
00:16:21 --> 00:16:23 your spacecraft and the shielding just
00:16:23 --> 00:16:27 helps accentuate that so I think Fenton
00:16:27 --> 00:16:28 I've ticked off every point you've made
00:16:29 --> 00:16:30 there I apologize that that was a an
00:16:30 --> 00:16:32 epic wall of ver verbal gibberish from
00:16:33 --> 00:16:34 me but hopefully I've covered everything
00:16:34 --> 00:16:36 with a lot of johy waffle there yes
00:16:36 --> 00:16:40 indeed now well unpacked I will say and
00:16:40 --> 00:16:44 thanks Fenton hope we covered your uh
00:16:44 --> 00:16:47 questions adequately we we strive for
00:16:47 --> 00:16:50 adequacy here at Space Nuts as you know
00:16:50 --> 00:16:51 uh and you are listening to a Q&A
00:16:51 --> 00:16:54 edition of space nuts with Andrew Dunley
00:16:54 --> 00:16:59 and Johny Horner
00:16:59 --> 00:17:03 two one Space Nuts our next question
00:17:03 --> 00:17:07 comes from somebody whose name I can't
00:17:07 --> 00:17:11 find right at the moment but uh oh it's
00:17:11 --> 00:17:14 Kerry from Mount Gambia uh as I
00:17:14 --> 00:17:15 understand it light refracts because the
00:17:15 --> 00:17:18 speed of light in matter EG glass is
00:17:18 --> 00:17:21 slower than in vacuum I also understand
00:17:21 --> 00:17:23 that we judge the distance slage of the
00:17:23 --> 00:17:26 universe uh objects by addressing their
00:17:26 --> 00:17:29 light red shift I therefore prese light
00:17:29 --> 00:17:31 refraction impacts the red
00:17:31 --> 00:17:35 shift uh so the question is do the gas
00:17:35 --> 00:17:39 clouds in space slow light down I.E
00:17:39 --> 00:17:42 impact the red shift if yes how is the
00:17:42 --> 00:17:44 impact of these dust clouds on the red
00:17:44 --> 00:17:47 shift we use for Universal distances uh
00:17:47 --> 00:17:50 allowed for in the determining of the
00:17:50 --> 00:17:54 age of the universe's objects yes it's a
00:17:54 --> 00:17:56 fabulous question and a really good
00:17:56 --> 00:17:59 observation there so the difference here
00:17:59 --> 00:18:01 is going to be that when the light
00:18:01 --> 00:18:03 enters that gas cloud it will slow down
00:18:03 --> 00:18:05 a little bit now it's not very much
00:18:05 --> 00:18:06 because the density of the gas cloud is
00:18:06 --> 00:18:07 incredibly low so it's a barely
00:18:07 --> 00:18:10 perceptible change but when it leaves
00:18:10 --> 00:18:12 again it will speed back up again so
00:18:12 --> 00:18:15 there's no net impact on the red shift
00:18:15 --> 00:18:16 essentially the light coming out of the
00:18:16 --> 00:18:18 gas cloud will be at the same wavelength
00:18:18 --> 00:18:20 it was when it went in even though when
00:18:20 --> 00:18:22 it was going through the gas cloud it
00:18:22 --> 00:18:24 would have been slowed down a bit the
00:18:24 --> 00:18:26 red shift itself is essentially down to
00:18:26 --> 00:18:28 the stretching of the universe that's
00:18:28 --> 00:18:30 kind of how I always envisage it so the
00:18:30 --> 00:18:32 more stretched the light is the redder
00:18:32 --> 00:18:34 it gets and that is an effect that's
00:18:34 --> 00:18:36 independent of the material that it's
00:18:36 --> 00:18:40 going through now what you could imagine
00:18:40 --> 00:18:41 happening is that let's say you know we
00:18:41 --> 00:18:43 were in the middle of a dense gas cloud
00:18:43 --> 00:18:45 at the minute then all of the light
00:18:45 --> 00:18:46 reaching us would be very slightly
00:18:46 --> 00:18:48 shifted to the red but it would only be
00:18:48 --> 00:18:50 a tiny tiny tiny little effect whereas
00:18:50 --> 00:18:52 the red shifts were measuring are much
00:18:52 --> 00:18:53 more substantive and much more
00:18:53 --> 00:18:57 substantial so you are right that the
00:18:57 --> 00:18:58 speed of light changes as it goes
00:18:58 --> 00:19:00 through clouds and in fact and I'm a
00:19:00 --> 00:19:02 little wooly on this so apologies to any
00:19:02 --> 00:19:04 radio astronomers who are listening but
00:19:04 --> 00:19:07 I remember a talk a few years ago that
00:19:07 --> 00:19:09 was looking at supern noi and things
00:19:09 --> 00:19:12 like that and talking about getting a
00:19:12 --> 00:19:15 feel for the amount of gas clouds on our
00:19:15 --> 00:19:18 line of sight to an object where you had
00:19:18 --> 00:19:20 an object that had been lensed so you
00:19:20 --> 00:19:21 had two different images of the same
00:19:21 --> 00:19:23 object coming through different paths to
00:19:23 --> 00:19:26 us and seeing the difference in timing
00:19:26 --> 00:19:28 of a certain event at Radio wavelengths
00:19:28 --> 00:19:30 because one of those paths had gone
00:19:30 --> 00:19:32 through more gas clouds than the other
00:19:32 --> 00:19:33 so you have the same Pulse arriving at
00:19:33 --> 00:19:36 slightly different times because it have
00:19:36 --> 00:19:38 moved slower through the gas clouds so
00:19:38 --> 00:19:40 that's why you do get this effect and I
00:19:41 --> 00:19:42 found that talk fascinating even though
00:19:42 --> 00:19:44 I'll quite happily admit I a lot of it's
00:19:44 --> 00:19:46 lost on me both in time and distance in
00:19:47 --> 00:19:49 the past so it does impact things there
00:19:49 --> 00:19:50 but it doesn't really impact the red
00:19:50 --> 00:19:51 shift because when you leave the gas
00:19:51 --> 00:19:54 cloud you speed back up and also because
00:19:54 --> 00:19:56 the degree of change is very very
00:19:56 --> 00:20:00 small okay there you go um fairly simple
00:20:00 --> 00:20:02 answer to that one and Carrie thanks for
00:20:02 --> 00:20:04 sending it in uh let's go to our next
00:20:04 --> 00:20:07 audio question from
00:20:07 --> 00:20:10 Nigel hi Fred and Andrew this is Nigel
00:20:10 --> 00:20:12 from Brisbane Australia I recently heard
00:20:12 --> 00:20:16 a report on both uh astronomy daily and
00:20:16 --> 00:20:19 um yourselves on Space Nuts it was a
00:20:19 --> 00:20:23 story about a newly discovered binary
00:20:23 --> 00:20:28 brown dwarf uh system discovered uh I
00:20:28 --> 00:20:33 think it was called gisa
00:20:33 --> 00:20:36 299b anyway binary star systems got me
00:20:36 --> 00:20:41 thinking are they destined to collide so
00:20:41 --> 00:20:45 should we expect the two brown dwarves
00:20:45 --> 00:20:48 to um meet and form as
00:20:49 --> 00:20:51 one and the second question is if they
00:20:51 --> 00:20:52 did um
00:20:53 --> 00:20:55 Collide and form one star would they be
00:20:56 --> 00:21:01 big enough in Mass to create one
00:21:01 --> 00:21:04 star okay thanks for taking my question
00:21:04 --> 00:21:07 love the show keep up the good work by
00:21:07 --> 00:21:09 thanks Nel he's just down the road from
00:21:09 --> 00:21:11 you jonty you're not far away at all he
00:21:11 --> 00:21:12 probably could have come in and given
00:21:12 --> 00:21:16 you that question absolutely so lazy of
00:21:16 --> 00:21:20 him um so we're talking about a binary
00:21:20 --> 00:21:24 brown dwarf system and will they Collide
00:21:24 --> 00:21:26 that was the first part of his question
00:21:26 --> 00:21:28 so a few little parts to that and the
00:21:28 --> 00:21:31 answer to that is almost certainly no
00:21:31 --> 00:21:34 but and there's always a but so if you
00:21:34 --> 00:21:36 imagine initially that you had those two
00:21:36 --> 00:21:39 brown dwars orbiting one another totally
00:21:39 --> 00:21:40 separate from the rest of the universe
00:21:41 --> 00:21:43 so nothing else was
00:21:43 --> 00:21:45 interfering then the two would just
00:21:45 --> 00:21:47 continue orbiting as they are
00:21:47 --> 00:21:49 essentially forever because you've got
00:21:49 --> 00:21:51 nothing to dissipate energy to slow them
00:21:51 --> 00:21:53 down to make them spiral
00:21:53 --> 00:21:55 inwards gets a bit more complicated
00:21:55 --> 00:21:58 though in that there are things that can
00:21:58 --> 00:21:59 change the orbits to do with interaction
00:21:59 --> 00:22:01 now these all tend to require things to
00:22:01 --> 00:22:03 be closed together so if the brand wolfs
00:22:03 --> 00:22:05 are really far apart that's pretty much
00:22:05 --> 00:22:06 the end of the story unless there's
00:22:06 --> 00:22:08 something else in the system whose
00:22:08 --> 00:22:11 gravity is perturbing them but let's say
00:22:11 --> 00:22:12 you can bring the objects close enough
00:22:12 --> 00:22:14 together and this isn't just a case for
00:22:14 --> 00:22:16 brown R incidentally it works for other
00:22:16 --> 00:22:19 things as well if you have these objects
00:22:19 --> 00:22:21 rotating and they're closed enough
00:22:21 --> 00:22:23 together they can tidy interact with one
00:22:23 --> 00:22:26 another and their orbits can change as a
00:22:26 --> 00:22:28 result of that tidal interaction and
00:22:28 --> 00:22:30 we've talked about this before with the
00:22:30 --> 00:22:31 fact that the Moon is moving away from
00:22:31 --> 00:22:34 the earth the moon has one face pointed
00:22:34 --> 00:22:35 towards the Earth all the time but the
00:22:35 --> 00:22:37 Earth is slowly spinning slower and
00:22:37 --> 00:22:39 slower and the Moon is moving away as a
00:22:39 --> 00:22:42 result so that's the tidal interaction
00:22:42 --> 00:22:44 between the two acting to change the
00:22:44 --> 00:22:46 orbit of the moon now because the moon's
00:22:46 --> 00:22:48 orbital period is longer than the time
00:22:48 --> 00:22:51 it takes the Earth to rotate that
00:22:51 --> 00:22:53 process is acting to cause the moon to
00:22:53 --> 00:22:55 move away from the earth not towards us
00:22:55 --> 00:22:57 but if you went to Mars the innermost of
00:22:57 --> 00:23:01 Mars is which is furbos is closer to Ms
00:23:01 --> 00:23:03 than that cor rotation speed so furbos
00:23:03 --> 00:23:05 orbits with an orbital period quicker
00:23:05 --> 00:23:08 than Ma's spin R so the tidal
00:23:08 --> 00:23:10 interaction between those is causing fos
00:23:10 --> 00:23:12 to actually slow down in its orbit for
00:23:12 --> 00:23:14 its orbit to get quicker and quicker and
00:23:14 --> 00:23:16 closer and closer and will eventually
00:23:16 --> 00:23:18 cause fobos to crash into Mars while
00:23:18 --> 00:23:20 they'll probably break apart form a ring
00:23:20 --> 00:23:21 and bits of It Will Rain Down On Mars in
00:23:21 --> 00:23:25 20 to 50 million years in the future um
00:23:25 --> 00:23:26 and and if I'm having a brain fat and
00:23:26 --> 00:23:28 it's actually Dem spiraling in my
00:23:28 --> 00:23:30 apologies but I think F boss is the
00:23:30 --> 00:23:31 closer of the two and that's someone
00:23:31 --> 00:23:34 spirling in so you can get these tital
00:23:34 --> 00:23:36 interactions when you're close enough
00:23:36 --> 00:23:38 that can cause the orbit to change but
00:23:38 --> 00:23:41 you'll only move inwards if the orbital
00:23:41 --> 00:23:43 period is shorter than the rotation
00:23:43 --> 00:23:45 period if the orbital period is longer
00:23:45 --> 00:23:47 than the rotation period you'll move the
00:23:47 --> 00:23:48 other way and you'll move
00:23:48 --> 00:23:51 away the final thing that can happen
00:23:51 --> 00:23:54 well another way it can happen is you
00:23:54 --> 00:23:58 see this for evolved Stars so if a star
00:23:58 --> 00:24:00 has a companion and the star gets to the
00:24:00 --> 00:24:02 end of its life and swells up to become
00:24:02 --> 00:24:04 a red giant it can get bigger and then
00:24:04 --> 00:24:06 the companion can be moving through the
00:24:06 --> 00:24:08 gas in the envelope of that other Stell
00:24:08 --> 00:24:09 which provides a headwind and that can
00:24:09 --> 00:24:11 cause it spiraling towards a close
00:24:11 --> 00:24:13 encounter as well now sometimes that
00:24:13 --> 00:24:15 will just lead to one star numbing up
00:24:15 --> 00:24:17 another one and devouring it and that's
00:24:17 --> 00:24:19 all good but sometimes what that leaves
00:24:19 --> 00:24:22 you with is two evolved Stars very close
00:24:22 --> 00:24:24 together and that can be we see with
00:24:24 --> 00:24:25 binary neutron stars binary white
00:24:25 --> 00:24:27 dwarves Partnerships between black holes
00:24:27 --> 00:24:30 and neutron stars all sorts in recent
00:24:30 --> 00:24:31 years there have been all these
00:24:31 --> 00:24:33 detection of gravitational waves from
00:24:33 --> 00:24:35 colliding stars and they're all from
00:24:35 --> 00:24:37 black holes colliding with each other or
00:24:37 --> 00:24:39 neutron stars colliding with each other
00:24:39 --> 00:24:41 and that's because two black holes or
00:24:41 --> 00:24:43 the two neutron stars are very massive
00:24:43 --> 00:24:46 but they're also very close together so
00:24:46 --> 00:24:47 there are effects that are explained in
00:24:48 --> 00:24:49 general relativity and essentially make
00:24:49 --> 00:24:52 my head hurt that cause a loss of energy
00:24:52 --> 00:24:54 from the binary as it radiates away
00:24:54 --> 00:24:57 gravitational waves that causes the
00:24:57 --> 00:25:00 orbits to SP inwards the closer in they
00:25:00 --> 00:25:02 get the more pronounce this effect is so
00:25:02 --> 00:25:04 you get this runaway collapse of the two
00:25:04 --> 00:25:05 orbits and they end up hitting each
00:25:05 --> 00:25:07 other in a big burst of gravitational
00:25:07 --> 00:25:09 waves I think it's unlikely that will
00:25:09 --> 00:25:11 apply to Brown W but that's another way
00:25:11 --> 00:25:14 they could spiral in so coming back out
00:25:14 --> 00:25:16 from that in general if they're quite
00:25:16 --> 00:25:18 far apart there is no risk of them ever
00:25:18 --> 00:25:20 colliding if they're really close
00:25:20 --> 00:25:22 together it's possible now the final bit
00:25:22 --> 00:25:24 about could they turn into a star is all
00:25:24 --> 00:25:27 about the mass you get if you have
00:25:27 --> 00:25:28 enough mass then the temp temperature
00:25:28 --> 00:25:30 and pressure in the car will get in the
00:25:30 --> 00:25:32 car will get high enough for hydrogen
00:25:32 --> 00:25:35 Fusion sta hydrogen to turn to helium
00:25:35 --> 00:25:36 and that's when it will really turn on
00:25:36 --> 00:25:39 as a star now if you had two very
00:25:39 --> 00:25:41 massive brand dwarfs that are reach not
00:25:41 --> 00:25:43 quite massive enough to be a star and
00:25:43 --> 00:25:44 you add them together you'd certainly be
00:25:44 --> 00:25:46 massive enough to be a star and you
00:25:46 --> 00:25:49 might be able to cross that threshold
00:25:49 --> 00:25:51 now we do see some examples of objects
00:25:51 --> 00:25:53 out there that are thought to probably
00:25:53 --> 00:25:55 be cases where two stars have merged and
00:25:55 --> 00:25:57 form a more massive star that looks out
00:25:57 --> 00:26:00 of place and where this all SS in my
00:26:00 --> 00:26:02 mind are these objects called globular
00:26:02 --> 00:26:04 clusters these massive spherical
00:26:04 --> 00:26:06 clusters of stars that are incredibly
00:26:06 --> 00:26:08 old they're among the oldest things in
00:26:08 --> 00:26:10 the galaxy and famous examples in our
00:26:11 --> 00:26:13 Southern Sky things like Omega centor 47
00:26:13 --> 00:26:15 Tani things like this so you've got a
00:26:15 --> 00:26:17 spherical ball of stars held together
00:26:17 --> 00:26:19 under Gravity that is very old and
00:26:19 --> 00:26:21 because those clusters are very old you
00:26:21 --> 00:26:23 don't expect them to have massive blue
00:26:24 --> 00:26:26 stars in them because there's been no
00:26:26 --> 00:26:27 star formation recently and stars that a
00:26:27 --> 00:26:30 massive blue live fast and die up yeah
00:26:30 --> 00:26:32 so they should be gone but there's a
00:26:32 --> 00:26:34 small group of stars that have been
00:26:34 --> 00:26:36 identified called blue strugglers and
00:26:36 --> 00:26:37 the call strugglers because they should
00:26:37 --> 00:26:40 not be there and for a long time there
00:26:40 --> 00:26:41 was puzzlement as to where these have
00:26:41 --> 00:26:43 come from and I think the currently
00:26:43 --> 00:26:45 accepted wisdom is a blue struggler is
00:26:45 --> 00:26:48 what you get when you get two small or
00:26:48 --> 00:26:49 less massive and therefore longer lived
00:26:49 --> 00:26:52 stars that have merged forming a more
00:26:52 --> 00:26:53 massive star that burns brighter and
00:26:53 --> 00:26:55 hotter so you see what looks like a
00:26:56 --> 00:26:58 young hot star that is a product of two
00:26:58 --> 00:27:02 older cool Stars merging so you can get
00:27:02 --> 00:27:04 things that are Stellar size or stellam
00:27:04 --> 00:27:06 mass merging with one another to form a
00:27:06 --> 00:27:09 star but it's unlikely to happen with
00:27:09 --> 00:27:11 any given set of brown
00:27:11 --> 00:27:14 dwars okay yeah I get it actually that
00:27:14 --> 00:27:17 all made perfect sense um actually I saw
00:27:17 --> 00:27:19 a story last or the other day about a
00:27:19 --> 00:27:21 young hot star that didn't win any
00:27:21 --> 00:27:23 Grammys
00:27:23 --> 00:27:25 so need more
00:27:25 --> 00:27:29 hydrogen yes yes um thank you Nigel
00:27:29 --> 00:27:30 hopefully we covered everything with
00:27:30 --> 00:27:32 your brown dwarf
00:27:32 --> 00:27:34 [Music]
00:27:34 --> 00:27:37 analogy okay we check all four systems
00:27:37 --> 00:27:40 and a Space Nuts uh finally a text
00:27:40 --> 00:27:42 question from Patty I I'm going to
00:27:42 --> 00:27:44 assume this is Patty the roof Tyler but
00:27:44 --> 00:27:46 it could be wrong it could be more than
00:27:46 --> 00:27:47 one patty listening to us especially if
00:27:47 --> 00:27:50 it's Ireland but I got a feeling this
00:27:50 --> 00:27:52 this is the Australian version love the
00:27:52 --> 00:27:54 show keep up the great work uh since the
00:27:54 --> 00:27:56 episode on Mars Quakes I've been
00:27:56 --> 00:27:58 thinking about their Origins we know
00:27:58 --> 00:28:00 that the orbits of all the planets are
00:28:00 --> 00:28:02 slow slowly expanding meaning that they
00:28:02 --> 00:28:05 are moving away from the Sun and they're
00:28:05 --> 00:28:09 cooling now given that a molten rock
00:28:09 --> 00:28:12 cools crystals form and the slower it
00:28:12 --> 00:28:14 cools the larger the crystals could it
00:28:14 --> 00:28:16 be possible that the internal structure
00:28:16 --> 00:28:18 of Mars is laced with veins of
00:28:18 --> 00:28:21 crystallizing rock that is fracturing
00:28:21 --> 00:28:24 which um is the instrument for the
00:28:24 --> 00:28:26 Quakes shortly after the Mars Quakes
00:28:26 --> 00:28:28 episode there were reports of the
00:28:28 --> 00:28:30 possibility of water below the surface
00:28:30 --> 00:28:32 of Mars uh this made me think that
00:28:32 --> 00:28:34 perhaps the Quakes may be the result of
00:28:34 --> 00:28:37 liquid water freezing thus expanding and
00:28:37 --> 00:28:39 fracturing the surrounding rock this
00:28:39 --> 00:28:41 thought of the internal structure of
00:28:41 --> 00:28:43 Mars being fractured led me to the
00:28:43 --> 00:28:45 question of is it possible that Mars
00:28:45 --> 00:28:48 could break up and if so is it possible
00:28:48 --> 00:28:51 that this process could uh be the origin
00:28:51 --> 00:28:54 of the asteroid belt uh when another
00:28:54 --> 00:28:57 planet broke up uh as its orbit drifted
00:28:57 --> 00:29:00 further away from the Sun thank you both
00:29:00 --> 00:29:03 and uh thank you to Hugh cheers Patty uh
00:29:03 --> 00:29:06 he's been thinking a lot about this um I
00:29:06 --> 00:29:09 I would suspect that Mars breaking up
00:29:09 --> 00:29:13 would not be likely due to gravity yeah
00:29:13 --> 00:29:16 gravity winds for Mars for yes I figured
00:29:16 --> 00:29:19 that but uh internal movement you know
00:29:19 --> 00:29:21 the the cooling of the planet perhaps or
00:29:21 --> 00:29:24 the expansion of Frozen ice interesting
00:29:24 --> 00:29:26 the there's a lot of interesting stuff
00:29:26 --> 00:29:28 to on Puck here so
00:29:28 --> 00:29:31 the effect of an object cooling causing
00:29:31 --> 00:29:34 some degree of quakes is actually fairly
00:29:34 --> 00:29:36 well established I think now what needs
00:29:36 --> 00:29:38 to be remembered is that most things
00:29:38 --> 00:29:40 when they cool actually contract water
00:29:40 --> 00:29:42 is really unusual in the water ice
00:29:42 --> 00:29:44 that's near zero is bigger than the same
00:29:44 --> 00:29:46 volume of liquid water at the same
00:29:46 --> 00:29:48 temperature for most materials they're
00:29:48 --> 00:29:51 actually smaller the cooler they get um
00:29:51 --> 00:29:53 so what this is led to is on the moon
00:29:53 --> 00:29:55 and on Mercury there are evidence of
00:29:55 --> 00:29:58 very unusual faulting structures which
00:29:58 --> 00:30:00 are thought to be the result of the
00:30:00 --> 00:30:02 Interior Cooling and shrinking and then
00:30:02 --> 00:30:04 you get this cracking of the surface as
00:30:04 --> 00:30:06 the surface tries to drop essentially
00:30:06 --> 00:30:08 and that of course leads to Quakes and I
00:30:08 --> 00:30:10 believe that um quite a number of the
00:30:10 --> 00:30:12 Quakes are DET detected on the moon are
00:30:12 --> 00:30:15 thought to have this kind of origin
00:30:15 --> 00:30:17 you've then got the kind of freeze th
00:30:17 --> 00:30:19 processes that we see you know growing
00:30:19 --> 00:30:21 up in the UK the rods I get pool far
00:30:21 --> 00:30:22 worse than we get here in Queensland
00:30:22 --> 00:30:24 even though all the locals on the
00:30:24 --> 00:30:26 Facebook groups keep complaining about
00:30:26 --> 00:30:28 the Pooles here which always makes me
00:30:28 --> 00:30:30 laugh the reason we get so many potholes
00:30:30 --> 00:30:32 up in the UK is because of free saw so
00:30:32 --> 00:30:34 if you get a very narrow crack and you
00:30:34 --> 00:30:37 get water in it that water then freezes
00:30:37 --> 00:30:39 it becomes ice and it expands which is
00:30:39 --> 00:30:42 unusual like I said water behaves oddly
00:30:42 --> 00:30:43 and that fractures the road so you get
00:30:43 --> 00:30:46 this runaway fracturing of the surface
00:30:46 --> 00:30:48 this on a different scale you also see
00:30:48 --> 00:30:50 in the degradation of rocks in places
00:30:50 --> 00:30:52 like the high alks because as rocks heat
00:30:52 --> 00:30:55 up and cool down they expand and
00:30:55 --> 00:30:57 contract and that leads to cracking and
00:30:57 --> 00:30:58 fracturing
00:30:58 --> 00:31:00 this is an important process
00:31:00 --> 00:31:01 particularly for my favorite meteor
00:31:01 --> 00:31:03 shower the Geminids the Geminids have a
00:31:03 --> 00:31:05 parent object that is fighton which is
00:31:05 --> 00:31:08 often described as a rock Comet and phon
00:31:08 --> 00:31:10 has ridiculous temperature ranges
00:31:10 --> 00:31:11 through its orbit when it's nearest to
00:31:11 --> 00:31:14 Sun it's about 750 degrees when it's
00:31:14 --> 00:31:15 furthest from the sun it's 100 degrees
00:31:15 --> 00:31:17 below freezing and more and that's a
00:31:17 --> 00:31:19 huge range of temperatures over a couple
00:31:19 --> 00:31:22 of years and one of the explanations for
00:31:22 --> 00:31:24 the Gemini me shower is that the rocks
00:31:24 --> 00:31:27 on Fon are persistently being cracked
00:31:27 --> 00:31:29 and fra Ed by this freeze saw attp
00:31:29 --> 00:31:31 process by the heating and cooling and
00:31:31 --> 00:31:33 then the dust gets kicked off the
00:31:33 --> 00:31:34 surface of the asteroid spreading out
00:31:34 --> 00:31:36 into space to give us a debris stream
00:31:36 --> 00:31:38 that we get for the meteor shower so
00:31:38 --> 00:31:42 there is a lot to that there in terms of
00:31:42 --> 00:31:45 the Quakes on Mars I think that a lot of
00:31:45 --> 00:31:47 them are being linked we've got the ones
00:31:47 --> 00:31:49 that are linked to impact so asteroid
00:31:49 --> 00:31:50 hits Mars and marins like a bell and you
00:31:51 --> 00:31:53 get a Mars quick you then have ones that
00:31:53 --> 00:31:54 we talked about before which are linked
00:31:54 --> 00:31:57 to that kind of residual tectonic energy
00:31:57 --> 00:31:58 and the Heat
00:31:58 --> 00:32:00 movement within Mars but I think there
00:32:00 --> 00:32:01 have been suggestions that some of them
00:32:01 --> 00:32:03 are probably also down to the cooling of
00:32:03 --> 00:32:05 the interior and that kind of cracking
00:32:05 --> 00:32:07 and faulting so it is a process that
00:32:07 --> 00:32:09 would come into play
00:32:09 --> 00:32:11 there however it's probably not what
00:32:11 --> 00:32:13 calls the asteroid belt so the asteroid
00:32:13 --> 00:32:15 belt is often portrayed in canoun of
00:32:15 --> 00:32:17 Science Fiction as a planet that was
00:32:17 --> 00:32:19 destroyed and it's probably fairer to
00:32:19 --> 00:32:21 describe it as a planet that never got
00:32:21 --> 00:32:24 to be the total mass of the astroid belt
00:32:24 --> 00:32:25 as we see it now is way less than the
00:32:25 --> 00:32:28 moon but it was more in the past
00:32:28 --> 00:32:30 but Jupiter's the villain here so when
00:32:30 --> 00:32:31 the planets were
00:32:31 --> 00:32:34 forming Jupiter formed quicker because
00:32:34 --> 00:32:35 it's a little bit beyond what we call
00:32:35 --> 00:32:37 the snow line so all the water that's
00:32:37 --> 00:32:39 out there and as we said earlier in the
00:32:39 --> 00:32:41 podcast water is one of the most common
00:32:41 --> 00:32:43 molecules in the universe Jupiter was
00:32:43 --> 00:32:45 Far Enough From the Sun that that water
00:32:45 --> 00:32:46 was Ice whereas in the inner solar
00:32:46 --> 00:32:48 system it was gas so suddenly when
00:32:48 --> 00:32:50 you've got water ice you've got a lot
00:32:50 --> 00:32:51 more solid material to build planets
00:32:52 --> 00:32:54 from so Jupiter grew really quickly and
00:32:54 --> 00:32:57 as it Mass got bigger its gravitational
00:32:57 --> 00:32:58 reach got got more impactful and it
00:32:59 --> 00:33:01 started stirring up the ashid belt that
00:33:01 --> 00:33:04 excitation meant that the average orbits
00:33:04 --> 00:33:06 of the asids were stirred up more and so
00:33:06 --> 00:33:07 instead of the collisions between them
00:33:07 --> 00:33:09 being gentle enough to stick together
00:33:09 --> 00:33:10 they entered a range where the
00:33:10 --> 00:33:11 collisions are destructive instead
00:33:11 --> 00:33:13 they're cliding hard enough to smash
00:33:13 --> 00:33:16 apart so Jupiter Abridged the formation
00:33:16 --> 00:33:18 of a planet in that region by stirring
00:33:18 --> 00:33:20 things up so much that they couldn't
00:33:20 --> 00:33:22 Collide and acret anymore so the Astro
00:33:22 --> 00:33:24 Bell isn't so much a planet that broke
00:33:24 --> 00:33:27 up as a planet that never got to form
00:33:27 --> 00:33:29 and that's all thanks to Jupiter doing
00:33:29 --> 00:33:33 its thing and stirring everything up so
00:33:33 --> 00:33:34 I think we've covered everything pabas
00:33:34 --> 00:33:36 there I hope we've covered everything
00:33:36 --> 00:33:38 past there but yeah there a lot lot of
00:33:38 --> 00:33:40 good stuff in there I might just add
00:33:40 --> 00:33:42 that some of the earth uh some of the
00:33:42 --> 00:33:45 Mars Quakes that have being detected are
00:33:45 --> 00:33:48 also being put down to meteorite strikes
00:33:48 --> 00:33:50 yes so they have the asteroids hitting
00:33:50 --> 00:33:51 it make it ring like a bell and that was
00:33:52 --> 00:33:53 part of the reason we put the science
00:33:53 --> 00:33:54 Moment On Mars in the first place was to
00:33:54 --> 00:33:58 deter these things yeah okay hey there
00:33:58 --> 00:34:00 you go thanks Patty great question um
00:34:00 --> 00:34:01 good to hear from you and don't forget
00:34:01 --> 00:34:03 if you've got a question for us for our
00:34:03 --> 00:34:06 Q&A episodes please go to our website
00:34:06 --> 00:34:08 and send them in uh it's as simple as
00:34:08 --> 00:34:11 going to SPAC nuts podcast.com and
00:34:11 --> 00:34:13 clicking on the little AMA thing at the
00:34:13 --> 00:34:16 top and if you want to send us a text
00:34:16 --> 00:34:18 question you can do that or you can send
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00:34:20 --> 00:34:21 device with a microphone that's all you
00:34:21 --> 00:34:23 need and don't forget to tell us who you
00:34:23 --> 00:34:26 are and where you're from jonty thank
00:34:26 --> 00:34:27 you so much for answering all of those
00:34:27 --> 00:34:29 questions questions I'm going to make
00:34:29 --> 00:34:30 you do it again next week it's always
00:34:31 --> 00:34:32 pleasure it's good fun thank you for
00:34:32 --> 00:34:35 having me thank you Johnny uh Professor
00:34:35 --> 00:34:37 johy Horner from the University of
00:34:37 --> 00:34:40 Southern Queensland and um look Hugh in
00:34:40 --> 00:34:42 the studio was a noow again today now a
00:34:42 --> 00:34:46 lot of people ask us if Hugh is real I'm
00:34:46 --> 00:34:49 starting to think you might be right
00:34:49 --> 00:34:52 that he doesn't exist yeah and from me
00:34:52 --> 00:34:54 Andrew Dunley thanks to your company
00:34:54 --> 00:34:56 catch you on the very next episode of
00:34:56 --> 00:34:58 Space Nuts bye-bye
00:34:58 --> 00:35:00 sputs you'll be listening to the Space
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