Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / #391: Chasing 'Oumuamua: The Interstellar Pursuit and the Pancake Planets Puzzle

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#391: Chasing 'Oumuamua: The Interstellar Pursuit and the Pancake Planets Puzzle · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Hi, thanks for joining us on another episode of Space Nuts. My name
0:03
is Andrew Dunkley, your host. Hope you're well. Coming up this week,
0:08
we are going to look at a potential plan to catch the space Doogie.
0:13
Yes, they're going to get down and dirty and try and chase this
0:17
thing down. This was an exo asteroid known as Moor that passed through our
0:24
solar system a few years ago. Now they've been to talk about trying to
0:28
catch it. Well, now they think they've got a plan. We're also
0:31
going to look at planet formation. It looks like planets form in different ways
0:37
than we thought. We'll discuss that. Get your m and ms ready.
0:41
That's all coming up on this episode of Space Nuts. Fifteen seconds in Channel
0:48
ten nine ignition Squench Space Nuts SI or three two Space Nuts as it meels
1:00
good and joining me as always to talk about all of those things, and
1:04
probably a lot more, because that's what happens sometimes. Is Professor Fred what's
1:08
an astronomer at Large? Hello Fred Ill Andrew. I'm good to talk to
1:14
you. I understand my audio. It's not brilliant at the moment, but
1:18
maybe we can work around that. Well, just press on regardless. I'll
1:23
do the radio thing and just pretend nothing's wrong. But yeah, we are
1:27
having some technical issues. We seem to swap one week, it's meeting next
1:32
week. Get to you one day, one day we will both have a
1:34
seamless presentation. No no, but not today, not today. No.
1:42
Okay, let's get straight down to business, because this is a rather exciting
1:48
story, and it carries on from a story we did a few years ago
1:51
when it was realized that an exo asteroid passed the planet, passed through our
1:57
Solar system. In fact, it was passed us before we discovered it,
2:00
and there's been all sorts of theories as to what it is, one theory
2:05
being that it was the remnants of an alien spaceship, and others saying it's
2:09
probably the shed off section of a planet. Whatever it was, it did
2:14
not come from our Solar System. It came from somewhere else. But now
2:20
there's talk of maybe putting a mission together to catch it. Now. I
2:25
thought when we talked about this once before, Fred, it was thought impossible.
2:29
But now they've done the maths, maths with an as for your Americans,
2:35
what's the story it is? So it's I think this is a refinement
2:40
actually of something that was proposed almost immediately after the mission. Sorry, the
2:51
object flew through the Solar system first, first messenger from afar, a Hawaiian
2:57
word, because it was discovered I think by punstar upon Haliakola on the island
3:01
of Maui. So it was found in I think it was October twenty seventeen.
3:07
Realized that its velocity was too high for it to have been anything to
3:10
do with the Solar System. It was already sort of passed its closest approach
3:15
to the Sun by the time it was discovered and zoomed off into the white
3:20
blue yonder. That's something like I don't know this, Yeah, I can't
3:23
remember the speed. It's thirty or forty kilometers per second. It's very fast.
3:27
So that prompted a number of a number of speculations about what it was,
3:36
and that the most, you know, the most rigorous detail we have
3:42
of it is that it's an odd shape because it's like curve. As it
3:45
tumbled around, it's like curve went up and down. It was the first
3:47
thought to be a cigar or of red stick or whatever you thought it might
3:53
have been. Andrew without going into any detail. Something something shape, like
3:57
that. Yes, that's right, but work suggested that a better fit came
4:01
from something in the shape of a pancake tumbling end over end, and that
4:06
led to the fact that it's red in color, which is what you get
4:12
if you put something in deep space for a long time, because the cosmic
4:15
rays bake it to a sort of reddish color. And so and that fits
4:20
a bill because it is expected this might have been trolling through space for you
4:25
know, several million years since it left its parent system wherever that is.
4:30
Anyway, one other person of off note claimed it might be an interstellar spacecraft
4:46
below that's right, and you know, looked, look and drew for in
4:51
support of that, the fact that it was behaving not like an asteroid.
4:56
Asteroids are solid lumps of rock or something that don't they don't out gas,
5:00
No gas comes from them, so they behave entirely under gravitational rules. You
5:06
know that the Newtonian gravity Neutonian physics actually predicts where they're going to go and
5:13
where they've been, and that's no problem. But this wasn't behaving like this.
5:17
And the suggestion was that something was outgassing, giving a kind of jet
5:20
thrust, and which is what comets. Do comets behave like that when they
5:27
out? Yes, the other song asteroids don't. So what was it?
5:30
Is it something in between these? We'd just love to see our cloaks and
5:34
get a spectrometer on it. And so again, within a few weeks of
5:38
that first apparition, a plan was put in place, an orbital plan that
5:43
would allow us to chase it. Reason why it's in the news again is
5:47
that that orbital plan has been tightened up and has now been demonstrated to be
5:54
feasible with existing technology. And I think it involves SpaceX's star Ship. So
6:00
you know, you get the biggest, best rocket you can and you go
6:04
through a succession of really clever gravity assists which are kind of counter intuitive.
6:14
And I should just say that it's it is a project that has long been
6:18
called Project Lyra, and it's actually one of the proponents of Project Lyra who
6:26
has put a blogout this week. This is why it's in the news to
6:30
say that you could do it with the SpaceX Falcon Heavy and NASA's Space Launch
6:35
System, both of them would be accept would be acceptable to send a probe
6:44
towards Jupiter. And then what you do is you do a very very clever
6:49
gravity assist at Jupiter in which you strip all the orbital velocity off your probe
6:56
so it falls directly back towards the Sun. Then this you know, you're
7:00
going the wrong way here. You think, what's what's happening. It's going
7:03
the wrong way, mums out there. But it turns out Jupiter's in the
7:08
right place, and calculations show that it is. You drop the spacecraft back
7:13
to the Sun and do something called an obese maneuver, which means bringing it
7:17
very very close to the Sun so that it gets a huge gravity assist,
7:23
and that propels it out towards Umua Mua at a velocity of about fifty seven
7:28
kilometers per second, which is enough to catch it up in ah twenty to
7:34
fifty seven. It win twenty fifty seven, that's when it catches up.
7:41
Yeah, ah, that's a disappointing, Well it is, but at least
7:47
it catches up. You know, we as you said, we all thought,
7:50
oh, yeah, it's long gone. This is hopeless, nothing's going
7:54
to happen here. But Project Lyra seems to have wings or legs or whatever
8:00
the term is, or exhaust plumes in the space world. So yeah,
8:05
possibly possibly worth thinking about. I should say this is written up in a
8:13
lovely article which is on an Australian science website that we don't often mention,
8:16
but they're very very good. I've written for them a long long time ago.
8:20
It's called Cosmos. Cosmos has an article called we have a plan to
8:26
chase down our first known interstellar visitor and it quotes somebody who's a old friend.
8:31
So I said, professor Alice Gorman, who's at Flinda's University, and
8:35
she's a space archaeologist. That's a job. She's a really interesting character to
8:41
talk to. So any word on where when this project might be launched if
8:50
they go ahead with it. So presumably you have a fairly tight window.
8:56
And I did see the day, but I've forgot what it was. I
9:01
think it's towards the end of this decade that you've got to do it.
9:05
So you kind of got to wait for for Jupiter to be in the right
9:11
place. I think I found it's Dune the seventh, twenty thirty. There
9:18
you go, end of the decade. Yeah, that's what I thought.
9:20
So you launch it on June the seventh, twenty thirty. It's going to
9:22
take you that long to raise the money to do this, and then by
9:28
twenty fifty seven you have a rendezvous with Mua and we get to see what
9:33
it was like old. Will you be in fifty seven. I don't want
9:39
to think about it. It'll be a big number. It'll be a bit
9:43
a number. Yeah, Okay, let's say I'll only be one hundred and
9:48
thirteen, so it's not that well, I'll be pushing one hundred in that
9:56
case. Let's assume we catch what do you think we will discover? What
10:01
do you think we might learn? We might as well speculate, because we're
10:05
not going to be round to find it. I think we'll find. I
10:09
think you'll find. I think it will turn out to be something similar to
10:16
what we used to call ultimate Toule, that object that new horizons flew past
10:22
after a Pluto ara coth. I think is it's accepted name today. I
10:28
think it's Arakov, which, if you remember, was two pancakes stuck together.
10:35
Yes, so that we thought it looked like a snowman, but it's
10:37
only a snowman if you look at it from one direction. It's quite thin
10:41
if you look at it from the other direction. And I think it'll look
10:43
like that, maybe just one of those pancakes. Okay. Will it give
10:50
us any indications of whether or not things are different beyond our solar system or
10:54
are we expecting that there'll be a standard model? No? I think it
11:00
will. Yes, it will reveal the nuances of what makes solar systems individuals,
11:07
if I put it that way, because they you know, I don't
11:11
know whether there will be any thoughts of going into orbit around it. That
11:16
would be fantastic if you could do that, But I suspect that the closing
11:20
velocity, like in the case of New Horizons, it was going too fast
11:24
to ever think about slowing it down to go into orbit around Pluto. In
11:28
fact, I think it passed it at I remember rightly, something like thirteen
11:31
or fourteen kilometers per second. It was a very high speed flyby. But
11:35
in that time, if you're careful with your preparation, as the New Horizons
11:39
team definitely were, because they absolutely read the harvest of data from Pluto.
11:46
If you're careful like that, you can gain a huge amount of information.
11:50
Spectroscopically. You could have you know, all the mass spectrometers and things on
11:56
your spacecraft that would sample the environment of umuma because if it's been out gassing,
12:01
it's probably got kind of atoms around it and things like that that you
12:05
know that that that sub atomic particles that that give some insights into what it's
12:11
made of in detail. So yeah, it would be worth doing. Yeah,
12:16
what about what about the other one? Because this this isn't the only
12:18
exo asteroid that we've discovered. Was the boris of Yeah, that was definitely
12:24
a comm Why not chase a comment? Was it? Yeah? So that
12:28
was that was a kind of standard comic that behaved very much in the way
12:31
that comics behave in our solar system. There were I think some slight differences,
12:37
but but it we're remembering stuff from our coverage back then. But yeah,
12:43
it's it's a it's that was a comic, and that was definitely a
12:46
comic to behaved just like comments do. Okay, so it so it was
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just one from within our solar system comic. We've got an exo comet and
12:58
an exoestra, so the asteroids are more interest because it behaves. It's got
13:03
certain aspects of its behavior which are more comet like than asteroid like. But
13:07
everything about it said it was an asteroid. Yeah, except for the fact
13:13
that it's something's accelerating. It's and that's of course why Havil blackt on the
13:18
on the intelligent life bandwagon, because maybe someone was controlling it. Well,
13:24
you know, it could be something from an intelligent civilization. It's probably them
13:28
getting rid of all the plastics that were destroying their planet. Could be that.
13:35
Do plastics go a ready if you put them in space for a million
13:37
years? Probably? Yeah, maybe maybe, Well I hope they do get
13:43
this particular mission off the ground. When you're talking about the speeds where so
13:48
the mission will travel after its slingshot almost double the speed of Mo and Moor.
13:54
Is that what we're thinking. I think it's something. Yes, that's
13:56
right. Yeah, they've heard along, aren't they. There's an incredible space.
14:03
To get to those speeds, you need this curious maneuver that sends you
14:07
past the Sun. And one of the things that this article, one of
14:09
the points it makes, is that that's actually its distance from the Sun when
14:15
that maneuver takes place, is less than the Parker Solar Probe, a big
14:20
part more than the Parka Solar Probe has experienced. So the Parka Solar Probe
14:24
which is shielded to protect it from the Sun's radiation, has already survived being
14:31
less than that distance from the Sun, so that's solved as well. It
14:37
is a good sign. It's all right, well we'll watch with interest.
14:39
We've got a few us up as slaves. They've got they've got six years
14:43
to get this all funded and get the hardware ready, so yeah, it
14:50
could well happen. Six years. I guess there's not really a long time
14:52
in planning a space mission, but yeah, they haven't got they haven't got
14:56
any more time than that. So yeah, let's hope it's a success in
15:03
the planning. And if you want to read about that, you can go
15:05
to cosmosmagazine dot com. This is Space Nuts with Andrew Dunkley and Professor i've
15:11
Fred Watson. Let's take a break from the show now to tell you about
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deal. Now back to the show three space Nuts. Okay, Fred,
18:00
let's turn our attention to planet formation. And you and I have talked about
18:04
how planets basically form from you know, discs of debris that sort of come
18:12
together, the accretion all that sort of stuff, and then they sort of
18:18
globe together under their own gravity and become a mass. And we always just
18:22
assumed, I suppose that it turns into a sphere by default. But now
18:27
they're starting to thinkang on, we're missing a piece of this puzzle. It's
18:32
not quite like that. And the early, the early planets, the infant
18:37
planets, if you like, are not spherical at all. Indeed, that's
18:44
right, possibly possibly, possibly, yes, always got to say that when
18:49
we're talking saying space science theory. Possibly, and it's because there are there
18:56
are actually, you know, we kind of in in our simplistic way here
19:02
at space Nuts, we do simplify some of the details, and there are
19:07
minds. That's for my personal benefit. Of course, it's mine as well,
19:14
because a lot of these are fields of astronomy that I'm not an expert
19:18
in. I've worked in many fields of astronomy, but not everything, but
19:21
I do have a you know, fairly good overview of what's going on.
19:25
But so there are basically two theories, are two possible methods by which we
19:33
think planets are formed. One is called core accretion. So course ore e
19:41
accretion is stuff coming together. And I'm actually quoting here from one of the
19:47
authors of the paper that we're going to talk about in a minute. Is
19:52
his name is Adam Fenton. Let me in fact, i'll read what he
19:56
said, because that's the easiest way to do it. Many ends of planets
20:00
switch planets that orbit stars in other solar systems outside of our own have been
20:03
discovered in the last three decades, but more than five thousand now. Despite
20:07
observing many thousands of them. How they form remains unexplained. It is believed
20:12
that they either form through core accretion, which is a gradual growth of dust
20:17
particles that stick together to form progressively larger and larger objects on long time scales,
20:23
or directly by the breaking up of large rotating protostellar discs around young stars
20:30
in short time scales, which is what we call the theory of disk instability.
20:36
Now I've kind of read about both of these, but I know I
20:40
was interested to hear that there's still two competing theories. So Adam goes on
20:47
to say the theory, this theory is appealing due to the fact that large
20:51
planets can form very quickly at large distances from their host star, explaining some
20:56
exoplanet observations. And so what they've done is they've run models of this second
21:03
model, this disk instability model. So just to recap, what you've got
21:07
is a rotating disc of debris, dust and gas around a new star.
21:15
And we know they exist because we can see them. We've got many images
21:18
from the Alma spacecraft, sorry, the Alma telescope in particular up there in
21:22
the northern and the northern Atacama Desert in Chile, the Atta Karma Large millimeter
21:30
array, so we know these things exist. And so just recapping the disk
21:36
instability method, you've got a disc of stuff in which you get swirls,
21:41
and those swirls are what then form the planets rather than you know, just
21:45
just being like an empty space with bits of dust coming to stick together gradually
21:52
building up planet isimals and proto planets, I mean planet planet simals and protoplanets
21:57
might be involved in the disc instability model, but the main point about it,
22:03
as Adam says, is it's very much quicker. You know, you're
22:06
talking about a few million years rather than hundreds of millions of years. And
22:11
what they've done so this science has been done from actually the University of Central
22:18
Lancashire's Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy. I used to work
22:23
very closely with those people in the University of Central Lancashire should get in touch
22:29
with them again and see how they're doing, because this is great work.
22:32
But what they've done is they've done simulations. If you've got, you know,
22:37
want to work out a theory as to what's happening, they've done some
22:41
simulations of this disc instability way of forming planets. They've run actually half a
22:48
million hours of central processing unit time on a high performance computer computing facility in
22:59
the uk UH and they've produced some very very spectacular imagery of what protoplanetary disc
23:07
forming planets might look like. And what it does is it generates models of
23:12
planets which turn out to be oblate spheroids. Watch an oblate spheroid. It's
23:18
an M and M. It's something very flattered. So or as smarty depends
23:26
on what donate the red ones? Why don't you eat the red one?
23:30
They band the red Smarties. Apparently they had a food coloring in them that
23:36
was considered to be carcinogenic. True, look it up, I will,
23:42
I will look it up. Yeah, so yes, so well, I
23:48
mentioned Eminem's for our transatlantic sorry transpecific listeners. But yes, smart is what's
23:55
the same, aren't they really? I used to devour those things by the
23:59
thousands as a kid could explain a lot new Smartest have played a part in
24:06
my history too, Andrew, because the very first telescope I ever made used
24:12
the smartest tube to start with, and with a lens of either wind,
24:18
so it wasn't a very big one, but it worked. It actually worked.
24:22
Wow, it's about nine at the time, I think finished the smartest
24:26
and made the tube. Terrible dead joke. Aren't you as smartie? Maybe
24:34
not now, but perhaps I was there anyway. Yeah, so, but
24:38
interesting stuff. So that's a surprise because people have thought, you know,
24:44
we we would just generate spherical planets, and eventually when we start getting huge
24:53
telescopes like the ELT and we can actually look at these protoplanets directly, we
25:00
might need to know what shape they are. And in fact, to some
25:03
extent that's true even now with observation some of the observations that are made,
25:08
for example by the James web Space telescope. It would be very helpful to
25:12
know if the inference that you're making that there is a planet in orbits around
25:17
this star is smart shaped rather than rather than spherical, because it would actually
25:22
change the modeling of you know the way the light reflects off the surface of
25:26
the planet. So it's important work and very nice to see it coming out
25:30
of the University of Central Lancashire. Are they suggesting, though, that this
25:36
could apply to all planet formation or is this a circumstantial thing? It depends,
25:44
you know, what turns out to be the most important method or the
25:48
most How can I put it? Basically? What method has given rise to
25:57
most planets. That's by method, I mean either core accretion or disk instability.
26:03
These two different models of our planets form. Eventually we're going to be
26:07
able to distinguish between the two. Are going to be parameters that might be
26:12
measurable that would distinguished between them, And in fact, the flattening or a
26:17
blatness of a planet, how squashed it is, might be one of them.
26:21
And by that I mean a young planet, because it's likely that the
26:25
what's called the differentiation process, which is actually what makes planets spherical, that
26:30
might take over as the planet, you know, becomes a big enough for
26:34
gravity to pull it into a spherical shape. So it's speculated, I mean,
26:41
I'm speculating here, but I think the inference is that these newly born
26:44
planets are flattened, rather than all planets being flattened, so that it's only
26:51
a short period in its early history that a planet will actually be rather like
26:57
a smarty rather than a rather than well, a different sort of chocolate,
27:03
a malteeser, let's put it. Yeah, a maltisa, a jaffer or
27:10
a Jaffeka. Are the Jaffers? Yeah, Jeffers, that's right, not
27:12
Jeffers. Yes, yes, that's that's another. That's another one of my
27:15
childhood sweets that a lot of people didn't eat because they became projectiles at cinemas.
27:22
It was a thin yes, throwing throwing jaffers at the screen because they
27:26
made a beautiful crack when they hit it. Oh dear, Oh we were
27:30
so naughty back then. Yep, yeah, I never did it. Of
27:36
course, of course you wouldn't have done you you would have been perfectly well
27:40
behead. Yeah. Yeah, well you know, I've never been kicked out
27:44
of a cinema. So it says two things. I was good or I
27:47
never got caught. Yes, I think that's right. It might be the
27:51
latter there, but that's I think an speculation of Mike, do they do
27:56
they know how our planet was formed? Has that been sorted out or is
28:02
it possible what we were once a smarty Yeah, I think so, because
28:07
I don't think it's ruled out that the Solar system, that the Solar System
28:12
formed by instability, and you know, we may find that that that phenomenon,
28:22
that of planet formation, might turn out to be the one that was
28:26
dominant, in which case, maybe yes, the Earth was flatten. I
28:27
mean, the Earth is slightly flattened to this day. I can't remember the
28:33
exact dimensions, but the distance from Paul to pol Is is smaller than the
28:37
distance across the equator. So it's it's an oblates. Pheroid is the technical
28:45
term for what its shape is, and the most pronounced one in the Solar
28:48
system is it Saturn, which is quite obviously not circular when you see it's
28:55
when you see an image of it, it's obviously intent. Okay, but
29:00
that's not because of formation. That's what it's like now. Yeah, that's
29:03
right, that's what it's like now. But maybe it never never really,
29:07
you know, because of its spin. It rotates very quickly, is ten
29:11
hours or thereabout, and it's a big object. That's the mechanism by which
29:17
it is remaining flat. But if it was formed by a disk instability.
29:21
Maybe it started off even more flattened as maybe the Earth did too, and
29:25
gradually got spherical as the differentiation process took place. Well, I mean,
29:30
you could argue that the Earth isn't spherical because of its rotation. It's wider
29:37
than it is high, isn't it. Yes, Yes, I just saying
29:41
the distance between the holes is less than the distance across the equator, maybe
29:45
by forty three kilometers. Actually, I just looked it up, which is
29:52
not much in the scheme of things when you think about it. Oh,
29:55
that's right, twelve and a half thousand kilometers across that. The most remarkable
30:00
object in the Solar system in that regard is actually the Sun, which is
30:06
flattened. You know, it's one point three million million kilometers in diameter,
30:11
is flattening at the poles is only ten kilometers, which means it is almost
30:17
perfectly spherical. It's a very very very spherical object. Yeah, was perfectly,
30:26
which is given its size, is quite incredible. But maybe that's a
30:29
factor. Maybe the size and the gravity involved is is what keeps it that
30:33
way. Yeah, And it's slower rotation twenty seven days to rotate once.
30:38
Yeah, indeed all right, fascinating story about flat planet formation which you can
30:45
read on fizz dot org. That's p h y s not if I double
30:49
z it. A few people have been caught out by that. This is
30:52
Space Nuts Andrew Dunkley with Fred Watson Space Nuts. You to the Space Nuts
30:59
put available at Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player.
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You can also stream on demand at bytes dot com. This has been
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another quality podcast production from nights dot com production. Note wondering where the Q
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and A segment is never fear It now has its own podcast called funnily enough
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No need to do anything. It will turn up just like Space Nuts does
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