In this episode, you will be able to:
· Understand the origins of water in the solar system and its significance for life beyond Earth.
· Explore the fascinating process of the formation of the solar system and how it shaped our cosmic neighborhood.
· Discover the potential for terraforming Venus, unlocking the possibility of transforming inhospitable planets into habitable ones.
· Uncover the abundance of water in the solar system and its implications for future space exploration and colonization.
· Learn about the slingshot effect in space missions and how it enables spacecraft to travel vast distances with limited fuel.
'Two out of the three atoms in a water molecule are hydrogen. So two thirds of your 75%, which is 50% of the atoms in your body, come from the Big Bang. Why? You feel old these days? 13.8 billion year old hydrogen.' - Andrew Dunkley
Terraforming Venus Possibilities: Terraforming Venus is a topic of fascinating discussion. The suggestion of transforming its carbon dioxide-heavy atmosphere using photosynthetic algae could potentially cool it down over extended periods. However, the surface atmospheric pressure on Venus is significantly higher than Earth's, making such an endeavor incredibly complex and presently unfeasible.
The key moments in this episode are:
00:00:00 - Introduction to Dark Energy Survey
00:08:15 - Peregrine Lander Mission
00:13:48 - Dark Energy Survey Results
00:16:18 - Quintessence and Thunderplump
00:17:38 - Exploring the Cosmic Megastructure
00:19:56 - Universe Homogeneity and Big Ring Discovery
00:23:16 - Speculation on Megastructure Origins
00:24:53 - Unraveling the Mystery of Cosmic Structures
00:29:32 - Addressing Audience Feedback
00:34:17 - Formation of the Solar System and Origin of Water
00:37:27 - Slingshot Effect and Spacecraft Momentum
00:40:43 - Terraforming Venus and Atmospheric Cleanup
00:45:04 - Are Humans Stars? Stardust Origins
The resources mentioned in this episode are:
· Visit spacenutspodcast.com or spacenuts.io to send in your text or audio questions.
· Listen to Space Nuts on Apple Podcasts, Spotify, iHeartRadio, or your favorite podcast player.
· Stream on demand at bitesz.com or spacenuts.io.
· Check out the documentary The Stars by the BBC.
· Send feedback or questions through the Space Nuts website.
Become a supporter of this podcast: https://www.spreaker.com/podcast/space-nuts-astronomy-insights-cosmic-discoveries--2631155/support.
00:00:00
Hi there. Thanks for joining us on this episode of Space Nuts.
00:00:04
My name is Andrew Dunkley, your host and coming up, we're going
00:00:07
to be looking at a Dark Energy Survey that's got people
00:00:11
questioning, well, of all things, the Cosmological
00:00:14
constant. We'll also be looking at a mega structure that's been
00:00:18
discovered.
00:00:19
And when we say mega structure, this is not a human made thing.
00:00:22
This has been made by the universe itself. The, the
00:00:26
trouble is, it is so big, they're now wondering how it's
00:00:30
possible that it exists. I mean, it exists.
00:00:33
It does, but, people are scratching their heads and,
00:00:37
we'll do a bit of a Peregrine update, which is not a very good
00:00:40
update at all. And plenty of questions. We've got a whole
00:00:43
bunch to get through this morning. So, this morning today
00:00:47
tonight, this evening, this afternoon, whatever time it
00:00:50
might be where you are all coming up on this edition of
00:00:54
Space Nuts.
00:00:58
10, 9 Space Nuts 5432.
00:01:12
And joining us to unravel all those mysteries and much, much
00:01:15
more is Professor Fred Watts, an astronomer at large. Hello,
00:01:18
Fred. Hi, Andrew How is he going? I am. Well, do you like
00:01:22
my shirt? This was sent to us by Marie Claire Mercer who went to
00:01:28
the dart mission at NASA and she promised to send us some bits
00:01:33
and Bobs. And I'd just like to say thanks for my amazing
00:01:37
t-shirt. Judy says my color is blue.
00:01:40
So there it is and, and the, the dart sticker and the Planetary
00:01:45
Defense Co Ordination office sticker. And she even threw in
00:01:49
one of these artemis sticker. And I'm guessing I am now a
00:01:55
member of the planetary defense group because I got a planetary
00:02:00
defense badge as well. So, thanks Marie Claire. That's so
00:02:04
generous of you really appreciate it. That's, that's,
00:02:07
that's great gear, what's happening in your world, Fred.
00:02:12
Well, it's it's been a nice busy weekend. We were in New Zealand
00:02:16
doing talks at the central star party in the North Island. You
00:02:21
just reminded me though with that planetary planetary defense
00:02:26
button that you held up for those who could see it.
00:02:30
Well, this time last year when I was at the Un in Vienna,
00:02:33
principally there to be part of Australia's delegation talking
00:02:37
about dark and quiet skies, the, the issue of you know, the, the
00:02:43
pollution by satellite constellations in particular. I
00:02:47
also attended a meeting of the the planetary defense body, the,
00:02:52
the, the branch of co Kuo, the Committee On The Peaceful Uses
00:02:56
Of Outer Space that looks after planetary defense.
00:02:59
So I had a, I had a couple of hours with them, which was
00:03:02
really fascinating stuff. And in fact, what they were doing at
00:03:06
that time was because there was a big planetary defense meeting
00:03:10
coming up. This would have been last year in Vienna.
00:03:13
And they were essentially setting up a scenario which was
00:03:19
gonna play out in real time during the meeting that they
00:03:23
were planning, which was about what you do if there is an
00:03:28
asteroid with a high chance of impacting the Earth. And one
00:03:31
that is you know, significant enough to, to warrant global
00:03:36
action. And that this scenario was being set up with incredible
00:03:43
detail.
00:03:44
For example, so I think it was a one kilometer or thereabouts,
00:03:48
maybe 5500 m asteroid that they were postulating. Now, our
00:03:53
detection systems are currently such that finding something like
00:03:56
that should be easy. But so they had to work out a way where it
00:04:00
would sneak through our planetary defenses. Indeed, they
00:04:03
did, they had an orbit for it that would have brought it in
00:04:06
more or less from the direction of the Sun.
00:04:08
And so this was all laid out in great detail. I don't know how
00:04:13
it went in the end because I wasn't part of that meeting.
00:04:15
But, I imagine the, you know, the, the, the urgency which
00:04:20
would accompany something like that going, running along
00:04:24
through a, through a scientific me. It's quite, quite amazing
00:04:27
stuff.
00:04:28
Yeah, that'd be a really great exercise to witness. I reckon,
00:04:33
be fascinating to, to look at how they worked out what to do
00:04:37
about it if anything. But, yeah, that's what this is about
00:04:41
though. The double, asteroid redirection test. Yes, it is.
00:04:45
Was done, year before last now, wasn't it?
00:04:49
And, yeah, they're trying to find ways of deflecting these
00:04:53
things. Should we ever have one that threatens the planet? Fred,
00:04:58
let's get on to topic one which will rush over pretty quickly
00:05:02
because, it's a fete de compli now, the Peregrine Lander that
00:05:06
was being sent to the moon, which was, unfortunately
00:05:09
leaking, propulsion fluid or fuel, whatever you want to call
00:05:13
it.
00:05:14
Mission appears doomed. Well, now they've, they've been
00:05:17
keeping an eye on it. They've been keeping us informed. They
00:05:20
were hoping there might be a way of, of, resurrecting some of the
00:05:25
mission targets. But, it appears, should I say all is
00:05:31
lost?
00:05:32
Y yes, that's right. So, now the information I have on this is a
00:05:36
few days old. It's about three days old, Andrew. But, the
00:05:41
company that operates the Peregrine Lander Astro Botic,
00:05:45
were releasing news that they expect that it would actually on
00:05:51
its orbit would bring it back so that it would re enter the Earth
00:05:54
's atmosphere and most likely would burn up in the Earth's
00:05:58
atmosphere.
00:05:59
And so, what they've been doing is, you know, using what time
00:06:04
they've got to do as many scientific experiments as, as
00:06:07
are possible. Because there were, I think there was at least
00:06:10
one of the NASA payloads that was on the Peregrine spacecraft
00:06:14
that actually I can't remember which one it was, but could be
00:06:16
used to make useful measurements in transit rather than waiting
00:06:21
for a landing on the moon.
00:06:22
So they the landing on the moon, be it soft or hard by hard
00:06:28
landing, we mean a crash is now off the agenda as far as I
00:06:33
understand. And it looks as though, yes, the the spacecraft
00:06:37
will in fact collide with Earth. And if I might just just mention
00:06:43
one of our listeners didn't exactly take us to task but did
00:06:48
mention something that I didn't have time to talk about last
00:06:51
week when we were discussing this.
00:06:53
And that is that the launch vehicle f for that took
00:06:58
Peregrine into orbit, also carried another another
00:07:03
experiment, another spacecraft or, or another experiment on
00:07:07
board which contained once again, human remains of which
00:07:11
there were rather a large number. These are essentially
00:07:14
people's ashes, many of whom were connected with star Trek.
00:07:19
And that, that was quite a succe an absolutely successful launch.
00:07:24
It, that capsule has gone into a heliocentric orbit, which means
00:07:28
it will be for all time orbiting our planet, our Sun along in a
00:07:33
similar orbit to of the Earth. So, one of our listeners
00:07:38
actually commented that her husband's ashes were on that
00:07:42
space flight. So that's a lovely touch to add to our coverage
00:07:47
with that.
00:07:48
Yeah, it gives us kind of a direct connection to it in, in
00:07:51
one way, I suppose. And yeah, I'm, I'm glad they they came
00:07:55
forward and told us about it because it's certainly got a lot
00:07:57
of chatter on our social media platform. So thanks for letting
00:08:02
us know.
00:08:02
And yeah, it must have been quite an emotional thing to be
00:08:07
involved in too. So, Peregrine, unfortunately, yeah, all is lost
00:08:13
there by the sound of it. Let's look at this next story. Fred a
00:08:19
about this Dark Energy Survey and you, you always hope with
00:08:23
the survey that you come up with answers. We've come up with huge
00:08:27
questions.
00:08:29
Yeah, that's right. So the, the Dark Energy Survey is an
00:08:35
international collaboration which I think has been running
00:08:39
for best part of a decade UU using large telescopes. It which
00:08:47
have been used to make measurements of well supernovae
00:08:51
explosions and things of that sort.
00:08:54
In fact, one of my close colleagues is a member of the
00:08:58
Dark Energy Survey and unfortunately, he's on holiday
00:09:00
at the moment till the end of the month. So I can't, I can't
00:09:03
ask him about this. But the 243rd meeting of the American
00:09:10
Astronomical Society in New Orleans this month.
00:09:15
The, that's the American Astronomical Society Al always
00:09:18
has its meetings right at the beginning of the year, which is
00:09:20
great. Cos you get lots of good news stories coming out of it
00:09:23
and this is one of them. So, the, the, the the, some of the
00:09:28
results were presented of the Dark Energy Survey were
00:09:31
presented at that meeting.
00:09:33
So, what's Dark Energy we know from measurements starting back
00:09:38
in 1998 that the expansion of the universe is not slowing
00:09:45
down, which is what was widely believed before that, that the
00:09:48
expansion is actually accelerating.
00:09:50
And that gave rise to a Nobel Prize, I think in 2011, three
00:09:55
Nobel Prize winners shared the prize for their contribution to
00:10:00
that discovery that that the universe is expanding ever more
00:10:05
rapidly. And that's attributed to something we call Dark
00:10:08
Energy, which is an Energy possessed by space itself.
00:10:13
It's a thing that's common through to the old universe, I
00:10:15
like dark matter, which is actually a substance, one albeit
00:10:20
that's invisible. But it, it likes to be where gall normal
00:10:24
matter is because we think the two tend to go together whereas
00:10:27
Dark Energy is everywhere. It's a, it's a property of the
00:10:29
universe as a whole.
00:10:31
And now, the early days of Dark Energy studies were sort of
00:10:40
perhaps taken or commenced with a very broad minded attitude as
00:10:45
to what this thing might be. And there were a few suggestions,
00:10:50
one of them I remember was Quintessence 1/5 fundamental
00:10:54
force of nature with a lovely name. Quintessence.
00:10:57
It goes back actually, I think to ancient Greek philosophy,
00:11:01
Quintessence would have been something that would actually
00:11:05
basically evolve with time. Whereas as time went on, it
00:11:11
looked as though an alternative explanation was more likely to
00:11:15
be correct.
00:11:16
And that is that Dark Energy behaved in a way that was
00:11:20
consistent with something that Einstein introduced back in the
00:11:24
thirties. Back, I beg your pardon back in the twenties,
00:11:27
something called the Cosmological constant, which was
00:11:29
a a fudge he made to his equations of relativity to make
00:11:33
the universe not expand because at the time he did this, he
00:11:36
didn't know the universe was expanding.
00:11:39
And in fact, he called it his greatest blunder. The fact that
00:11:42
he, he put this Cosmological constant into the equations
00:11:45
before, not long before it was discovered that actually, it
00:11:48
wasn't needed because the universe was expanding.
00:11:51
But the fact that the universe is expanding ever more rapidly,
00:11:55
suggests that there is actually a Cosmological constant. And
00:11:59
that was the other theory that is, I, I guess, I, I, become
00:12:05
more widely held as being the reality. So what's the
00:12:10
Cosmological constant? What, why is it different Quin from
00:12:13
Quintessence?
00:12:14
The, the the bottom line is that it doesn't evolve over time. It
00:12:18
is something that is a property of space itself that is
00:12:23
constant. Hence the name. But that means that as space gets
00:12:28
bigger, the amount of Energy that the Cosmological constant
00:12:32
puts in increases.
00:12:34
So space gets bigger and the Energy increases as well in a
00:12:38
sort of linear fashion because it's, it's a constant. Now, to
00:12:43
cut a long story short, the results of the Dark Energy
00:12:47
Survey actually suggest that that is not quite the case.
00:12:55
There is basically a property which we call the equation of
00:12:59
state.
00:13:00
And the, the there's a number you can attach to that if Dark
00:13:04
Energy is the Cosmological constant, then the equation of
00:13:09
state is exactly minus one.
00:13:12
But it's starting to look as though that is not the case. And
00:13:19
the answer looks like it might be something like minus 0.8
00:13:28
rather than minus one minus 0.8 is the best figure they've got
00:13:35
for it and that then suggests that it's not the Cosmological
00:13:40
constant that, there's something that actually does evolve with
00:13:44
time as the universe.
00:13:46
I, ages, I don't know whether that's a clear expla explanation
00:13:51
or not, Andrew, but it's the best I could do.
00:13:55
Well, well, it's certainly an explanation but it's, it's very
00:13:58
confusing. So what they're suggesting is up until now, we
00:14:03
thought this, we've done this survey. Now, we don't think this
00:14:07
anymore maybe. Is that the best way to describe it?
00:14:11
Yeah. With a, with a, a level of uncertainty that actually kind
00:14:16
of eliminate, it doesn't, I suppose it, it, it tends to
00:14:19
eliminate the idea that it's minus one. I think they've got
00:14:24
plus or minus 0.18 on the error bars and that means that there
00:14:32
is still a chance of it being minus one a at the level of one
00:14:38
in 20.
00:14:39
So it's a 5% chance. But well, you know, the bottom line and it
00:14:47
comes from a comment by one of the scientists involved with
00:14:52
this survey. The bottom line is as usual, scientists want more
00:14:56
data. And so it looks as though there is more research needed.
00:15:03
Some of which will undoubtedly be done by the new Vera C Ruben
00:15:09
Observatory in Chile, an 8.4 m telescope that will survey the
00:15:15
universe, I think every three days of the whole sky to give us
00:15:20
a picture of, of what, what, what we call transient events
00:15:24
and supernova explosions, which is what you base these, these
00:15:28
these measurements on our transient events. So there's
00:15:31
more to come, there is more to come.
00:15:33
I'm glad to hear that because if we stop there, we'd just be, you
00:15:38
know, forever scratching our heads and confused. I, I, I've
00:15:42
heard the term qui quintessence before. You know, I, ok, I
00:15:47
watched the movie, the, the, the Secret Life of Walter Mitty, not
00:15:51
the original one, but the remake from a few years ago now. Great
00:15:56
film, but they, they do actually use the word quintessence in the
00:16:00
dialogue of that film to describe a photograph.
00:16:05
Well, there you go. There you go. It's a great word. It's a,
00:16:09
it's a, it's a nice word. That's right.
00:16:13
So maybe it'll come back into vogue for Dark Energy. If maybe
00:16:17
the Cosmological constant, maybe quintessence is what it is.
00:16:20
I read the other day in the United States that every year
00:16:25
runs a list of words they want to revive from Old English. And
00:16:29
the one I like that they want to bring back this year is, you
00:16:33
know, it, it describes heavy rain from a, a thunderstorm. It
00:16:36
's called thunder plump.
00:16:39
I reckon they should bring that back.
00:16:42
That's a great word.
00:16:44
We get that. We're we're supposed to get that this
00:16:47
afternoon actually here in Sydney. So I'll tell people that
00:16:52
we're experiencing a thunder plump p that's the word.
00:16:56
Yeah, it is. Alright. We'll leave that there. But I'm sure
00:16:59
in future episodes of Space Nuts, we will be again looking
00:17:03
at Dark Energy and the Cosmological constant. This is
00:17:07
Space Nuts. Andrew Dunkley here with Professor Fred Watson.
00:17:13
Ok. All Space Nets. This next story is I suppose slightly
00:17:22
related to the one we just did, Fred. And, and this all sent us
00:17:25
around a mega structure. Now, we're not talking about a giant
00:17:29
space station here. We're talking about a giant series of,
00:17:34
I don't know what you'd call them. I I it's a, it's a, well,
00:17:38
they, they're calling it a cosmic mega structure. Do you
00:17:41
want to explain first up what that actually is?
00:17:45
Yeah, it's, it's a, it's a bunch of Galaxies basically.
00:17:49
So, so the, the structure of the universe, the three dimensional
00:17:52
structure of the universe, which is something that has been, you
00:17:55
know, a hot topic in Astrophysics and cosmology for
00:17:59
several decades.
00:18:00
And that actually, in fact how our telescope, the Anglo
00:18:02
Australian telescope was one of the pioneering facilities that
00:18:06
allowed us to map that with the two DF spectroscopy system,
00:18:12
something that measures the red shift of Galaxies 400 at a time
00:18:16
rather than one at a time, which is what it used to be.
00:18:19
So, the discovery that came from that sort of work and this was
00:18:22
in the early two thousands is it kind of confirms what was
00:18:27
previously thought there, there is a kind of honeycomb structure
00:18:31
within the universe that Galaxies form almost in sheets
00:18:37
and, and filaments along this what is called the cosmic web,
00:18:43
which is predicted by, you know, what we see, what we understand
00:18:48
the Big Bang to have been like that, you would get this web of
00:18:50
material because we think it, it actually the framework itself is
00:18:54
dark matter and the g the Galaxies cluster around this
00:18:57
dark matter to form a visible version of a dark matter web
00:19:02
because the Galaxies shine and dark matter, dark matter
00:19:04
doesn't.
00:19:05
Now. Typically the the, so if you think of, you know, the the
00:19:13
the universe as being like a foam, a foam of soap except that
00:19:19
the soap is replaced by Galaxies and it's all on a very large
00:19:22
scale. Typically, the voids within this foam of Galaxies
00:19:28
would be of order 100 million light years thereabouts.
00:19:32
That's the typical size of a, of a void in the cosmic web. And
00:19:37
so, that seems to be an inbuilt principle of the universe and it
00:19:43
reflects something that we, we call the cos the Cosmological
00:19:47
principle which is that the universe is effectively the same
00:19:53
in all directions.
00:19:55
You know that the universe is homogeneous. I mean, it's, it's
00:20:00
not clearly cos it's got this structure in it. But by and
00:20:02
large, you look in any direction and you see the same kind of
00:20:06
structure that's the basic Cosmological principle.
00:20:10
And, and actually, to be more precise in in what I've just
00:20:15
said, it states that above a certain spatial scale and it,
00:20:19
that's typically 100 million light years above a certain
00:20:24
spatial scale, the universe is homogeneous and looks identical
00:20:28
in every direction. And that, that's basically what we thought
00:20:32
to date.
00:20:33
However, along comes yes, another paper at the 243rd
00:20:38
meeting of the American Astronomical Society. I told you
00:20:41
though, a lot of interesting research comes out of those
00:20:44
meetings, Andrew. That, that says there is something that is
00:20:49
quite clearly a structure and it 's a mega structure, an
00:20:53
arrangement of Galaxies.
00:20:55
But it's much, much bigger. In fact, it's a ring with a
00:21:00
diameter of not 100 million light years, but 1.3 billion
00:21:05
light years. So you're talking about something, you know, more
00:21:09
than 10 times the scale of your, what, what you think is the
00:21:14
biggest thing in the universe.
00:21:17
It's being, guess what it's being called, Andrew. Oh And it
00:21:22
's big.
00:21:24
Not the big ring.
00:21:26
Yes, it's the big ring.
00:21:29
Here we go again.
00:21:31
Astronomers curiously that, that I should say it's actually in
00:21:37
the constellation of Bote which is a northern hemisphere
00:21:40
constellation.
00:21:42
But, and, and again, this is something that's emerged from
00:21:46
these large scale studies of the structure of the universe right
00:21:50
next to it and about the same distance away is an arc a, a
00:21:56
separate structure which is an arc of Galaxies.
00:22:01
And that's been called the giant arc, of course, I which, well to
00:22:08
the map, the map I'm looking at which is actually courtesy of
00:22:12
the Guardian. It's their article on this looks almost as though
00:22:17
these two structures are concentric. The big ring, 100
00:22:21
1.3 billion light years in diameter and sort of sharing a
00:22:25
similar center, a giant arc of Galaxies which is even further
00:22:30
away.
00:22:30
So you're looking at structures that are, that are much more
00:22:34
much more coherent if I can put it that way than what we've
00:22:37
expected to see. In fact, the, the giant arc is about 3.3
00:22:41
billion light years long. And so they, yeah, they're both bigger
00:22:47
than we expect.
00:22:49
And it suggests as the Guardian says that this raises the
00:22:55
possibility that these two structures are part of a
00:22:57
connected Cosmological system and it's bigger than anything
00:23:01
that we have expected to see so far. And I should just explain
00:23:07
sorry, sorry Andrew, just to explain where the da the, where
00:23:10
the data come from.
00:23:11
It's from a similar survey to what our two DF survey was on
00:23:15
the Anglo Australian telescope, but it's bigger, it's called the
00:23:18
Sloan Digital Sky Survey. And it 's a catalog actually, in this
00:23:22
case of distant quasars, quasars are, are just delinquent
00:23:25
Galaxies, but they're, they're brighter than normal Galaxies so
00:23:28
they can see them from billions of light years away.
00:23:31
As I was, going to suggest, th they think this, this ring that
00:23:37
we've just been talking about is actually more like a corkscrew
00:23:40
except we're just looking at it end on. So it looks like a ring
00:23:44
from Earth, but it's more of a corkscrew of Galaxies, isn't it?
00:23:49
Y yeah, that's, that's right. Exactly. That, that you've got,
00:23:53
you've got, because we're looking end on, it's like
00:23:57
looking at a spring, spiral spring end on. It looks like a
00:24:01
circle, but if you look at it sideways, it's, it's got a
00:24:04
helical structure.
00:24:06
And so, i it's, it's not really, I, I, you know, it's not like a
00:24:12
spring, it's probably like a very shallow spring, but a
00:24:14
spring that's aligned face on with the Earth with our own
00:24:19
planet or with our own galaxy. Let me if I may quote from the,
00:24:24
the Guardian article on this, which was actually written by
00:24:27
Hannah Devlin who's, one of their science correspondents
00:24:32
because this really puts the conundrum very, very nicely.
00:24:36
Cosmologists are unsure what mechanism could have given rise
00:24:40
to the structure. One possibility is a type of
00:24:44
acoustic wave in the early universe known as bionic
00:24:47
acoustic oscillations that could give rise to spherical shells in
00:24:51
the arrangement of Galaxies today.
00:24:53
Another explanation is the evidence of the existence of
00:24:57
cosmic strings, hypothetical defects in the fabric of the
00:25:02
universe that could cause matter to clump along large scale fault
00:25:06
lines.
00:25:08
Now this that, that's a really interesting suggestion because
00:25:11
cosmic strings have been discussed, you know, in the
00:25:16
theoretical world of astrophysics many times before.
00:25:20
But there's never been any evidence that they exist. They
00:25:23
are essentially as it says, they, they're zero dimensional.
00:25:27
They, they don't, they, they've only got one dimension, sorry,
00:25:29
put it that way. And that's the length which is why it's a
00:25:32
string rather than a ball or something. So it's got one
00:25:35
dimension and it is a defect in in space time and just going
00:25:41
back to the other possibility that was mentioned in this, that
00:25:45
little passage, a type of acoustic wave in the early
00:25:48
universe.
00:25:48
We do see evidence of those because the, the, the the
00:25:52
spottiness of the cosmic microwave background radiation,
00:25:56
that's the, the slightly hotter and colder regions, even though
00:25:59
they, it's only 01 of a of a degree, the difference that is
00:26:05
assumed to be caused by these acoustic waves.
00:26:08
In other words, the bang of the Big Bang acoustic waves in the
00:26:11
fireball that we could still look back and see over the, over
00:26:16
the distance of about 13.8 billion years. Look back telling
00:26:21
me if I put it that way.
00:26:23
Bottom line is though, you know, theory aside and you can only
00:26:28
have theory, but we really don't know why these things exist. Do
00:26:33
we don't know what the mechanism was or how it happened or
00:26:36
anything like that?
00:26:38
Yes, that's right. It, it underlines something that's the
00:26:42
importance of something that's always been very close to my
00:26:44
heart in the world of astronomy because that's what I used to do
00:26:46
when I was a practicing astronomer rather than a
00:26:48
bureaucrat. It, it underlines the importance of large scale
00:26:53
surveys, the idea of mapping the s the sky in very large scale.
00:26:58
As you see, if you, if you're only doing what we would have
00:27:01
called pencil being surveys where you look at a small area
00:27:04
of sky and, and probe the distance of Galaxies along that
00:27:07
line. It doesn't tell you anything about these large
00:27:10
structures. It's only when you actually look at huge swaths of
00:27:14
sky that you can detect things like the big ring.
00:27:17
And as as time goes on, maybe these surveys will progress more
00:27:23
widely. And you'll get the even bigger ring, who knows what we
00:27:27
might find as, as you know, as these data are analyzed. And
00:27:31
just one more footnote to this if I may, it was one reason why
00:27:36
back at the turn of the millennium, the United Kingdom
00:27:40
Schmidt telescope, which is a telescope very close to my
00:27:43
heart.
00:27:44
There used to be it's astronomer in charge at the Anglo
00:27:46
Australian. Oh, sorry, the Australian astronomical
00:27:48
observatory we did a survey which was the whole of the
00:27:52
southern sky of this kind and that was its strength. The fact
00:27:57
that with a wide angle of view in a in a telescope, the Schmidt
00:28:01
telescope had a six degree field of view.
00:28:03
You could do these surveys and probe large swathes of the
00:28:07
universe where it fell down. Was that a 1.2 m diameter telescope
00:28:13
can't look all that far into the universe. We could only look out
00:28:17
about half a billion light years whereas we're talking now about
00:28:21
several billion light years because it was done on a bigger
00:28:23
telescope with greater sensitivity.
00:28:27
Well, I all I can say is if there's a big ring that contains
00:28:32
billions and billions of stars, you're gonna have a big pharmacy
00:28:36
with a lot of big bottles of hemorrhoid cream nearby I reckon
00:28:39
because that's, that's too what they handle.
00:28:43
I, I will also go as far as doubling down on that terrible
00:28:46
joke. By saying, hang on a minute, you're gonna love this
00:28:49
one. You did say that this was found near the constellation of
00:28:54
BTE something I've been trying to avoid.
00:28:57
Oh dear.
00:29:03
Right.
00:29:03
So that we'll leave it there. But if you want to read that
00:29:07
story, it's it's on the Guardian.com website. A good
00:29:11
read. It's been yeah, a well written article, even though it
00:29:15
tells us this thing exists, we, we really do not at this stage
00:29:19
know why this is Space Nuts. Andrew Dunley here with
00:29:23
Professor Fred Watson.
00:29:28
321.
00:29:30
Space Nuts. Ok. Fred time to get to our Q and A section and this
00:29:36
is where we hand over to the audience who ask us questions
00:29:40
that sometimes we wish we could have always. But anyway, now
00:29:47
I've got one here. It's not so much a question. This comes from
00:29:50
something we were talking about last week. This is Emory.
00:29:52
Hello, Andrew and Professor Watson. This is Emery Stagner A
00:29:56
K A fax headroom calling in from Baltimore, Maryland in the
00:29:59
United States the work, but just listen to episode 386. And I got
00:30:03
unfortunately a correction for Mr Watson, the pressure on Titan
00:30:07
is actually only 1.5 bar.
00:30:11
That's actually pretty tolerable for humans. We could actually
00:30:14
walk around on the surface with just something to keep us warm
00:30:17
because the ambient temperature there is about 95. Kelvin, been
00:30:22
a listener for about two years. Great podcast. Listen every
00:30:24
week. Thanks a lot. Keep it up. Thanks.
00:30:27
Thanks. He, ok. Yeah. All right. You were thinking of Venus, I
00:30:30
think when we discussed that.
00:30:33
Yeah, I, I did, it's a long time since I've looked at the
00:30:36
figures. So it, I just, yes, pulled, pulled the first number
00:30:40
out of my head. I knew it was more than atmospheric pressure
00:30:42
on Earth. So thank you very much Emery and point taken. You're
00:30:46
absolutely right. I should have looked it up. Sometimes when we
00:30:49
get these questions and comments in, I'm very much working on the
00:30:54
long endeavor, the distant end of a memory.
00:30:57
Because yes, of course, I've written about things like that
00:31:00
and Titan such an astonishing world that you really are. Ii I
00:31:05
find myself captivated by just thinking of what it would be
00:31:08
like there. But a good point that we could walk around with
00:31:12
perhaps not quite normal clothing, but something to keep
00:31:15
us warm. But it doesn't have to be a pressure suit because the
00:31:17
pressure is more than we're used to on the outside.
00:31:20
Perfect. Well, yeah, just don't like the I, I don't like getting
00:31:24
cold.
00:31:28
Well, we're doing the Mea Culpas Andrew. I might just mention in
00:31:32
case he's listening in that we, we took note of some comments
00:31:36
from Jens in Sweden came in just before Christmas and, we'll,
00:31:41
we'll talk about those as well. Jens is also quite correct in
00:31:45
pointing out some flaws in things that I said on the spur
00:31:48
of the moment because, yes, I'm cast onto own devices.
00:31:52
When I'm answering these questions, they have no warning.
00:31:55
I don't know what's coming up and, usually it's, relying on my
00:31:59
memory, which is, as time goes on getting more and more faulty,
00:32:04
however, we'll keep going until people just switch off and don't
00:32:07
listen anymore.
00:32:09
Well, that's why we created Space Nuts in the first place to
00:32:12
keep you sharp. That was the only motivation for us.
00:32:17
Well, it's doing a good job. Thank you.
00:32:19
Ok. Let's move on to a question from Scott. Hey, this is.
00:32:24
Scott from Oregon. Just wanted to ask if we know how old the
00:32:29
water is that is on Earth? Was it existing before the Sun or
00:32:35
what? Thanks guys. Really enjoy the show.
00:32:38
Ok. How old is the water on Earth? Now, there's varying
00:32:44
theories as to where it came from.
00:32:47
Some theories are, you know, based on it being dumped here by
00:32:52
asteroids. Other theories are that it was already here when
00:32:55
the Earth started to form and it just leached out. It's probable
00:32:59
that both hold water.
00:33:02
So, does that mean that the water on Earth could vary in age
00:33:07
or do we take it back even further and say, well, it all
00:33:11
sort of happened at once. So the water is the same age
00:33:13
regardless.
00:33:14
That's a great answer. Andrew. Oh, you probably said, said,
00:33:19
said what I was gonna say?
00:33:21
You're right that, two main theories, one is that water has
00:33:26
arrived on Earth from comets and asteroids impacting in the early
00:33:32
history of the solar system.
00:33:33
And the other that the water was there all the time because the
00:33:38
molecular sorry, the cloud of gas and dust that the that the
00:33:43
Earth that the solar system condensed out of contained water
00:33:47
and some of that water found its way into the rocks and
00:33:50
eventually leached out as you've said.
00:33:53
Either way, I think the answer is right that, that it predates
00:33:58
the Earth.
00:34:00
So the probably the simplest scenario to visualize is the is
00:34:06
the impact scenario. So you start off with a cloud of gas
00:34:10
and dust which collapses under its own gravity. The middle part
00:34:14
of that becomes very hot and forms the Sun.
00:34:17
Meanwhile, a a rotating disc of material, dust, gas and other
00:34:22
rubbish swirls around the infant Sun and the planets basically by
00:34:30
a process of accretion which is stuff sticking together, they
00:34:33
grow in that disk.
00:34:35
But we that model tends to leave behind a sort of shell of the
00:34:42
original gas and dust in the cloud from which the, the Sun
00:34:46
formed much at a much greater distance than any of the
00:34:49
planets, way, way in the depths of the of space, beyond the, the
00:34:54
most remote planets and transunion objects and all the
00:34:57
rest of it. So we've got this shell of ice because it, it's
00:35:02
cold enough there that it, it, it just becomes ice.
00:35:05
It's, it's not vapor anymore. It 's, it's actually lumps of ice.
00:35:10
And those lumps of ice we call comets, they've got dust
00:35:12
embedded in them. And the thinking is that in the early
00:35:15
history of the solar system, when there were, there was
00:35:17
debris everywhere that some of those things impacted the baby
00:35:23
Earth and brought the water.
00:35:25
So what you're learning from that is that the H2O molecules
00:35:30
were probably in existence long, long before the solar system
00:35:36
came into being that they were present in the cloud of gas and
00:35:39
dust, which was within our own galaxy.
00:35:43
And that's that is, you know, is the, is the origin of the, of
00:35:49
the water and water being the most common two element molecule
00:35:53
in the universe. That's the key thing to this. It's everywhere.
00:35:57
Not just here, it's everywhere.
00:35:59
Yeah. And there was a time we didn't realize that we just
00:36:04
thought, well, we've got water here but we can't say it
00:36:06
anywhere else. So it can't exist.
00:36:08
Yes, but it does. And we actually know, there's more
00:36:12
water in the solar system than we've got on Earth. More liquid
00:36:16
water. I think Europa, the, one of Jupiter's moons, which has
00:36:23
AAA layer of ice with a s a sober ice ocean underneath it
00:36:27
and a rocky core. We think there 's at least twice as much water
00:36:32
on Europa as there is in all the Earth's oceans.
00:36:35
And when you get to Titan, which has a similar structure, it's
00:36:38
even more, it's probably, you know, three or four times more
00:36:41
than all the Earth's oceans. So even in these little bodies that
00:36:44
we find in the, in the solar system, there's more water than
00:36:47
we have on our oceans. And then the comets themselves are very
00:36:52
rich in water. Cos that's what they're made of.
00:36:55
Ok. Thank you. Scott. Lovely to hear from you. Hope all is well
00:36:59
in the great state of Oregon. Ah, now I got a question from
00:37:03
Paul. It's a text question, but I've managed to lose it. But I
00:37:08
it was a very short question.
00:37:09
I think I can paraphrase but, I'm not even sure if we did this
00:37:13
one before and that's, that's how well my brain's going at the
00:37:15
moment, but he was asking about slingshot around planets and why
00:37:20
we accelerate if we're going in at certain velocities and he, I
00:37:24
think he quoted some sort of formula.
00:37:27
Why would we accelerate around a, a AAA planet or another body.
00:37:32
How does that slingshot effect work?
00:37:36
Someone else might do that question.
00:37:38
Yeah. Yeah, maybe so. I think we did it, towards the end of last
00:37:42
year, but the bottom line is, yes. So that you intuitively,
00:37:49
you think? Ok, this, your spacecraft is being pulled in,
00:37:53
towards a planet by its, the planet's gravity and then it's
00:37:57
leaving the planet and so it should, you know, lose as much
00:38:02
Energy when it leaves, as it gains when it arrives.
00:38:06
And from the viewpoint of the planet itself, that is
00:38:10
absolutely correct. As far as the planet is concerned, the
00:38:14
spacecraft accelerates towards it and then accelerates away or
00:38:19
decelerates away and, and the two balance out. So there's no
00:38:22
change. But the trick is that the planet is moving in its own
00:38:28
orbit around the Sun.
00:38:29
And so when you look at it in, in a coordinate system that
00:38:33
centered on the Sun, what happens is that some of the
00:38:36
momentum of the planet is actually transferred to the
00:38:38
spacecraft and the spacecraft gets a boost, a slingshot boost,
00:38:41
which is really well worth having as we know from the many,
00:38:46
many space flights that have as you have used it. So it's all
00:38:50
about the motion of the planet, not just its its gravitational
00:38:54
attraction.
00:38:54
Does that mean that if you were to get a, a slingshot off a fast
00:38:59
rotating planet, you, you'd get a really good slingshot or
00:39:02
doesn't it work that way?
00:39:04
Fast revolving around the Sun. Yes. You would.
00:39:10
Ok. Ok. So the, the, the revolution around its parent
00:39:13
star that makes the difference, not the rotation of the planet
00:39:18
itself.
00:39:19
Yeah. There, there is actually an effect with the rotation, but
00:39:22
it's a much more subtle one.
00:39:24
And I think we've talked about this before. I think one of the
00:39:29
interesting discoveries is that if you come in from approach the
00:39:34
planet obliquely, in other words, say below its equator,
00:39:38
then that affects the amount of slingshot that you get. So it's
00:39:41
the rotation of the planet that 's now coming into play. That's
00:39:45
for very close slingshots.
00:39:47
And of course, the, the rotation of the planet is you, you get a
00:39:52
good effect of when you're launching a spacecraft from the
00:39:56
surface of the planet, that's right from, from the equatorial
00:40:00
areas because you get a better assist. Is that right?
00:40:02
Yes, exactly. Because you're pushing the, you, you can use
00:40:06
the rotation of the planet. In this case, the Earth, it's about
00:40:10
six hun 1600 kilometers per hour that you get free if you launch
00:40:15
on the equator at our latitudes, it's more like 1400 kilometers
00:40:20
an hour, but it's enough to make a difference and it's enough to
00:40:23
make space launches from these equatorial regions. Very
00:40:27
important.
00:40:28
Ok. There, you go, Paul. Sorry, I lost your question. But I, I,
00:40:32
yeah, II I know we got one like it last year and it's good to go
00:40:37
over it again. It's a really interesting science. Next up we
00:40:39
go to Brisbane.
00:40:43
Good day. What I want Dunks Ash in Brisbane here guys. I just
00:40:47
wanted to touch on a theoretical question.
00:40:50
Floating cities in the atmosphere of Venus, but not
00:40:53
ones that have humans on board, maybe having some algae up there
00:40:58
to transform some of the carbon dioxide due to photosynthesis
00:41:03
and maybe some oh generators that we've been working on, you
00:41:11
know, on Earth, would that clean up some of the atmosphere? And
00:41:13
if so could you potentially over a long period of time cool the
00:41:17
atmosphere? Interested to hear your thoughts?
00:41:19
Think goes, wow. We, we're going down the Martin track of
00:41:24
terraforming again by the sound of it.
00:41:27
It sounds like.
00:41:28
It would be terraforming.
00:41:30
But yeah, it could be too big a project, couldn't it? Or if you,
00:41:34
if you did it over a long, long period of time, maybe eventually
00:41:38
you could make some kind of difference. But Venus is, it's,
00:41:42
it's like trying to cool down an oven with a drop of water.
00:41:47
Yeah, that's right. S so, so yes. So if you've got a million
00:41:51
years, that might be good, it might work. But so Ash raised is
00:41:57
a really interesting point though. Because the upper
00:42:00
atmosphere of Venus is a bit of a hot topic in terms of our
00:42:06
understanding of the potential for living organisms.
00:42:11
That because there are levels in Venus's atmosphere, which are
00:42:17
actually quite equitable, quite cli climatically, what you might
00:42:23
call normal with pressures and temperatures similar to what we
00:42:27
have here on Earth. And so that there, there is a suggested
00:42:32
picture that perhaps within that those regions of Venus's
00:42:36
atmosphere, we could find microorganisms which are
00:42:39
indigenous, they've, they've originated there.
00:42:42
And that you, you'll remember a couple of years ago, there was
00:42:45
great excitement when scientists at the James Clark Maxwell
00:42:49
telescope in Hawaii thought they had detected phosphine in Venus
00:42:53
's upper atmosphere, which would suggest biological origin,
00:42:58
phosphenes not easily produced by rocky planets without life
00:43:03
processes.
00:43:04
So that's you know, it is an area of great interest. Now,
00:43:10
whether you could, you could actually generate enough oh to,
00:43:17
to essentially modify Venus's atmosphere. A a as you are,
00:43:23
Andrew. I'm a bit doubtful about that. It's a big, big project
00:43:28
Venus at the surface has an atmosphere.
00:43:31
And I think I'm pulling this number out of my memory
00:43:34
accurately of, of the order of 100 times the pressure of of
00:43:39
Earth's atmosphere. So there's a lot of atmosphere that you've
00:43:42
got to change. And I in fact think that the idea of
00:43:45
terraforming Venus really is a nonstarter under any
00:43:48
circumstances because we don't know too much about the
00:43:51
geological state of the surface.
00:43:53
There are, we know lots of, lots of, we think there are active
00:43:57
volcanoes on Venus. There's evidence to suggest that there
00:44:01
might well be, which is, yep. Putting it into a different
00:44:06
perspective. Yeah. Great suggestion though. Asher. I like
00:44:09
your, I like your thinking.
00:44:10
He's always got some interesting ideas. Has Ash. I'm not so sure
00:44:14
about the Watto and Dunks show though. That, that might, I
00:44:18
didn't see that's how he started off. Hello, Wad and Hello, wo
00:44:22
and Dunks.
00:44:23
Should be the other way around. Shouldn't, it doesn't matter. Do
00:44:27
Dunks and Watto.
00:44:29
Oh, no, I think it's got more of a ring to it the other way and
00:44:32
you're the star. I'm just the idiot, push up the buttons and
00:44:34
I'm not doing it very well today. But, thanks, Ash. Great.
00:44:40
Great to hear from you. Now, we've got 11 more quick
00:44:44
question. I know we only usually do two or three but, this one
00:44:47
came in via our Spotify platform and it's a, it's a, it's a one
00:44:54
liner. Hello, if stars are made of, the same stuff as humans are
00:45:01
we stars. I am six. That's from Nomi.
00:45:04
Hi Naomi. Great to hear from you. It's great to hear some
00:45:08
young listeners, getting involved. So stars are made of
00:45:13
the same stuff as humans are we stars? Now, Naomi, that reminds
00:45:19
me of a documentary the BBC did some years ago called the Stars.
00:45:24
And there was one episode dedicated to the Sun.
00:45:28
And the big revelation was when humans discovered that the Sun
00:45:33
was actually a star, like all the other ones twinkling in the
00:45:36
heavens. And the, the, the show concluded with the, with the the
00:45:43
claim that we were all made of stardust. So my answer to you is
00:45:49
yes. What do you say, Fred?
00:45:51
Yes. Being made of the same stuff as something doesn't make
00:45:54
it the same stars is a comment.
00:45:59
Although we do label people.
00:46:00
That well, actually, actually. Yeah. No, no, is a star.
00:46:03
Definitely. There's no question about that. Great question. But
00:46:08
yes, so but, but the, you know, it's the correct thinking
00:46:12
because of the material that makes up you and me, and
00:46:18
everybody else in the world.
00:46:20
I mean, the most important things are carbon hydrogen,
00:46:24
oxygen, nitrogen, a few other things, you know, s small traces
00:46:28
of other elements. But that's what we're made of and all of
00:46:33
those except hydrogen come from the inside of stars. Because
00:46:38
these chemical elements are all produced in the cores of stars.
00:46:42
So they, they, they were generated in the cores of stars.
00:46:45
The stars fell, fell apart one way or another at the end of
00:46:49
their lives. And that put the raw material for humans into
00:46:53
space where other stars formed and basically formed planets.
00:46:56
And suddenly here we are the the hydrogen, most of it came from
00:47:04
the Big Bang itself. So your, your hydrogen is even older than
00:47:10
your oxygen, nitrogen and carbon.
00:47:13
Nitrogen. Sorry, hydrogen is the oldest of the elements because
00:47:17
it was formed. Its nuclei were formed in the aftermath of the
00:47:20
Big Bang. So, since most of us, most of what humans are made of
00:47:27
is water, I can't remember. Is it 75% water?
00:47:34
That means and so in a water molecule, you know, two out of
00:47:42
the three atoms in a water molecule are hydrogen. So two
00:47:46
thirds of your 75% which is 50% of the atoms in your body come
00:47:51
from the Big Bang. Why you feel old these days? You know, the
00:47:57
13.8 billion year old hydrogen?
00:48:00
Wow. Well, that explains the aches and pains. Thank you,
00:48:04
Naomi. Great to get your question and, and please, if
00:48:08
you've got any more questions, send them to us, we'd love to
00:48:11
hear from more of our young audience of which there are,
00:48:14
well, we now know two. But yeah, always good to get feedback
00:48:19
from, from everybody.
00:48:20
If you do want to send us feedback or some questions or
00:48:23
send us a what if or anything along those lines. You can do
00:48:27
that through our website, Space Nuts, podcast.com or Space Nuts
00:48:31
dot IO. Click on the links to send us your text or audio
00:48:35
questions, Fred. That brings us to the end of another show.
00:48:38
Thank you, sir.
00:48:40
Well, it's a pleasure. It's been a very stimulating show. I only
00:48:45
made six mistakes in this one, but that's all right.
00:48:49
Yeah, we'll, we'll get feedback on that. I'm sure we'll be, we
00:48:52
are.
00:48:54
As I always say, we only strive to be great, but it's great that
00:48:59
we've got listeners who, you know, are happy to pick up on
00:49:03
the, on the whole because I, I, I'm always willing to be
00:49:07
corrected as I am, which I'm very much used to.
00:49:11
Thanks Fred as always. Catch you on the next episode. Sounds
00:49:14
great. Take care, Fred Watts, an astronomer at large and Hugh in
00:49:18
the studio. I wish all the very best in editing this particular
00:49:22
episode, given all the, all the technical dramas we had. And
00:49:26
from me, Andrew Dunley. Thanks for your company. Catch you at
00:49:29
the very next episode of Space Nuts. Bye bye.
00:49:32
Nuts, available at Apple Podcasts, Spotify, IHeartRadio
00:49:41
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00:49:45
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00:49:47
This has been another quality podcast production from bits dot
00:49:50
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00:49:56
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