Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Comet Conundrums, Cosmic Shutdowns & The Mars Remains Controversy

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Comet Conundrums, Cosmic Shutdowns & The Mars Remains Controversy · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Andrew Dunkley: Hello again. Thanks for joining us. This is
0:02
Space Nuts. My name is Andrew Dunkley, your
0:04
host. It's great to have your company. And on
0:07
this episode we're going to take another look
0:09
at 3i Atlas and uh,
0:12
it's not a positive story, uh,
0:15
and we'll explain why. And it correlates with
0:18
another yarn we're going to have about the US
0:20
government shutdown and the impact that that
0:23
is having on all things
0:25
space related at the moment. Uh,
0:28
there's also a very controversial story and
0:31
uh, the, the two sides in this and certainly
0:34
not uh, on the same page. And that is sending
0:37
human remains to Mars,
0:40
uh, and new evidence of the formation of the
0:42
moon. And we're going to have a quick chat
0:44
about the potential for, wait for it.
0:47
A gnab gib. That's all
0:50
coming up on this episode of space nuts.
0:53
15 seconds. Guidance is internal.
0:56
10, 9. IGN
0:59
sequence star space nuts.
1:00
Jonti Horner: 5, 4, 3. 2. 1.
1:02
Andrew Dunkley: 2, 3, 4, 5, 5, 4, 3, 2,
1:05
1. Space nuts. Astronauts report it
1:08
feels good. And joining us to
1:11
unpackage all of that is Jonti Horner,
1:14
professor of astrophysics at the University
1:16
of Southern Queensland. Hi Jonti.
1:18
Jonti Horner: Morning. How are you going?
1:19
Andrew Dunkley: I am very well and you?
1:22
Jonti Horner: I can't complain too much. I'd have been
1:23
better if football results had been
1:25
different. Um, but you know, it's a new week.
1:27
Mondays are always terrible anyway, so that
1:29
was just added salt in the wounds.
1:31
Andrew Dunkley: There was an Australian band who once, uh,
1:33
recorded a song called Monday's Expert
1:36
and it was all about what you talked about
1:39
on Monday after the sport was finished on the
1:41
weekend. It's very clever song.
1:44
Uh, we should get straight into it because
1:47
there is so much, so much to talk about
1:49
today. And this first one is
1:52
uh, Three Eye Atlas. Now we've talked about
1:55
it a couple of times, but this angle on
1:58
the story is uh, a bit of a downer
2:01
because we talked about how, uh,
2:03
there would be great observations of three I
2:06
Atlas from Mars. And that data was really
2:09
going to be exciting and being looked forward
2:11
to. It has not been released
2:14
and for a very unfortunate reason.
2:18
Jonti Horner: Yeah, this is the ongoing story of the thing
2:21
that is definitely not aliens. Basically.
2:24
Now should be said straight away, the Comet
2:26
3I Atlas came quite close to Mars.
2:29
Not perilously close by any means. There was
2:32
never a risk of a collision. Um, whilst it
2:35
was in hiding, it was on the far side
2:38
of the sun from us, lost in the daylight sky.
2:40
And so in order to track it through its
2:42
perihelion passage, people have been very
2:44
keen to Keep an eye on it using spacecraft at
2:47
Mars. Now we have got images back from
2:49
European spacecraft and from the Chinese
2:51
Tianwen mission, but
2:54
NASA have been notably silent.
2:57
Now Avi Loeb, who is continually
2:59
pushing the narrative of aliens and
3:02
a Republican representative in the US called
3:05
Anna Paulina Luna are uh, crying
3:08
foul. They're kicking up a fuss to try and
3:10
keep the alien narrative in play. I think as
3:12
much as anything else saying it's disgraceful
3:15
that NASA have been so quiet. They should be
3:17
releasing the images. What are they not
3:18
telling us? NASA, come on, release the images
3:20
now. And I'm paraphrasing a little bit there,
3:23
but they're kicking up a fuss about the fact
3:24
that, you know, NASA haven't released
3:27
anything and the comet was closest to Mars on
3:29
3 October. These spacecraft have gathered all
3:31
the data. Why are they not releasing the
3:32
images? There must be something that's
3:34
hidden. Ignoring the fact, of course,
3:36
Europeans and the Chinese are releasing
3:37
images. Mhm. What really
3:41
infuriates me about this, to be honest, is
3:43
that, uh, there is a very good reason that
3:45
NASA has not released anything. It's the same
3:47
reason that the wonderful Astronomy Picture
3:49
of the Day website that I check most days has
3:51
not updated since the start of October. There
3:54
is a US government shutdown happening at the
3:56
minute. NASA staff are considered non
3:58
essential, which means more than 15,000 of
4:00
them are furloughed. They are not getting
4:03
paid, they're not allowed to work. But beyond
4:05
that, if they do anything that looks like
4:07
they're working in a professional capacity,
4:09
they run the risk of being sacked. Gosh,
4:11
straight up. And I've got colleagues in the
4:13
US who are suffering from this, you know,
4:14
collaborators of ours on our Planet Search
4:16
program. They sat at home twiddling their
4:19
thumbs, wondering where the next meal's
4:21
coming from, living off the earnings of their
4:22
partners. If they have partners. And uh, they
4:25
cannot do anything. They can't get this data,
4:27
they can't comment on it. Now,
4:30
you know, you could give Avi Loeb a little
4:33
bit of benefit of the doubt. I'm a bit loath
4:34
to do that, but maybe he hasn't twigged that
4:36
there's a government shutdown happening in
4:38
the country that he's in that's affecting his
4:39
colleagues in his department at Harvard.
4:42
He may not have noticed, you know, I mean,
4:45
he's been that busy telling everyone it's
4:46
aliens, perhaps he's not talking to his
4:48
colleagues or perhaps they're not talking to
4:49
him. But for a U.S. republican
4:52
representative who sits in the House,
4:55
who is Part of the reason that there is a
4:57
shutdown to be spinning essentially
5:00
lies for political gain under the. You've got
5:03
to assume that she knows that NASA can't talk
5:05
about this because she understands the
5:08
shutdowns on. Right. They're causing this.
5:10
Andrew Dunkley: Yeah.
5:10
Jonti Horner: The only thing I can assume here is that she
5:13
is convinced that her voter base
5:16
are anti science and therefore it's easy
5:18
points to score and it's like kicking
5:20
somebody while they're down. Yeah, it's
5:22
really not on. And there is no story here.
5:25
NASA are not talking about the comet because
5:27
nobody's there. The phones are on the hook,
5:29
nobody's in the office. It isn't anything to
5:32
do with aliens. It isn't that there's
5:33
anything untoward or dodgy going on.
5:37
And added evidence for that is the fact that
5:39
the other space agencies have released
5:40
images, they've release their data. Uh,
5:43
we've also got now three eye atlases starting
5:46
to get far enough away from the sun m that
5:47
people on Earth are starting to get some nice
5:49
images again. So a lovely one on Facebook in
5:51
the Comets group this morning showing
5:53
beautiful structure in the tail of comet
5:55
atlas and things like this. So the
5:58
information's there. They're just cherry
6:00
picking that NASA required to try and push
6:03
this false narrative. And it's just getting
6:05
tiresome to be honest. But it's very
6:07
offensive in terms of the situation that the
6:09
staff at Nasser are under that people could
6:12
come out with such hockey.
6:14
Andrew Dunkley: They're between a rock and a hard place
6:15
because they can't talk about it because
6:18
they've been, to use the Australian
6:20
vernacular, laid off, they're not getting
6:23
paid. If they do say something,
6:26
they're in breach and could lose
6:29
their jobs. I mean, so they're having
6:32
to listen to this rubbish that's coming
6:34
out about them and uh,
6:37
all they can do is sit on their hands. I
6:40
think it's horrendous. And
6:43
I can't imagine this happening in Australia.
6:45
There's no way that
6:48
any government in Australian history would
6:51
get away with this. If the current
6:54
government shut down all the government
6:56
departments and stopped paying people,
6:59
there'd be rebellion.
7:00
Jonti Horner: Well, not just that. I uh, was under the
7:02
impression that the US prided
7:05
itself on its commitment to free speech.
7:08
And yet you're not allowed to do any work and
7:10
you can't speak to anybody because we're
7:13
having a fallout in the, you know, in the
7:15
congress that doesn't speak to free speech.
7:18
For me, the idea that if you raise your hand
7:20
and counter this
7:23
absolutely cobbler's narrative that's coming
7:25
out, you'll lose your job.
7:28
How bizarre is that? I mean, uh, you know,
7:30
that's like something from some kind of
7:32
movie, like 1984 or something.
7:35
Andrew Dunkley: Yeah, that's exactly what it's like. Yes. Um,
7:38
you can be put to death because you, you, um,
7:41
gave somebody a check.
7:42
Jonti Horner: Yeah, it sounds hyperbolic, but it's,
7:45
it stretches beyond NASA. We're aware of it
7:47
from NASA from the point of view of this
7:49
podcast, but all the government agencies are
7:51
into that.
7:51
Which will lead us into the second item
7:54
shortly. But it's a bizarre situation.
7:57
And you know, I'm not in the us I'm not in
7:59
the nitty gritty of it. I'm certainly not
8:01
involved in the politics of what's going on.
8:02
But it makes your head hurt that the most
8:05
successful space agency on the planet with
8:07
all these fabulous missions, can't do
8:10
anything. And you know, it may well be that
8:12
some spacecraft will be irrevocably lost
8:14
because of this. There were discussions about
8:16
Juno around Jupiter. The fact that its
8:18
funding ended just before this, so they
8:21
couldn't even have somebody on tick over, uh,
8:23
for it because the funding had ended. So
8:25
nobody can do anything to put it into
8:26
maintenance mode. What odds that when the
8:29
shutdown finally finishes, Juneau is
8:30
incommunicado forever.
8:32
Andrew Dunkley: Yeah, yeah. And that's a terrible waste of
8:35
hardware and money, really.
8:37
Jonti Horner: Dollars down the drain.
8:39
Andrew Dunkley: Yeah, absolutely.
8:40
Let's move on to that next story because it
8:42
does correlate exactly with what we've been
8:44
talking about, the US government shutdown and
8:47
how it's affecting flights. But it's also
8:50
affecting like domestic, uh, airline flights,
8:52
uh, but it's also affecting rocket, uh,
8:55
launches. And that is, um, going to have
8:58
an impact on a couple of big missions that
9:01
are planned.
9:02
Jonti Horner: It is. So the. I saw this actually on the
9:04
BBC website on Sunday morning yesterday
9:07
morning as we're recording this, that the big
9:10
article, there was more than 1400 flights
9:12
canceled in the past 24 hours because air
9:15
traffic control is effectively on a go slow
9:17
in the US at the minute. Now,
9:20
um, that is kind of understandable
9:23
because the air traffic control people, guess
9:25
what, they're government employees and
9:27
there's a shutdown. I mean, who'd have
9:28
thought it? And it's been exacerbated because
9:30
I think there was a very high profile
9:31
aircraft crashed last week. So there's been a
9:34
lot of air issues,
9:37
um, in the news. Anyway,
9:41
um, yeah, I was just checking updates on
9:44
that. That's why I was looking over to the
9:45
other screen there. But you're basically
9:47
what's been happening is uh, to deal with the
9:50
ongoing shutdown, the faa, which
9:53
is a Federal Aviation Administration,
9:56
is bringing in increased restrictions on who
9:59
can use airspace at what time to try and
10:01
lighten the load on the people who remain in
10:04
the air traffic control stuff to keep it
10:06
manageable. And um, this is entirely
10:08
responsible, it should be said, you know, if
10:10
I'm on a plane coming in to land at an
10:12
airport, I want air traffic control to be on
10:14
top of what's going on and if they've got
10:15
fewer people there it makes sense to lighten
10:18
the load so that they can manage things and
10:21
so you don't run into catastrophes. Totally,
10:23
totally reasonable. Where it impacts us from
10:25
a space point of view is that
10:28
starting today, um, Monday the
10:31
9th, sorry, Monday the 10th US time.
10:35
So for us here in Australia that's late
10:36
Tonight there is a new restriction coming
10:39
in as part of this airspace management thing
10:42
where any commercial rocket
10:45
launchers will be limited to only occur
10:48
between the hours of 10pm EST and um,
10:50
6am EST. So that's an eight hour
10:53
window every day in the middle of the night
10:56
when airspace is quietest
10:59
basically. Now that's going to have
11:02
a little bit of an impact on the research
11:04
side of things and I'll come to that in a
11:05
minute. The main impact will probably be on
11:08
people like SpaceX of course who have been
11:10
accelerating their launch schedule to get
11:12
more and more Starlink satellites into the
11:15
skies, to expand their Internet
11:18
coverage with Starlink. And um, they're going
11:21
to be hit by this because suddenly they can
11:23
only launch in this eight hour slot every
11:25
day. And um, that will obviously impact what
11:27
orbits they can launch into and um, what
11:29
launch windows they can meet and stuff like
11:31
that. So that's going to be problematic. Now
11:33
a bit in the report here, I'm actually going
11:35
to read this out and quote this because this
11:37
again, probably from an Australian and
11:39
formerly British perspective, really make my
11:41
head hurt. It says during the
11:43
shutdown all federal employees deemed non
11:46
essential are furloughed. That's the NASA
11:48
people of course. So those whose job falls
11:50
into the essential category are uh, still
11:53
required to work but are uh, not currently
11:55
getting paid. They must
11:58
rely on back pay once the government reopens.
12:00
So for NASA that means 15,000 people staying
12:03
home and who can't comment. Um, but in
12:05
contrast 95% of employees of the Transport
12:08
Security Administration are considered
12:10
accepted and have to continue to work
12:13
without pay since the shutdown began on 1st
12:16
of October. So not only are you,
12:19
that makes my Head hurt, huh? You've got to
12:21
work, but you can't earn any money. But we
12:23
will give you some back pay in the future. It
12:25
doesn't help you buy your food.
12:27
Andrew Dunkley: No.
12:27
Jonti Horner: You know, it doesn't alleviate the stress,
12:30
particularly when people are doing it hard.
12:32
And you can understand that this will
12:34
probably contribute to, uh, the people
12:36
running air traffic control and stuff like
12:39
that, not necessarily being in the best shape
12:40
to do their best possible job. You've got to
12:43
take account of the fact that people are
12:44
human and with the stresses and strains going
12:47
on, it makes life challenging. So this
12:50
shift to the rules is entirely
12:53
reasonable, it's entirely well thought out,
12:55
and it's a natural consequence of the
12:57
problems that are going on there. But it will
12:59
have an impact on the burgeoning space
13:01
industry from the US Particularly with
13:03
launches from Florida and California impacted
13:05
by this. Basically, you can't launch unless
13:08
it's the middle of the night. Now, there was
13:11
a launch scheduled in the early hours of
13:14
this morning, Australia time, which is the
13:15
escapade mission. It's a NASA mission to
13:17
Mars. And I'm not across the politics well
13:20
enough to understand quite how that mission
13:22
was going to be allowed to launch, given that
13:24
NASA staff are all on furlough. But I think
13:26
it was probably because they got the
13:28
spacecraft to the launch provider, Blue
13:30
Origin, prior to the shutdown.
13:32
Um, so Blue Origin, we're hoping to launch
13:34
that this morning before these regulations
13:36
come into place, because we currently have
13:38
the launch window to Mars that only comes
13:41
around every 26 months or so, just
13:43
opened up. But to launch to Mars at the
13:46
minute, you've got to launch in the daylight
13:47
hours. So there was this risk
13:50
there that if that launch was scrubbed, if
13:53
the launch was canceled for some reason or
13:54
postponed weather, you know, maintenance,
13:56
security, whatever, then suddenly they run
13:59
foul of this change to the regulations. Now,
14:02
I've just clicked over to Space.com, which
14:05
is where, incidentally the information I
14:07
quoted earlier on came from. Um, and it looks
14:10
like Blue Origin delays launch of New Glenn
14:12
rocket carrying NASA Mars probes may seek
14:14
exemption from the FAA in order for next try
14:18
because this is NASA's first attempt to
14:20
launch something to Mars for five years. If
14:24
the shutdown lasts longer than the launch
14:26
window is open and, um, an exemption is not
14:29
granted. This mission will be delayed by 26
14:31
months.
14:34
Andrew Dunkley: And that'll be expensive too. Um,
14:37
you do not want to wait two years to have
14:39
another crack.
14:40
Jonti Horner: But, uh, if nothing else, you have to keep
14:43
all the people who have the expertise on
14:44
board keep paying two years While they do
14:47
other things, waiting for this to
14:51
finally happen. So it's all a little bit of a
14:54
car crash, unfortunately.
14:55
Andrew Dunkley: It sure is. Uh,
14:58
do we have any idea how long this shutdown is
15:00
going to last?
15:01
Jonti Horner: It's already the longest on record. But what
15:04
has shrugged me from the outside looking in,
15:06
and I don't know if this is true on US
15:08
networks and on US news sessions, but in the
15:11
first few days of this it was all over the
15:13
news. When I logged on on the morning I
15:14
opened up BBC News website, ABC News website,
15:17
and it was front page news. Now it's
15:20
vanished into the background. Because it's
15:22
old news.
15:23
Andrew Dunkley: Yeah.
15:23
Jonti Horner: And so it's not at uh, the front of the news
15:25
cycle. So I'm not seeing, I've not been able
15:28
to get any indication of. Are they close to
15:30
agreeing a deal? Are they as far apart as
15:32
ever? What's going on? It's already the
15:34
longest one on record. Um, and
15:37
certainly there hasn't been anything in the
15:38
news about a magical solution coming up. So
15:41
it's a case of watch this space, but possibly
15:44
a case that if you are in the U.S. maybe you
15:46
should be kicking up a fuss about this
15:47
because it's just so bizarre and
15:49
unconscionable.
15:51
Andrew Dunkley: Yes, it is. That's, that's probably the best
15:53
way to describe it. But uh, as I mentioned
15:55
before, if this were to happen in um, in the
15:58
UK or Australia, it just wouldn't be
16:00
tolerated. I don't know.
16:02
Jonti Horner: I mean people's jobs and livelihoods
16:05
are, ah, not reliant on the passing of a
16:07
budget immediately. In the same way there's,
16:09
I think that's fundamentally what it is. As
16:11
soon as this happens and they don't sign the
16:13
bull, the money dries up.
16:14
Andrew Dunkley: Well, we've got different uh, powers in
16:18
the UK and Australia. So if a government did
16:21
this, um, the opposition would be able
16:24
to go to the
16:26
palace. They'd be able to go to the palace,
16:28
the Governor General who's the representative
16:30
of the King, and it's happened in our
16:33
history before. They can just turn around and
16:35
sack the government.
16:36
Jonti Horner: Yeah. And, and um, false. An election.
16:38
Andrew Dunkley: Exactly. That happened in
16:40
1977, was it?
16:43
Yeah, it was a while back. But uh, yeah, it
16:45
could. It's a different constitution, a
16:48
different, uh, totally different ball game in
16:50
America. Um, and uh,
16:53
yes, they've got um, they've got to find
16:55
another way of dealing with it, I suppose.
16:56
But uh, yeah, very, very sad news indeed. And
16:59
uh, a lot of, a lot of jobs on the line and a
17:01
lot of Projects that are basically on hold
17:06
and we don't know when that
17:08
might ease.
17:10
Jonti Horner: But, uh, you'll certainly big disruption for
17:12
people as well.
17:13
Andrew Dunkley: Yeah, absolutely.
17:14
Yeah.
17:14
Jonti Horner: Well, you know, just at our lives.
17:16
Andrew Dunkley: Now, just putting bread and butter on the
17:18
table. That's the bottom line, isn't it? How
17:21
many people are struggling with that? It's
17:22
very sad. This is Space Nuts with
17:25
Andrew Dunkley and Jonti Horner.
17:31
Three, two, one.
17:34
Space Nuts. Now, we, we just talked
17:37
about, uh, a mission to Mars that, uh, was
17:40
supposed to lift off and hasn't because of,
17:42
of those government shutdowns.
17:44
But, uh, this next story is just as weird
17:47
and just as crazy and just as
17:51
difficult to accept and very, very
17:54
divisive. And that is the plan to send
17:56
human remains to Mars?
17:59
Jonti Horner: Yes.
18:00
Andrew Dunkley: I would not want my human remains after
18:03
I'm gone to be sent to another planet. This
18:05
is my planet. This is where even when I'm
18:08
dead and gone, this is where I want to be. I
18:10
don't understand this at all.
18:12
Jonti Horner: No, neither do I. And I mean, you know, I'm,
18:14
I have no religion to speak of. I have no,
18:17
no expectations what happens to me after I'm
18:20
gone. But, you know, I'm used to the idea
18:22
that people would want their remains
18:24
somewhere, that those who remember them can
18:26
go there and celebrate their lives. Right?
18:28
Andrew Dunkley: That's, that's the bottom line as far.
18:29
Jonti Horner: As I' commute to go to Mars to pay your
18:32
respects and leave a flower. You know,
18:35
this makes my head hurt, huh?
18:38
In huge ways. And there's a bit of backstory
18:41
to this. There's a company called Celestis
18:44
in the US who seem to have this
18:46
goal of putting corpses into space
18:49
or putting ashes into space. You know,
18:51
whether that's your beloved pet or whether
18:53
it's your beloved grandma, um, there is a
18:56
little bit of a precedent for this. The great
18:58
planetary scientist Eugene Shoemaker,
19:01
who possibly most famous for discovering
19:03
comet Schumacher Levy 9 that hit Jupiter in
19:06
the 1990s, um, also
19:08
a big, big part of the history and heritage
19:10
of Meteor Crater in Arizona, and confirming
19:12
that that actually is an impact feature, was
19:15
involved to some degree in the discussions of
19:16
the Shikta Lub impact that killed the
19:18
dinosaurs. Some of his ashes went on the
19:21
Lunar Prospector mission and landed on the
19:23
moon. So some of his ashes were on the moon.
19:25
And that caused a little bit of a ripple.
19:27
There was a bit of discontent. But a few
19:28
years ago, um, back in 2024,
19:31
the same company, um, tried
19:35
to send a package as part of one of the
19:37
missions to the Moon, um, to put people's
19:40
ashes on the surface of the moon. Now,
19:44
this caused a lot of upset. And the
19:47
reason it did is that it touched on the
19:49
cultural sensitivities of different groups
19:51
around the planet who have different belief
19:53
systems and hold the night sky in very
19:56
high regard, who have a very strong cultural
19:58
connection to that. And that's true of people
20:00
across the globe. And what tends
20:03
to happen with these kind of companies is
20:04
they don't so much. Um, well, there
20:07
is a saying that it's better to ask
20:09
forgiveness and permission, but I think these
20:11
companies don't even ask forgiveness after
20:12
the fact. But there isn't much evidence that
20:15
they attempted to contact and communicate
20:17
with different people around the world
20:20
to see whether this would be problematic or
20:22
offensive. Now, it kicked off in early
20:25
2024 because the Navajo Nation
20:28
in the US hold the moon as an incredibly
20:31
sacred place in the sky. And to them,
20:34
putting human remains on the moon is
20:36
testament to sacrilege. It's desecration. It
20:39
is incredibly offensive and hurtful to them.
20:41
So they came out very strongly against this.
20:44
I think they put protests in. I think they
20:46
were even looking at court cases. The
20:49
CEO of Celestis,
20:52
in response to that, was
20:55
quoted, um, in my
20:58
eyes, I hear this. I read this as being
21:00
incredibly dismissive and incredibly lacking
21:02
in cultural competency and awareness. He just
21:05
came out and said, we're aware of the
21:06
concerns expressed by Mr. Nigren,
21:09
who's the, um, leader of the Navajo
21:12
Nation, who was raising it. We're aware of
21:14
his concerns, but we don't find them
21:16
substantive. We reject the
21:18
aspiration that our memorial
21:21
spaceflight mission desecrates the moon, just
21:24
as permanent memorials for deceased are
21:25
present all over planet Earth are not
21:27
considered desecration. Our memorial on the
21:29
moon is handled with care and reverence. It's
21:32
a permanent monument that does not
21:33
intentionally eject flight capsules to the
21:35
moon. So touching and fitting celebration.
21:37
The exact opposite of desecration.
21:40
Which seems to me like he's not at all
21:42
interested in the views of people from other
21:44
cultures and with other belief systems. Um,
21:46
and I found that, to be honest, a very
21:48
offensively worded statement, given that
21:51
I know of the problems we have here in
21:54
Australia with dealing with the traditional
21:57
owners of land here. There's a lot of
21:58
problems there. Uh, there's ongoing issues
22:00
like sacred sites getting blown up by mining
22:02
companies, things like this. This is not
22:04
unprecedented.
22:05
Andrew Dunkley: Yeah.
22:06
Jonti Horner: But there's this
22:08
ongoing struggle to gain awareness
22:11
of the best way to manage things, where
22:14
different cultures have differing opinions
22:16
and to get the Best result for everybody. And
22:19
we've seen in the, over the uh, years really
22:21
good examples of where this has been managed
22:23
well. And the Square Kilometer Array in
22:24
Western Australia is held up as like the
22:27
shining light of how to manage these kind of
22:29
frictions and bring people on board and do it
22:31
well. There have been examples that are
22:33
equally um, illuminating at the
22:36
opposite end of the spectrum. The thirty
22:37
Meter Telescope on Hawaii is a good example
22:39
of where it's been managed badly. And I think
22:41
this from Celestis of yeah,
22:44
Solestice is much the same thing.
22:47
So that's the background. Here's a company
22:49
that wants to go ahead and put wealthy
22:51
people's remains on celestial bodies. And
22:54
they don't really care what anybody else
22:55
thinks because if we're doing it can't be
22:57
desecration. Right. Yeah. Now the latest plan
23:00
is to send, they are opening up
23:03
reservations. You've got to pay 10% upfront,
23:06
which is a good way of making a bit of money,
23:09
um, to send your ashes to Mars. They've got
23:11
their Mars300 project and
23:14
that aims to have something that flies as a
23:16
secondary payload on one of the future Mars
23:17
missions. They've not identified a mission
23:19
they're going to bolt their capsule onto yet,
23:21
but the goal is to launch this in 2030 as
23:24
their first burying people on Mars
23:27
attempt. Now they're charging a huge amount
23:29
for that. I don't know what a normal burial,
23:32
a normal funeral will cost. I'm very
23:33
fortunate that I've never had to organize one
23:35
myself. But they are charging people
23:38
US$24,995
23:41
for the privilege of having some of their
23:43
ashes put in a capsule and sent to Mars. 10%
23:46
of that has to be upfront. Now there's a lot
23:48
of aspects to this that are weird beyond
23:51
the cultural side of it, which I find very
23:54
distasteful. It's a bit different if we've
23:56
had those conversations and um, people are on
23:58
board and you've confirmed that there is no
24:00
culture on Earth that would find Mars sacred
24:02
and find this inappropriate.
24:06
That doesn't appear to be the case. But even
24:07
ignoring that, one of the big costs for
24:10
sending missions to Mars and
24:13
to Europa and to all these other places that
24:15
we think could be potentially habitable is
24:17
something called planetary protection. It's
24:20
basically the fact that if you're going to
24:22
anywhere where there is even a remote
24:24
possibility that human or
24:28
Earth, um, based life could survive in
24:31
those conditions, even if it's a very remote
24:33
possibility, then there is an extra burden
24:36
of sterilization to
24:38
reduce, minimize, or even try to
24:41
absolutely prevent any possibility of
24:43
contamination of that environment. Now, it's
24:45
very important for Mars and Europa and
24:47
everywhere, Partially because we don't know
24:50
if there's life there, but also because if
24:53
we want to find out if there is life there,
24:54
the last thing you want to do is get a false
24:56
positive because you've detected some Earth
24:58
bacteria that have been spilled there. Yes.
25:00
Now, I think the planetary protection thing
25:03
personally is a little bit overblown Purely
25:06
because life from Earth will have been
25:08
scattered across the solar system repeatedly
25:10
over the years through meteorite impacts on
25:13
Earth, uh, knocking bits of the Earth off
25:14
into space and things transiting between the
25:16
planets. That's a process called panspermy,
25:19
which sounds utterly science fiction, sounds
25:22
like it couldn't work. But every experiment
25:24
anybody does on Earth kind of shows that that
25:26
actually would work. And if it would work,
25:29
over 4 billion years of the solar system,
25:32
the Earth will have sneezed repeatedly on the
25:34
other planets and the moons in the solar
25:36
system and basically inoculated them with
25:38
terrestrial life. So it's already there, if
25:41
it is there. But the other thing is, if we
25:43
take life to Mars and there is life there,
25:45
the life that's on Mars is adapted to those
25:47
conditions. Our life will not be. So I
25:50
think there's a little bit more spent on
25:52
planetary protection than is perhaps needed.
25:55
But at the same time, it's better to be safe
25:57
than sorry. So I understand why, but it
25:59
seems to fly in the face of planetary
26:01
protection to just send
26:04
human ashes to Mars. I mean,
26:07
that feels like a pretty high risk with no
26:10
reward. I can understand if you're sending a
26:12
scientific mission, you've got the
26:14
instruments that get stabilized. There is a
26:16
reason to have those instruments there. And
26:19
then you weigh the reward and the cost.
26:22
Effectively, I don't see
26:24
any reason other than vanity for us to
26:27
drop human ashes on Mars. I don't see any
26:30
benefit to humanity long term, um, or to
26:32
science.
26:33
So I don't see why you would do something
26:35
like that. That brings with it the incredible
26:37
risk of something going wrong, of those ashes
26:40
actually being scattered on the surface
26:41
rather than being contained in a container.
26:44
It just seems a bit like the
26:46
reflect orbital stuff we talked about the
26:48
other. I was about to bring that up. Yeah,
26:50
yeah. It's one of these things where, um.
26:53
What's that famous quote? It's like people
26:55
spent so much time figuring out how to do
26:57
something that they never asked whether they
26:58
should. It feels like one of those.
27:00
Andrew Dunkley: It does, doesn't it? Very much so. Um,
27:03
yeah, I must admit it's a. It's a big head
27:06
scratcher, and I just don't see any
27:09
logic in this whatsoever. And,
27:12
uh, and yet I'm sure they will get. They will
27:14
get people signing up.
27:16
Jonti Horner: That's.
27:17
Andrew Dunkley: They will do.
27:18
Jonti Horner: And my, my criticism here is not for the
27:20
people who sign up. It's a bit like the
27:23
many different things you see online where
27:24
you can name a star after somebody. And of
27:26
course, that is not an official naming of the
27:29
star. You might get a certificate with the
27:31
name on, but it's not an official
27:33
astronomical name. It won't appear in any of
27:34
our catalogs. But I'm. Even though I
27:37
will criticize very vocally the companies
27:39
that run those kind of businesses,
27:43
I have strong opinions there. I'll never
27:44
criticize someone for signing up to do it.
27:46
Because when you're grieving and you want to
27:49
do something to commemorate someone, or when
27:50
you want to do something nice for someone to
27:52
celebrate them, it sounds like such a lovely
27:54
idea. And this is a bit like that. I'm not
27:57
going to criticize the people who want to
27:59
send their puppies ashes to space or who want
28:01
to send Grammy's ashes to space. If you think
28:03
that's a lovely way to commemorate them on
28:04
something special, more power to you. Not at
28:07
all offended by that. My problem is with the
28:10
people who are capitalizing on people's
28:12
grief and riding roughshod, um, over the, uh,
28:15
cultural sensitivities of different people
28:17
around the planet because they can, because
28:19
there's nothing there to stop them. And I
28:21
should say I'm trying to be as sensitive
28:23
about this as I can. Though I, you know,
28:25
quite happily admit that I'm a white British
28:27
male, Australian male. Now I've got the
28:29
passport. These cultural issues don't
28:31
directly impact me, but I work with people
28:34
who spend a lot of their time looking into
28:36
this, who have, for example, spent a lot of
28:39
effort working with the traditional owners
28:41
here in Australia to learn more from their
28:42
knowledge and to work with them and repair
28:45
the damage that's been done in the past. And
28:46
there are people actively trying to make the
28:47
world a better place. And things like this
28:50
just seem to ride roughshod over that.
28:52
Andrew Dunkley: Yes, that is exactly what it sounds like, for
28:55
sure. We'll, um, certainly hear more about
28:57
this, uh, down the track. Hopefully, uh,
29:00
common sense will prevail, but I suspect not.
29:03
This is Space Nuts with Andrew Dunkley and
29:05
John T. Horner.
29:10
Jonti Horner: 0G. And I feel fine.
29:12
Andrew Dunkley: Space Nuts. This, uh, next story is
29:14
a little bit more positive or Is it? Uh,
29:18
yeah, I think it is. Um, this is, this is
29:20
based on, uh, some evidence that's been dug
29:23
up, literally in Western Australia,
29:26
and it focuses on new evidence about
29:29
the formation of the moon. I, I do like this
29:32
story, I must say.
29:33
Jonti Horner: It, it's a fabulous one. It's good to get to
29:35
something cheerful now that I've got all my
29:37
angst about the football out by ranting about
29:39
stupidity. We can to some good science and
29:41
some good fun stuff.
29:42
So, yeah, sorry everybody for the cheerful
29:44
episode so far. But now we're getting on to
29:45
happier news. This is a really fun story
29:48
and it's born from Western Australia. Western
29:51
Australia is home to some of the very oldest
29:54
rocks that survive on the surface of the
29:56
Earth. Yeah, um, I've mentioned before, the
29:58
oldest fossils on Earth that are widely
30:00
accepted are found out in the Pilbara region,
30:02
date back about three and a half thousand
30:03
million years. This is actually rocks that
30:06
are a bit older than that. This is
30:09
feldspar crystals in
30:12
some old, old, old volcanic type
30:14
rocks called magmatic anorthosite.
30:18
Now, I'm not a geologist, I can't tell you
30:20
exactly what that is, but these are rocks
30:23
that on the surface of the Earth are very,
30:25
very rare. Feldspar is one of these minerals.
30:28
I'm led to understand that on the surface of
30:31
the Earth, it's very rare, but you find most
30:33
of the Earth's, uh, feldspar, those kind of
30:35
minerals that would form it deep in the
30:36
Earth's mantle. So we have very little of
30:38
this on the Earth's surface. By contrast,
30:41
there's a hell of a lot of feldspar on the
30:43
Moon, I think, particularly on the maria
30:45
there on the lunar seas.
30:48
Now, people like to study the
30:51
oldest rocks on the Earth because it gives us
30:52
a window into the planet's youth, into things
30:54
like when did the continents first start to
30:56
form? How did that process happen? You know,
30:59
how did we get plate tectonics getting
31:01
started on our, uh, young magmatic, uh,
31:03
Earth? How did all that happen? We've also
31:06
got this whole thing which has been a puzzle
31:08
for a very long time about the origin of the
31:10
Moon. So you've got the Earth and Moon flying
31:12
through space together. The Moon is
31:14
sufficiently close and tightly held by the,
31:16
uh, Earth. And in the past it was even closer
31:19
and more tightly held that it can't be an
31:21
object that was gravitationally captured from
31:23
elsewhere. That would be incredibly difficult
31:25
to happen. Um, from an orbital mechanics
31:28
point of view, which is my wheelhouse, that's
31:30
not something you could expect so the Moon
31:32
has to have formed with the Earth, uh,
31:35
which means that you'd expect them to look
31:37
the same, have the same composition. But the
31:40
Moon is depleted in the heavy elements that
31:42
are common near the Earth's core. And it's
31:44
enriched in the material that you'd find in
31:46
the Earth's mantle and the Earth's crust. But
31:49
the isotopic abundances, the things that give
31:52
you a very fine tuned position on where in
31:54
the protoplanetary disk the thing formed, the
31:57
Moon and the Earth are essentially identical.
31:59
So the bulk composition is different, but the
32:00
makeup of the different elements is the same.
32:03
So all these pieces of evidence point
32:06
to what is known as the Moon forming impact
32:09
theory, which has become really widely
32:10
established. A giant impact theory, the idea
32:13
that the Earth formed all in its lonesome
32:15
poor Earth, all alone. And then it made a
32:18
friend. It had a collision with an object
32:20
about the size of Mars, which people commonly
32:22
call Thea. And this collision was
32:25
pretty catastrophic. Um, certainly would have
32:28
been life ending for any life that had
32:30
already begun to develop on the Earth because
32:33
it tore the Earth asunder, It shattered the
32:35
Earth and spattered the mantle and the crust,
32:38
particularly into the space around the Earth.
32:40
The impact wasn't energetic enough to totally
32:43
disrupt our planet. So the Earth's core
32:44
stayed relatively intact. That's part
32:47
of the story. So what happened then was all
32:49
this material that had been splashed out,
32:51
which was primarily the mantle and the
32:54
crust, the light material, a lot of it
32:56
agglomerated in orbit around the Earth, uh,
32:58
to form the Moon at, uh, a distance just a
33:00
little bit further out than the Roche limit.
33:02
So the Roche limit, as a reminder, is the
33:04
closest distance you can take a solid object
33:07
to a planet before that planet's gravity
33:09
pulls it apart due to tidal forces. Yep,
33:11
Moon formed a little bit further out than
33:13
that initially, going around the Earth every
33:15
few hours while the Earth was spinning really
33:17
quickly. And over billions of years,
33:20
the tidal interaction between the Moon and
33:22
the Earth has caused the Moon to drift away,
33:24
exchanging angular momentum with the surface
33:27
of the Earth with the Earth's rotation, which
33:28
means our rotation has slowed until today we
33:31
get to a 24 hour, well, 23 hours,
33:33
56 minutes and 4 seconds rotation for the
33:36
Earth, technically, with the distant stars
33:39
and the Moon going round, you know, roughly
33:40
once a month, and it's still edging away a
33:42
little bit. We can measure that incidentally,
33:44
with the retroreflectors the Apollo
33:45
astronauts dropped on the surface of the
33:47
Moon, which is yet more evidence that the
33:49
Moon landings definitely happened. Not that I
33:51
think Anybody listening to this podcast will
33:53
question that they're not in that particular
33:55
conspiracy camp.
33:56
Andrew Dunkley: Although if I can just jump in there. There
33:58
was a post, uh, on Facebook I read this
34:01
morning, and it, uh, posed the question,
34:03
something you were told at school that proved
34:06
to be wrong. And someone's put the answer.
34:09
Moon landing.
34:10
Jonti Horner: Yes. Yeah, I mean,
34:13
I've seen all sorts of memes about that one.
34:16
One, um, that always sticks to my mind is
34:18
that of course the moon landing was faked,
34:19
but they got Stanley Kubrick to do it and he
34:21
was such a stickler for detail that he wanted
34:23
to film everything on location, you know,
34:26
um, but
34:29
anyway, we've got this very well established
34:32
story of the origin of the Earth Moon system
34:35
and how it all worked. And
34:37
all the pieces seem to fit. Yeah, there's a
34:39
little bit of tuning around the edges going
34:41
on. Whenever we get new information, we
34:43
refine the story, we get a better model of
34:45
what's happening. You sometimes get
34:47
additional parts of the story, like trying to
34:49
explain why the side of the Moon facing the
34:51
Earth and the side of the Moon facing away
34:53
from the Earth are so different. That's part
34:55
of the ongoing narrative of what happened in
34:58
the impact and what happened afterwards.
35:00
These new results are, uh, really nice
35:02
because they, uh, are essentially an
35:04
additional piece of supporting evidence for
35:07
this whole big splat type theory.
35:09
They're looking at these feldspar crystals in
35:12
these magmatic anorthosite rocks.
35:15
These are rocks that, ah, are so common on
35:17
the Moon that the Apollo astronauts brought
35:19
some back. So yet again, shrike one for we've
35:21
actually been there, um, on Earth,
35:24
they're very, very scarce. But what's really
35:26
nice is that the rocks that they've found in
35:28
wa with these crystals in, they've been able
35:31
to analyze the chemistry of them, and they're
35:33
essentially identical to the feldspar found
35:35
on the Moon.
35:35
Andrew Dunkley: Wow.
35:36
Jonti Horner: Really kind of spot on. A really good match.
35:39
And that's just a really
35:41
additional strong piece of evidence that
35:44
we're following the right narrative, that
35:46
we're on the right lines, that the Moon and
35:48
the Earth were formed in a giant collision.
35:50
Um, we've got evidence incidentally that
35:52
giant collisions were very much the norm in
35:54
the final parts of planet formation. And
35:56
there are arguments for every one of the
35:58
eight planets to suggest that they may have
36:00
fallen victim to at least one possibly more
36:03
giant collisions. Not all of those will
36:05
necessarily be borne out, but they were just
36:07
the norm rather than the exception. And the
36:09
Earth Moon system was a prime example. Now
36:12
Earth Moon 1 was probably the first giant
36:14
collision that was really scientifically
36:16
supported. Although you know people have been
36:18
suggesting a giant collision for Uranus to
36:20
explain its tiptoeveness for a very long
36:22
time. Just a natural part of the planet
36:25
formation process was probably the planet 9
36:27
that did that. Well that's part of where the
36:30
planet nine story comes in as well because it
36:33
is likely that there were planet mass objects
36:35
or bigger that formed in the outer solar
36:37
system that were scattered outwards. I had a
36:39
very dear friend of mine and good
36:41
collaborator visiting for the last couple of
36:42
weeks from Japan. That's um, Professor
36:45
Patrick Sophia Lukashka. Um, and Patrick was
36:47
telling us about his latest work which is
36:49
getting submitted to journal soon. Looking at
36:52
the structure of the Transept Union region.
36:55
So the Edgeworth Kuiper Belt, the scattered
36:57
disk, the detached objects, all these things
36:58
that are pristine pieces of evidence for
37:01
the early formation of the solar system and
37:03
how the planets moved and migrated. And what
37:06
he's finding that's really interesting is
37:08
that Neptune migrating outwards. The models
37:10
we currently have do a really good job of
37:12
explaining the solar system inside about 50
37:15
au. So the Edgeworth Kuiper Belt, the
37:17
scattered disk, but they do not fit and
37:20
do not match at all the objects that are
37:22
further out if you do not have additional
37:24
planets further out. So it's yet m more of
37:27
this building the narrative a bit like the
37:28
moon farming impact. We just keep finding
37:30
more and more evidence that
37:33
takes further observation. Now that's going
37:35
to be interesting. Obviously once Patrick's
37:37
work comes out I'd happily hop back on and
37:40
fill you all in on it because it is really
37:42
cool work. Um, and I think that
37:45
kind of stuff deserves more of a profile. I
37:47
will be a co author on those papers
37:48
incidentally, so I'm very excited about that.
37:50
Very good.
37:51
I'm coming back to this work. So looking at
37:52
these Felspar uh, crystals. Yes
37:55
there's another point that's just made as a
37:57
byline in this. And again not being a
38:00
geologist, I'm not fully across the why of
38:02
this but another of the results that comes
38:04
out of this study of the chemistry of the
38:05
feldspars and where they found them in these
38:08
um, what was it? The um,
38:11
magmatic anorthosite. And um,
38:13
a side result that's come out of this
38:15
suggests that we may have to slightly revisit
38:18
our clock and our understanding of when
38:21
the continents themselves began to form when
38:23
you first started getting continent
38:24
formation, which I think. And again
38:27
please write in if I'm summarizing this badly
38:30
but I think it's due to the nature of the
38:33
rocks that are extruded through the eruptions
38:36
from the mantle and the volcanism that goes
38:39
on, um, as the planet cools, as you get
38:41
different chemistry going on, you get a
38:43
fundamental change in the natural
38:45
material that is being extruded and
38:48
eventually get to a point when you can form
38:49
continental crusts essentially and the nuclei
38:52
of continents. Um, apologies if that's badly
38:55
explained, but like I said, it's not really
38:56
my wheelhouse there. But the side result
38:59
of this work is suggesting that that
39:01
continent construction process, the formation
39:03
of the first continents, didn't start until
39:06
about three and a half billion years ago. So
39:08
that's about a billion years after the Earth,
39:10
uh, formed, probably about a billion years
39:13
after the moon forming impact, which is
39:14
putting a clock on how long it took the Earth
39:17
to cool down enough to start that process.
39:19
But what I found really interesting, it
39:21
wasn't really mentioned in the article, is
39:23
tied back to what I said right at the start
39:25
of this bit. You have
39:27
this idea, you have this evidence from the
39:29
Pilbara region that the oldest fossils
39:32
on the Earth are three and a half billion
39:34
years old. You're now getting suggestions
39:37
here that the start of continent formation on
39:39
the Earth happened three and a half billion
39:40
years ago. Makes you wonder whether there's
39:43
correlation there, whether there's causation
39:45
there. In other words, life
39:48
became established well enough to give us
39:50
fossils at the earliest possible
39:52
opportunity it had. Now that's
39:56
very speculative at this point, but it's an
39:58
important datum when it comes to the search
40:00
for life elsewhere because the faster life
40:03
got started on Earth once the opportunity was
40:05
there, the easier that suggests it is for
40:07
life to get started. And therefore the more
40:10
confident we can be when we start looking for
40:13
life elsewhere, when we, when we do that. So
40:15
that's a nice little angle I think, to finish
40:17
on with this one, but it's a very cool story
40:19
and well worth following up for people who,
40:21
particularly those who are into the geology.
40:23
Yes.
40:23
Andrew Dunkley: And if you'd like to read about it, space.com
40:25
or you can go to the University of Western
40:27
Australia website. There's a, um, a really
40:30
good uh, article on that website about
40:33
the, the discoveries that have been made.
40:36
Uh, one final story. Jonti
40:39
and um, Fred and I have sort of
40:42
talked about this on and off for a
40:45
very long time. And that is, uh, you know,
40:47
what's going to happen to the universe? Uh,
40:49
is it going to continue to expand at an
40:52
accelerating rate and ultimately rip.
40:55
When I was growing up, uh, the opposite was
40:57
going to happen. There was going to be the
40:58
big Crush or the Big Crunch or the gab
41:01
gib, which is the opposite to Big Bang.
41:04
Um, now the,
41:08
the current thinking is that it was
41:09
accelerating, um, outward,
41:12
uh, and getting faster and faster.
41:15
Now we've got evidence that's starting to
41:18
suggest that the original
41:20
theory might actually be where we're
41:23
headed. This one is, um,
41:26
yeah, it's a bit of a tug of war between two
41:29
potential theories.
41:30
Jonti Horner: It is, and it's very much a great
41:32
illustration of how science works at the
41:34
frontier. It's very much a journey of
41:36
discovery that is a really complex interplay
41:39
of observation and theory. Um, astronomy is a
41:42
bit different to the other sciences in that
41:44
in physics and chemistry and biology, you can
41:46
do experiments in the lab, whereas in
41:48
astronomy everything's so far away you have
41:50
to observe. So we're a bit more Sherlock
41:52
Holmes than an experimentalist is.
41:55
He's a detective story gathering clues.
41:58
Now, there was a, uh, massive paradigm shift,
42:01
massive revolution back in the late 1990s
42:04
which led to the awarding of the Nobel Prize.
42:06
That went to a team including Brian Schmidt,
42:08
who is a, you know, famous researcher in
42:11
Australian circles, was briefly the VC of the
42:14
Australian National University. Seems to be
42:16
an all round good guy, but apparently doesn't
42:18
make the best wine on the planet. It's what
42:19
I've been told. Um, and sorry,
42:22
Brian, if you're listening, that's just total
42:24
hearsay. Uh, but there you go. But he's,
42:27
he's an absolutely stand up guy, um,
42:30
and got the Nobel Prize, which, you know,
42:32
doesn't happen to everybody.
42:34
Andrew Dunkley: No.
42:34
Jonti Horner: And that was all around observations of
42:37
distant supernovae right at the outer
42:40
edge of the universe. Now these
42:42
supernovae are one of the things that
42:44
astronomers use as a standard candle. So this
42:46
is how we build the distance ladder to the
42:48
distant universe. We have a number of
42:51
different techniques that allow you to
42:52
measure distance that work at different
42:54
scales. So if you want to get the distance to
42:56
the nearest stars, you use parallax, which is
42:59
Earth goes around the sun. We observe from
43:01
two sides of the Earth and we see the star
43:02
move against the background. And the bigger
43:04
the motion, the closer the star is. And you
43:07
can do this yourself. You can hold a finger
43:08
up in front of your face, close one eye and
43:11
look where the finger is against the
43:12
background, then open the other eye and look
43:13
at where it is. And by the shift you get an
43:16
idea of how far away it is. And I think, you
43:18
know, this is how cricketers and other
43:20
spots catch balls. Your
43:23
brain is Naturally doing this kind of
43:25
triangulation. Um, hopefully that won't be
43:27
working that well for the Aussies in the
43:29
coming Ashes match. That's going to start
43:30
fairly soon. Um, they're all getting a little
43:32
bit old and creaky. So I can speak from
43:35
personal experience. Depth perception is
43:37
challenging then. Um, but
43:40
that's the paddle axe method, and that gives
43:41
you the distance to the nearest starts. But
43:44
eventually, stars are far enough away that
43:47
that wobbling is not measurable
43:49
anymore. So we can't measure their distance
43:52
in that way. But fortunately, there's a class
43:54
of stars that are fairly rare but fairly
43:57
luminous called Cepheid variables. And this
43:59
was great work done, I think, by, um, Henry
44:02
Ever Till Levitt back in the early 1900s,
44:04
who identified by looking at the
44:07
Large Magellanic Cloud, that all the Cepheid
44:09
variables in the Large Magellanic Cloud,
44:12
which are all effectively the same distance
44:14
away, the brighter ones oscillated,
44:17
uh, with a different period than the slower
44:19
ones, and all the ones of the same brightness
44:21
oscillated with the same period. So what that
44:23
tells you is if you can measure the period
44:25
that these variable stars wibble, you can
44:28
infer their total brightness, you can
44:31
measure how bright they are in the sky and
44:33
therefore work out the distance. So that
44:34
gives you a standard candle. The
44:37
most distant leg of the standard candles, uh,
44:40
are supernova 1A, which are stars, uh,
44:42
reaching the end of their life and going
44:44
boom. And, um, there's always been this
44:45
suggestion that all Supernova 1A
44:48
reach about the same maximum brightness.
44:51
So if you can measure how bright a supernova
44:53
appears to you, you can measure its distance,
44:55
and it gives you that standard candle at
44:57
immense cosmological distances. The work
45:00
done in the late 1990s was looking at the
45:02
most distant supernova ever seen
45:06
to put a distance on those galaxies and
45:09
then measuring the redshift of those galaxies
45:11
to find out how fast they're moving away from
45:13
us. In other words, to m map how the
45:15
expansion of the universe changes with
45:17
distance. And what they found was hugely
45:20
surprising to everyone. Their results
45:21
indicated that rather than the expansion of
45:23
the universe slowing down as gravity starts
45:26
to pull back, the expansion of the universe
45:29
has actually been accelerating, getting
45:30
quicker and quicker, which is not what you'd
45:33
expect if you think gravity is the thing
45:34
that's winning. And, um, this was the
45:37
discovery that led to the birth of the idea
45:40
of dark energy, or, you know, the discovery
45:42
of dark energy, which is considered to be 68%
45:45
of everything in the universe. It's a really
45:46
big Contributor all of the evidence for that
45:49
came from this expansion of the universe
45:51
accelerating and getting quicker and quicker
45:53
as time goes on. Now, it's just a couple of
45:56
years ago that there were some new results
45:58
that came in that slightly throttled back on
46:00
that. They did a little bit of a
46:02
recalibration of that distance
46:05
supernova data, um, apparently
46:08
using baryonic acoustic oscillation
46:11
measurements. I'm not a cosmologist. I have
46:13
no clue what that is, to be honest, but
46:15
that's how they did this. And that led to the
46:18
conclusion that, yes, the acceleration
46:21
is there, but it's not as pronounced as we
46:23
think, and it should stop at some point and
46:24
then the universe should start decelerating,
46:26
should start slowing down again. Because it
46:29
turned out that they corrected for the data,
46:32
uh, that had been made in the original
46:33
discovery. They got essentially better
46:35
observations, better data that allowed them
46:37
to refine things. So that suggested that
46:39
instead of the acceleration increasing, the
46:42
acceleration was starting to ramp, um, down
46:43
and would eventually start decelerating. So
46:46
that started throwing things into doubt. The
46:49
new results have brought in an additional
46:51
thing where they are now realizing that the
46:54
brightness of the Supernova 1A
46:56
standard candles may not be as constant as
46:59
people think, that there's actually an edge
47:02
brightness relation where supernova
47:05
in the distant universe and supernova close
47:07
by will reach different maximum brightnesses.
47:11
And that means you then have to recalibrate
47:13
the distances to the things in the very
47:15
distant universe again, which changes
47:18
the lens on whether they
47:21
are accelerating more slowly or more quickly
47:23
than expected, and therefore changes the
47:25
outcome of whether the acceleration, whether
47:28
the expansion of the universe is accelerating
47:30
or slowing down. Now, it's
47:33
stressed in this that these, uh, new results
47:36
still have to be confirmed in that there
47:38
needs to be more data obtained to support
47:40
what their conclusions are. But if
47:43
what they've discovered here is correct, then
47:46
the team involved are arguing that this could
47:48
be the biggest paradigm shift in this area
47:50
for 27 years, since that discovery of dark
47:53
energy, since the discovery of the
47:55
accelerating expansion of the universe. And
47:57
they're even suggesting that the universe's
47:59
expansion may already be decelerating, so
48:02
it may no longer be accelerating. Um,
48:06
there are suggestions, therefore, that dark
48:08
energy is weakening, that the universe is
48:10
going to slow down and eventually turn
48:12
around. I should stress that this is so far
48:14
out of my wheelhouse that, uh, that's about
48:17
the level of the depth that I can go into it.
48:19
If you want to do a deep dive on this. We're
48:21
very fortunate up here in Queensland to have
48:23
one of the world's leading cosmologists at
48:24
the University of Queensland. Um, Professor
48:26
Tamara Davis, who now has the Order of
48:29
Australia Medal, um, oam. She's a
48:31
fabulous science communicator and she is one
48:33
of the world's real leading experts.
48:36
She's one of the leading lights in the Dark
48:37
Energy survey. So if you were ever in a
48:40
position to get somebody on as a guest to
48:42
talk through all this, because I know the
48:44
audience loves it, she will be an ideal
48:46
person if she was free. Tam's brilliant, but
48:48
in terms of building on this, I talk
48:51
a lot about Vera Rubin Observatory coming
48:53
online because I'm excited about the solar
48:55
system side of it. It's going to find more of
48:57
everything. Part of finding more of
48:59
everything, though, is that Vera Rubin will
49:01
discover and observe
49:04
somewhat more than 20,000 thousand
49:07
new supernovae in very distant galaxies,
49:10
um, over the next five years, allowing
49:13
more precise age and distance, um,
49:15
measurements that have ever been made before,
49:18
which should actually allow people to
49:21
work out whether what this team is finding
49:23
holds water, whether the original ideas
49:25
were right, what the story is.
49:28
So I think this is a very moving story and
49:30
we've certainly not reached the end of the
49:32
debate over the exact nature of the expansion
49:34
of the universe and by extension dark energy.
49:37
But this is pointing at the fact that there
49:40
is more to learn. And I guess this must be
49:42
how people feel when you start getting close
49:44
to those scientific paradigm shifts that are
49:47
huge, like when relativity and quantum
49:50
mechanics were developed in the early 1900s.
49:52
For a couple of decades before then, results
49:55
had not been quite what you expected. And
49:56
there was this growing feeling that there was
49:59
something more to come, but they weren't
50:00
quite there yet. Um, and this has that feel
50:03
that the next big discovery is just around
50:05
the line and we're starting to get stronger
50:06
and stronger evidence that there's something
50:09
really awesome to learn in the next few
50:10
years. Yeah, it's very, very exciting,
50:13
but also very much out of my comfort zone.
50:16
Andrew Dunkley: Yes, but it's also one of those topics that
50:19
people latch onto and we get so many
50:22
questions about. And I think we actually got
50:24
a question of this ilk for our next episode,
50:26
which is the Q and A episode. So, uh, we'll
50:29
be tackling that again. But, uh, yeah,
50:31
fascinating story. And if like to read all
50:34
about it, you can do that, uh, by looking up
50:36
the paper, uh, on the monthly notices of the
50:39
Royal Astronomical Society, uh,
50:42
and I think it's titled, uh, Strong
50:45
Progenitor Age Bias in Supernova
50:48
Cosmology. There you are. Um, hope you
50:51
wrote that down. Um, that's it. Thank you,
50:54
Jonti. Uh, entertaining and informative
50:57
as always.
50:59
Jonti Horner: It's an absolute pleasure. Thank you for
51:00
having me. And sorry for the runtiness. Um,
51:01
it's been a runty week, so I feel that we
51:03
should have at some point.
51:05
Andrew Dunkley: We'll get around to it. Uh, John D. Horner,
51:08
professor of astrophysics at the University
51:09
of Southern Queensland, joining us this week,
51:12
uh, while Fred Gallivant's around Edinburgh.
51:16
Uh, and don't forget, uh, oh, and,
51:18
um, Huw in the studio. We have to thank him.
51:21
He couldn't be with us today. He got himself
51:23
300th in the queue to have his, um, mortal
51:26
remains sent to Mars.
51:27
Jonti Horner: And.
51:28
Andrew Dunkley: And, uh, yeah, he's just, um, waiting for his
51:30
chance to pay the deposit. Who's going to
51:33
tell him? Uh, and from me, Andrew Dunkley.
51:35
Thanks for your company. We'll catch you on
51:37
the next episode of Space Nuts. Until then,
51:39
bye Bye.
51:41
Jonti Horner: You'll be listening to the Space Nuts
51:43
podcast, available at
51:46
Apple Podcasts, Spotify,
51:49
iHeartRadio or your favorite podcast
51:51
player. You can also stream on Twitter demand
51:53
at bytes. Com.
51:54
Andrew Dunkley: Um, this has been another quality podcast
51:57
production from bytes.
51:59
Jonti Horner: Com. Um.