Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / Challenger's Legacy, Cosmic Moons & the Mystery of Rapid Black Hole Growth

Transcript

Challenger's Legacy, Cosmic Moons & the Mystery of Rapid Black Hole Growth · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
Professor Fred Watson: Hi there.
0:00
Andrew Dunkley: Thanks for joining us on Space Nuts, where we
0:03
talk astronomy and space science, uh, twice
0:05
a week in fact, and I'm glad you could join
0:08
us yet again. Uh, today's
0:10
episode has some great, uh,
0:14
news, but also, uh, a bit of a sad
0:16
reflection. It's 40 years since
0:19
the Challenger space shuttle disaster.
0:22
Can you believe that? 40 years. Of course,
0:24
some of you listening to us won't
0:27
remember it because you're 40. Uh, but, uh,
0:30
for those of us who are a few years older,
0:32
uh, it is, um, a very, very strong
0:34
memory. We'll, uh, talk about that. On a
0:37
happier note, we will reveal the Australian
0:40
of the Year. I think most Australians will
0:42
know who that is. Uh, how do you
0:45
define a moon? That question has come up
0:47
because of a potential discovery and
0:50
they think they know why black holes are
0:53
getting bigger fast. We'll
0:56
talk about all of that on this episode of
0:58
Space Nuts.
0:59
Generic: 15 seconds. Guidance is internal.
1:02
10, 9. Ignition
1:05
sequence start.
1:06
Professor Fred Watson: Space Nuts.
1:07
Generic: 5, 4, 3. 2. 1. 2, 3, 4,
1:09
5, 5, 4, 3, 2, 1. Space
1:12
Nuts astronauts report it feels good.
1:16
Andrew Dunkley: Joining us as always, is his good self,
1:18
Professor Fred Watson, astronomer at large.
1:20
Hello, Fred.
1:21
Professor Fred Watson: Hello. It's good to be good.
1:23
Andrew Dunkley: It is good to be good. It's good to see you.
1:26
It's good to be in a cool room because it's
1:29
not cool in our part of the world at the
1:31
moment. We're right in the middle of a week
1:33
long, uh, run of 40 plus
1:36
Celsius temperatures. Uh,
1:38
we've, uh, broken our uh, record
1:41
in Dubbo for the hottest day in January
1:44
and that was
1:45
46.21 I think
1:48
we had, uh, on Monday on Australia
1:51
Day, which, um, yeah, it was dreadful.
1:54
I mean it was just horrific. Um, so,
1:57
yeah, it's, it's been a pretty rough week.
1:59
Um, my plants are suffering. There's nothing
2:01
I can do about it. And I, uh, think we're
2:04
going to lose a few. So unfortunately, that's
2:06
the way it goes. Um, I suppose that's what
2:09
happens when they plant plants in an
2:11
environment like this that um, don't come
2:13
from here. They struggle. But,
2:16
uh, yes, all, all is well with you?
2:19
Professor Fred Watson: Uh, yeah, our plants, uh, pretty well are all
2:22
natives, uh, in Marnie's garden. So they,
2:25
they don't seem to mind.
2:27
But we've got much more modest temperatures
2:29
than you have here on the coast.
2:31
Andrew Dunkley: Probably about 10 degrees cooler.
2:33
Professor Fred Watson: I imagine it's not quite that, but
2:36
not far off. Yeah, yeah, actually, no, it's
2:39
more like 20 at the moment. 20
2:41
degrees? Yeah, we're down at, um. But it's
2:44
forecast to be 29 today, so.
2:45
Andrew Dunkley: Yes, well, we're going to get to 41 I think
2:48
today, so I think we're already pushing
2:51
towards 30 as I speak. And it's only what,
2:54
9:30 in the morning local time. So,
2:57
um, we've got a lot to talk about, so we
2:59
better get stuck into it.
3:00
Uh, the first thing is, uh, something
3:03
that, um, I don't think anyone who
3:06
was around at the time will ever forget.
3:09
I'm talking about the Challenger space
3:12
shuttle launch, uh, in
3:14
1986. And this is
3:17
basically what happened.
3:19
Generic: T minus 15 seconds.
3:24
T minus 10, 9,
3:27
8, 7, 6. We
3:30
have main engine start. 4,
3:32
3, 2, 1.
3:35
And liftoff.
3:37
Andrew Dunkley: Liftoff.
3:37
Generic: Uh, of the 25th space shuttle mission and it
3:40
has cleared the tower.
3:46
Challenger
3:50
good roll program confirmed.
3:53
Challenger now heading downrange.
4:03
Engines beginning throttling down now at
4:06
94%. Normal throttles
4:08
for most of the flight. 104%.
4:13
Throttle down to 65% shortly.
4:19
Engines at 65%. Three engines running
4:22
normally. Three good fuel cells. Three good
4:24
APUs.
4:28
Velocity 2257ft per second.
4:30
Altitude 4.3 nautical miles downrange.
4:32
Distance 3 nautical
4:33
miles.
4:39
Engines throttling up. Three engines now at
4:41
104%. Challenger go at throttle up.
4:50
1 minute 15 seconds. Velocity 2900ft per
4:53
second. Altitude 9 nautical miles downrange.
4:55
Distance 7 nautical miles.
5:03
Professor Fred Watson: It.
5:18
M.
5:26
Generic: Flight controllers here looking very
5:28
carefully at the situation.
5:31
Obviously a major malfunction.
5:38
We have no downlink.
5:49
We have a report from the flight dynamics
5:51
officer that the vehicle has exploded. Flight
5:53
director confirms that we are looking at,
5:56
uh, checking with the recovery forces to see,
5:58
uh, what can be done at this point.
6:01
Andrew Dunkley: And there it is. That was the launch of
6:03
challenger in 1986, uh,
6:06
in real time. Uh, and
6:09
we heard the final words of, uh, the
6:12
commander, Dick Scobie, when he said, roger,
6:15
going with throttle up. And that was
6:18
basically where it all went horribly wrong.
6:20
Fred. Uh, the, um,
6:24
cause of the accident was ultimately
6:26
blamed on the O rings. The O rings
6:29
joined each section of the solid
6:32
rocket boosters and
6:35
there were several of them, but one of them
6:37
had a catastrophic failure and the, um,
6:40
uh, the vehicle exploded as a consequence of
6:43
that failure. And we all saw it,
6:46
we all watched, um,
6:49
was horrifying.
6:52
Professor Fred Watson: Uh, indeed it was. I remember it very well
6:53
too, of course. Um, so, yeah, it was
6:56
um, nothing to do with the throttling up.
6:58
That was just, that was just to get it going.
7:00
Yeah, and
7:04
they throttle back for the, um, maximum
7:06
dynamic pressure, uh, region. When you've
7:09
got the biggest aerodynamic forces, you
7:12
Throttle back for that and then throttle up
7:13
again. Um, and so it was
7:16
eventually determined that, uh,
7:19
what had happened was that the temperature on
7:21
one side of the shuttle, uh, it was a cold
7:24
morning, it was a winter morning, 28th of
7:26
January, 2 degrees, I think it was 2 degrees
7:29
above zero ambient when they launched. But
7:32
one of the one side of the
7:35
throttle, sorry, the shuttle and its boosters
7:37
were still at minus two. And uh, those
7:40
temperatures, um, those O
7:43
rings become effectively, uh, non
7:46
pliable. They, they don't, you know, they're
7:49
not flexible. Uh, and so that's what
7:51
allowed the fact that it was not behaving
7:54
properly allowed gas to escape from that
7:56
joint as exactly as you've said. There are
7:58
four sections to the shuttle booster, each
8:01
sealed by O rings. And it was the lower one,
8:04
um, where combustion was at its extreme.
8:07
Uh, it uh, meant the gases came through. And
8:10
in fact, uh, there is footage that shows
8:13
exactly that, uh, with these hot gases
8:15
playing on the main fuel tank, um,
8:19
the external fuel tank of the shuttle. So it
8:21
was, uh, very much their fate was
8:24
sealed even before launch, basically. And
8:27
there were people at the company who built
8:29
the boosters. Morton FIRE call who knew that.
8:32
And they were overridden in their
8:34
warnings that this was likely to be
8:36
dangerous.
8:37
Andrew Dunkley: They raised concerns a long time before this
8:40
happened. In fact, uh, they'd discovered
8:43
damage in the O rings from previous missions.
8:46
And even the night before
8:49
the launch they held a meeting to say,
8:52
we don't think you've got to scrub the
8:54
launch. It's not safe,
8:57
something dreadful could happen. And I
9:00
think, uh, the factor that
9:02
made the difference, as you said, was the
9:04
temperature that morning. Um, because
9:08
previous flights were warmer.
9:10
It was warmer, Yeah.
9:12
Professor Fred Watson: I think 12 degrees was the lowest they'd ever
9:14
launched at. And it was two that morning, as
9:17
you said. Um, and one of the
9:19
reasons for the
9:22
reluctance to scrub the mission may have
9:25
been the fact that we did have
9:28
this teacher, uh, on board,
9:31
Christina McAuliffe, that's her name, I
9:33
think. Um, she was, uh,
9:36
a schoolteacher, not an astronaut. Uh,
9:39
she'd engaged many, many schools
9:41
across the country. So
9:45
huge numbers of people were watching. And
9:47
NASA had done that purposely, I think, to
9:50
sort of inject some more interest into the
9:52
shuttle program. Because they'd had 25
9:54
successful launches and it was becoming
9:57
basically routine. Um, you know,
10:00
very. People were blase about it. Uh,
10:03
but just to also confirm
10:06
that there were a further 87 successful
10:08
shuttle launches after that. So the problems
10:11
were fixed and, uh, the lessons were learned.
10:14
Um, it was a tragedy, of course,
10:17
a human tragedy. With the loss of life.
10:19
Uh, I noticed something yesterday that
10:22
blew me away, Andrew. Um,
10:25
there are 17 astronauts
10:28
were lost, uh, in NASA
10:30
programs. The three, um,
10:33
Apollo 1 astronauts who died in
10:36
the fire on the ground, uh, of the Apollo 1
10:39
uh, capsule. That was on the
10:42
uh, 27th of January
10:45
1967. Yes, the uh,
10:48
Columbia disaster, uh, when
10:51
re. Um entry was um, basically turned
10:54
into a uh, you know, a disintegration because
10:57
of damage uh, to the, to the shuttle wing.
11:00
Andrew Dunkley: That wasn't it.
11:02
Professor Fred Watson: That's correct. That was on the 1st of
11:05
February 2003. So these
11:08
losses of life, we're all within a
11:11
week of each other in anniversary times.
11:13
It's quite amazing. So, yes, the
11:16
Challenger disaster, uh, 59
11:19
years before, uh, the day before we'd lost
11:22
the Apollo 1 crew. And uh,
11:26
um. It's a coincidence, but it's a spooky
11:28
one.
11:29
Andrew Dunkley: It is very spooky. I remember where I was
11:31
when the news broke. I just got in my car
11:34
and um, I naturally
11:37
had the radio on being someone who worked in
11:39
the industry. And uh, the news came on
11:42
as I was backing the car out and I just
11:45
stopped in my tracks and I just shook. I
11:48
couldn't believe it. Um,
11:50
and, and what really haunts me is that only a
11:53
week before I'd been talking to my
11:56
future sister in law who was still in high
11:58
school at the time. And she brought it up
12:00
with me about the space shuttle program. And
12:02
I said what worries me is something
12:05
horribly wrong is going to happen.
12:08
Yeah, uh, I, I think, I think they're
12:10
actually being too gung ho. Those. That's
12:13
what I said to her. And I couldn't believe
12:16
less. You know, about a week later this
12:19
happened.
12:19
Professor Fred Watson: Uh, well, you were right in, in a way that's
12:21
sort of what, what led to it.
12:23
Andrew Dunkley: Yeah, yeah. Uh, but the same thing,
12:26
uh, as you mentioned with the, the loss of
12:29
interest in the space shuttle program from
12:31
the public perspect, uh, happened with
12:34
Apollo like they supposed to, they were
12:36
supposed to have more missions but they just
12:38
went no, no one's interested anymore. So they
12:40
stopped at 17 and. Quite
12:43
right. And, and I, I suppose these
12:46
days space travel has just become
12:49
routine. There are missions going up and down
12:51
all the time we never hear about because
12:54
it's just it, it's so very regular
12:57
now. And, and when you bring in the private
12:59
sector on top of that there's launches every
13:01
other day. It's, it's just happening.
13:04
And was always going to go that way, I
13:06
suppose. Uh, but
13:08
um, you've got to spare a thought for
13:11
the pioneers that uh, sacrificed their lives
13:14
to make all this possible. Because without
13:16
them it just would never have got to the
13:18
point it is now. And I think
13:21
we've said it before. You go back to the
13:23
history of flight and we got to the moon in
13:26
less than 100 years of the first flight by
13:29
a human being in a, in a um, purpose
13:31
built uh, aircraft. It's just
13:34
extraordinary to think that we,
13:37
we could have leapt so far so fast. And I
13:40
suppose when you do that there is a price.
13:42
And this was one of the, one of the costs
13:44
of uh, of space travel and aeronautics and
13:48
yeah, it was very sad day and um, one I will
13:51
never forget. Red.
13:54
Uh, we will leave Challenger there um,
13:57
to some happier news and of course
14:00
uh, the other celebrated Australia
14:03
Day in this country. 26th of January
14:07
and every year we uh,
14:10
have the announcement of the Australian of
14:13
the Year. Now quite often it's a sports star.
14:16
That usually, usually happens. Uh, although
14:19
in recent years they've been focusing more on
14:21
the academic side of things or the medical
14:24
side of things. Which is, which is good. This
14:27
year though, uh, you must be really pleased.
14:29
It is an Australian astronaut,
14:33
uh, absolutely.
14:34
Professor Fred Watson: Delighted, yeah really thrilled about that.
14:36
Um, she's an astronaut
14:39
who uh, has been qualified under
14:41
ESA's Program Astronaut Program, uh, the
14:44
European Space Agency. She hasn't flown yet.
14:47
Uh, there's every chance that she will, that
14:48
she will fly to the space station, uh, and
14:52
fulfill a mission. Catherine bennelpegg
14:55
is her name. I discovered um, yesterday,
14:58
looking at dates yesterday obviously um, she
15:01
is one day short of 40 years younger
15:04
than me but her birthday is the day
15:06
after mine. So
15:09
that's a non coincidence. But um, not
15:12
only an astronaut, but she is also Director
15:15
of Space Technology at the Australian Space
15:17
Agency which was um, very much um,
15:20
close to my heart in the work that I did for
15:23
the government, the Australian Space Agency,
15:25
uh, a sister organization within the
15:27
Department of the Industry, Science and
15:28
Resources where I worked. So uh, a lot of
15:31
friends there. Um, and Catherine uh,
15:34
is uh, absolutely
15:37
well deserved recipient of the
15:39
annual Australian of the Year award and
15:41
she'll do great things with it. She wants to
15:44
be um, very much a STEM
15:46
ambassador as well for public ed,
15:49
for education, uh, for science, technology,
15:52
education. She'll do a great job. She's a
15:54
lovely person.
15:55
Andrew Dunkley: Yes, um, she comes across that way and
15:59
I think the interest in space science is
16:02
starting to really uh, grow from strength
16:05
to strength and uh, she will do
16:08
a wonderful job in that regard and
16:11
maybe inspire other Australians to follow in
16:13
her footsteps. And now that we have our own
16:16
space agency. We certainly want that, don't
16:18
we?
16:20
Professor Fred Watson: Very much so, yes. The Australian Space
16:22
Agency was formed in 2018.
16:24
It's um, still going strong.
16:27
A lot of its, uh, functions are regulatory.
16:30
It's all about regulating launches and things
16:32
of that sort, um, but also promoting
16:35
startups and things of that sort to encourage
16:38
the space industry here in Australia, which
16:40
was why it was set up in the first place.
16:42
Andrew Dunkley: Yeah.
16:42
Professor Fred Watson: Catherine. Catherine's a great, you know, a
16:44
great cheerleader for that. It's brilliant.
16:46
Andrew Dunkley: She's got a busy year ahead of her now
16:48
because her Australian of the Year duties
16:51
will be on top of what she has to do for her
16:53
regular gig. So she'll be doing a lot more
16:56
travel, a lot more speaking, a lot more
16:58
engagements. Uh, it, it's a big job when
17:01
you're named Australian of the Year, so I'm
17:03
told.
17:05
Professor Fred Watson: Well, you never know. Andrew. One day. One
17:08
day. Ah.
17:09
Andrew Dunkley: Uh, look, I'd be, I'd be lucky to
17:12
be named, you know, my street Member of
17:15
the year. Not a
17:18
big street either, but uh, no, good luck
17:20
to her. And uh, congratulations to Catherine
17:23
Bennell Pegg. This is Space
17:25
Nuts with Andrew Dunkley and Professor
17:28
Fred.
17:32
Generic: Okay, we've had a problem here. This is
17:34
Houston. Say again please.
17:35
Andrew Dunkley: Houston, we've had a problem.
17:36
Generic: We've had a main D bus. Roger made the
17:39
interval. Okay, standby 13. We're looking at
17:41
it.
17:42
Andrew Dunkley: Do you like that, Fred? We've got some new
17:44
links. I had a bit of time up my sleeve so
17:47
I um, created some.
17:48
Professor Fred Watson: New stuff that's a very appropriate one as
17:51
well.
17:51
Andrew Dunkley: Yes, I thought so too. Yeah.
17:53
Uh, now our next story is
17:56
about defining what is a moon.
17:59
This has come about after
18:02
a study been published, um, which
18:05
is a, um, peer reviewed paper
18:08
in the archive. Um,
18:11
it's looking at a really big gas giant, but
18:14
they think it's got a moon that could force
18:17
us to redefine what a moon is.
18:20
Is that the way it goes?
18:22
Professor Fred Watson: Well, yeah, because it's big. That's
18:24
right.
18:25
Andrew Dunkley: I got that impression.
18:27
Professor Fred Watson: Yeah. So, um, this is
18:30
uh, work, uh, that's been done,
18:33
uh, uh, actually led from the University of
18:35
Cambridge using uh, a uh, thing called
18:38
an interferometer, which is one of these
18:40
things that brings light waves together and
18:43
watches them cancel out. And by, um,
18:46
doing that carefully enough, you can uh,
18:49
learn a lot more than you otherwise could.
18:51
Uh, and there is an interferometer which is
18:53
called gravity. Uh, good name for it because,
18:56
uh, that's one of its tasks was to um,
18:59
kind of look at the. Look at the um,
19:01
gravitational forces around black holes,
19:03
which is done very successfully around the
19:05
black hole at the center of our galaxy. It's
19:07
on the Very Large Telescope in Chile. And
19:09
it's a way of, you will know and some
19:12
of your listeners, sorry, some of our
19:14
listeners will remember, uh, that the Very
19:16
Large telescope is actually 4 8.2 meter
19:20
uh, telescopes which can be used together,
19:22
uh, along with um, some auxiliary telescopes
19:25
as well. And that's uh, they're used together
19:29
in the science of
19:31
interferometry, which lets you uh,
19:33
look at um, objects in space
19:36
in very great detail. And in particular,
19:40
uh, the scientists have been watching the
19:42
orbit of a gas giant, uh,
19:46
uh, exoplanet, which
19:49
has the Lovely name of HD
19:50
206893B. It's
19:53
133 light years from our uh, solar system
19:56
as the crow flies. Um, but what they've done
19:58
is they've watched the motion of this gas
20:01
giant, uh, uh, as it
20:04
uh, orbits around its parent star, which is
20:06
HD 206893 itself. The
20:09
B refers at the end of that refers to the gas
20:12
giant planet itself. But what they've seen is
20:15
that the orbit of this giant planet
20:17
is wobbling slightly as it goes around
20:21
little, um, you know, deviations, uh, from
20:24
a perfect ellipse which are
20:27
interpreted uh, as being due
20:29
to a moon. And
20:32
by knowing the, knowing the mass of
20:35
the, or estimating the mass of the planet
20:38
itself, um, you can estimate the
20:41
mass of this moon and it's, it's
20:43
enormous. Uh, it's um, many
20:46
times the mass. If, uh, I remember rightly,
20:49
uh, something like nine times the mass of
20:51
Neptune, 40% of the mass of
20:54
Jupiter. Uh, and you
20:57
know, when you compare that with the moons in
20:59
our solar system, it's much, much heavier
21:01
than anything or much, much more massive
21:04
than anything we've got. Uh, so
21:07
that leads to the question, well,
21:10
you know, if you've got something that's nine
21:12
times the mass of Neptune, could you ever
21:14
call it a moon? Uh, but the normal definition
21:17
of a moon or satellite is
21:20
something that is in orbit around an object
21:22
that is in orbit around a star. In other
21:25
words, a planet. Um, so do we want to
21:28
bend that definition or are we just content
21:30
for this thing to be the most massive moon
21:33
known?
21:34
Andrew Dunkley: Well, where do you draw the line?
21:37
You know, if the definition is a satellite
21:40
orbiting at a, an object orbiting a
21:43
star, then that's. It shouldn't matter how
21:45
big it is, should it?
21:48
Professor Fred Watson: Uh, no, that's right, that would be my view,
21:50
uh, that um, you
21:53
keep the Basically keep the definition, uh,
21:56
as it stands, uh, what you do is you just
21:59
extend your range of uh,
22:04
expectancy in terms of
22:07
uh, the size of these objects. Um,
22:10
there's a, in fact there's a lovely comment.
22:13
There's several comments from the lead
22:14
author. Uh, I'm looking just to say where
22:17
we're looking. We're looking at Daily Galaxy
22:18
for this report, but it's a paper, uh, that's
22:21
been published I uh, think in Monthly
22:23
Notices, again, uh, one of the leading
22:25
journals anyway, um, and
22:28
the uh, you know, the, the
22:30
quotation from Quentin Crowell, who's one of
22:33
the authors, I think the lead author of this
22:36
paper. Um, uh, some
22:38
nice quotes. What we found is that
22:40
HD20683B doesn't just
22:43
follow a smooth orbit around its star. On top
22:46
of that motion, it shows a small but
22:47
measurable back and forth wobble. Wobble has
22:50
a period of nine months and a size comparable
22:53
to the Earth Moon distance. This kind of
22:55
signal is exactly what you'd expect if the
22:57
object were being tugged by an unseen
22:59
companion such as a large moon, making this
23:02
system a particularly intriguing
23:04
candidate for hosting an
23:07
exomoon. Um, and goes on
23:09
to say um, uh,
23:13
uh, this raises the question because of the
23:15
mass of this moon, this naturally raises the
23:17
question of whether such an object should
23:19
even be called a moon. These masses, the
23:21
distinction between a massive moon and a very
23:24
low mass companion becomes blurred.
23:27
However, there is currently no definition of
23:29
an exomoon and in practice astronomers
23:32
generally for generally refer to any object
23:35
orbiting a planet or substellar companion
23:38
as a moon. So that's the bottom line.
23:41
Um, uh, there are not many known and that's
23:44
because moons naturally are generally small
23:47
and so their effect on their, on
23:50
the planet around which they're orbiting is
23:53
too small to uh, discover.
23:56
Whereas uh, this thing is so big that its
23:59
signal is really quite, uh,
24:01
quite impressive. It's uh,
24:04
sufficient for this team to
24:07
give us the paper that we're talking about.
24:09
Just one final quote, uh, from Kral. Uh,
24:12
it's important to keep in mind that we're
24:15
likely only seeing the tip of the iceberg,
24:17
just as the first exoplanets discovered were
24:19
the most massive ones orbiting very close to
24:21
their stars simply because they were the
24:23
easiest to detect. The first exomoons we
24:26
identify are expected to be the most massive
24:29
and extreme examples. It's a really good
24:31
point.
24:31
Andrew Dunkley: And there it is. And, and yet again we
24:34
find in a potential new discovery
24:37
that it's not what
24:40
we would expect to be the norm. This, this is
24:43
Another thing that we may not have
24:46
anticipated.
24:48
Professor Fred Watson: Uh, that's. That's right. Um, so.
24:51
Yes. So, I mean, the point is well made.
24:54
Quentin's point is well made that the, uh,
24:58
the. The. That you're going to find the.
25:01
The real outliers first because they're the
25:03
easiest ones to find. Uh, but at, uh,
25:06
the same time, what you've said is true. Uh,
25:09
the outliers are sometimes so surprising that
25:11
they're difficult to believe. Uh, but we've
25:14
got a, um. Yeah, we've got an outlier here
25:16
that might well be the first of a new breed
25:18
of, uh. Or a whole new regime of
25:21
exomoon discoveries.
25:23
Andrew Dunkley: Yeah, I didn't even think about exomoons.
25:26
Like, we've discovered so many exoplanets
25:28
now, and we continue to do so, but we haven't
25:31
actually laid our eyes on an exomoon yet.
25:35
Professor Fred Watson: No. Um, and m. In fact, we've not laid our
25:37
eyes on most of the exoplanets. We've
25:39
inferred their presence, uh, by indirect
25:42
means. There are one or two, uh, that we can
25:45
observe directly. Uh, but when you think,
25:47
yes, moons are always going to be smaller
25:49
than their parent planets, um,
25:52
that means that, uh,
25:56
we're still pushing the limits of what is
25:58
technically possible to detect.
26:01
Andrew Dunkley: Could we maybe redefine this discovery
26:04
as, uh, like a dual planet?
26:07
Professor Fred Watson: So there is a definition of a dual planet,
26:10
um, what we call a binary planet,
26:13
uh, which is, uh. If you have
26:15
two objects, one orbiting the other,
26:18
if their center of gravity, or what we call
26:21
the barycenter, is outside the body of either
26:24
of them, then it's a binary planet
26:26
rather than a planet and a moon.
26:29
Uh, and in fact,
26:32
uh, Jupiter, sorry, Pluto and
26:35
its moon Charon fit that bill. Pluto, of
26:38
course, is a dwarf planet, but Pluto and
26:40
Charon are probably a binary dwarf planet for
26:42
that reason.
26:43
Andrew Dunkley: Okay. Interesting.
26:44
Professor Fred Watson: Yeah.
26:45
Andrew Dunkley: So, um, there'll be more work
26:49
to find out exactly what the situation
26:52
is here, because it's only suspicion at the
26:55
moment, isn't it?
26:56
Professor Fred Watson: That's right. There will be more observations
26:59
to confirm that, uh, uh,
27:02
the planet itself behaves in a way that is
27:04
consistent with this large
27:07
hypothesized moon. We haven't seen it
27:10
yet. In fact, we haven't seen the planet
27:12
either. But, uh, we can deduce
27:15
things from, uh, know, from the way the
27:17
orbits behave.
27:18
Andrew Dunkley: Yes, indeed. If you'd like to read about
27:20
that, the, uh, study's been published on the
27:22
archive, and it has been accepted for
27:24
publication in Astronomy and Astrophysics.
27:27
You can also read about it on the
27:29
dailygalaxy.com uh, website.
27:32
This is Space Nuts with Andrew Dunkley and
27:35
Professor Fred Watson.
27:41
Generic: Tranquility Base here. The Eagle has landed.
27:44
Professor Fred Watson: Space nets.
27:45
Andrew Dunkley: Speaking of, um, big planets with big
27:48
moons, what about big black holes,
27:51
uh, and the fact that they get big fast. We
27:54
have always been mystified by this
27:56
phenomenon. Uh, uh, have they
27:59
solved it, Fred?
28:01
Professor Fred Watson: Uh, certainly some work that looks as though
28:03
it's pointing in the right direction. Yeah,
28:05
this comes about really. And it's uh, an
28:08
issue that has uh, only arisen in the era of
28:10
the James Webb Space Telescope when, uh,
28:13
which has detected um,
28:15
the evidence for supermassive black
28:18
holes very, very early in the universe. Uh,
28:21
until the Webb came along, we all thought
28:23
that supermassive black holes evolved
28:26
over timescales comparable with the age of
28:28
the universe, that you started off with small
28:30
black holes. And as time went on, you
28:33
know, billions of years passing until we get
28:35
to the universe's current age of 13.8 billion
28:38
years, uh, that they gradually grew
28:41
bigger to form the supermassive black holes
28:44
that we see in today's universe. But when you
28:46
look further back, further out into space, as
28:48
the Webb has done, you're looking further
28:50
back in time. We're now seeing within a few
28:52
hundred million years of the Big Bang itself.
28:54
And we find these supermassive black holes
28:57
already there. Um, and that's the
29:00
puzzle. That's the conundrum. How did they
29:01
get so big so rapidly?
29:04
And the.
29:06
Andrew Dunkley: So, so they, they went to McDonald's. That's
29:09
what they did.
29:12
Professor Fred Watson: Uh, the McDonald's of the early universe.
29:14
Yes. There must be a, must be a name for
29:16
that.
29:17
Generic: Um.
29:19
Professor Fred Watson: Fast food. That's what it's not. It's fast
29:21
food. Yeah, I was going to work on drive
29:23
through somehow, but that doesn't scan quite
29:25
the same way as fast food does. It is
29:28
fast food. That's exactly. In fact, that sums
29:31
up the, the research paper by this team of
29:33
scientists who are actually based in Ireland,
29:37
uh, sums up their work very, very succinctly.
29:40
So the issue is, uh, that
29:43
uh, as we, as the, you know, so
29:46
what we've got is this observations, set
29:49
of observations tells us that black holes
29:52
got supermassive very quickly. And
29:55
that's a puzzle for the theoretical
29:58
astronomers who work out how
30:01
galaxies work, how galaxies form, how black
30:04
holes form, uh, and all of that
30:06
great stuff in the early universe. And
30:09
what um, has been the point
30:12
that they've struggled with is that if
30:15
a black hole starts eating
30:19
the surrounding material, which is how they
30:22
grow the gas and Dust that surrounds them.
30:25
If they start eating that too quickly,
30:28
in other words, quickly enough to grow into a
30:30
supermassive black hole very quickly. What
30:32
happens is um, the radiation
30:35
generated by this swirling mass of stuff
30:38
getting sucked in actually stops
30:41
the process. It quenches the process
30:44
of uh, accretion and the black
30:47
holes growing. That's the way the
30:50
theory has uh, appeared so far.
30:53
But what the Irish astronomers have done
30:57
is um, they've
30:59
looked at the sort of general
31:02
turbulence of the gas in the
31:05
early universe, uh, as a background
31:08
to the
31:11
feeding black hole. And it turns
31:14
out that if the universe
31:17
is um, a lot more
31:20
uh, chaotic, turbulent, very
31:23
violent motions in the background gas, if
31:26
you've got a black hole in an
31:28
environment like that, um, it
31:31
turns out that they can actually uh,
31:34
absorb huge amounts of gas and
31:37
so they can grow much faster than we
31:40
originally thought. Uh, so, um, one
31:43
of the authors, uh, of this paper,
31:46
uh, there's a quote here, um, this is
31:49
scitech Daily that uh, is carrying this
31:51
story. But uh, the, the research is in one of
31:54
the research papers, this is one of the
31:55
authors saying we found that the chaotic
31:58
conditions that existed in the early universe
32:01
triggered early smaller black holes
32:03
to grow into the supermarket. Massive black
32:05
holes we see later. Following a feeding
32:08
frenzy which devoured all the material
32:11
around them, we revealed using state of the
32:14
art computer simulations that the first
32:16
generation of black holes, those born just a
32:18
few hundred million years after the Big Bang,
32:20
grew incredibly fast into tens
32:23
of thousands of times the size of our Sun.
32:27
Uh, and another comment,
32:30
uh, from one of the other team members. This
32:32
breakthrough unlocks one of astronomy's big
32:34
puzzles, that being how black holes born in
32:37
early universe are observed by the James Webb
32:39
Space Telescope, uh, as observed by the James
32:42
Webb Space Telescope, managed to reach such
32:45
supermassive sizes so quickly. So
32:47
maybe that's the answer to the puzzle,
32:49
Andrew.
32:50
Andrew Dunkley: Yeah, they ate too much too fast.
32:54
Professor Fred Watson: That's right. Fast food.
32:56
Andrew Dunkley: And then they get indigestion and then they
32:58
have those, you know.
32:59
Professor Fred Watson: Well, I think that was the problem before,
33:01
uh, that you know, they got indigestion and
33:04
so they stopped the process. But what these,
33:07
these authors are saying is that if you put
33:09
them in a really turbulent um,
33:12
you know, field of gas, which
33:15
we think was in the early universe, then
33:18
things change. They don't get indigestion,
33:21
they just go for it.
33:22
Andrew Dunkley: They just eat and eat. They don't, don't
33:25
notice that they're full.
33:27
Professor Fred Watson: That's right.
33:27
Andrew Dunkley: And keep eating like a goldfish.
33:29
Professor Fred Watson: That's.
33:30
Andrew Dunkley: Goldfish have that problem. That's what they
33:32
say. Um, that's why they're so blobby
33:34
looking.
33:34
Professor Fred Watson: No, they don't want to stop eating.
33:36
Andrew Dunkley: No, they don't. No.
33:37
Professor Fred Watson: Apparently because they can't remember when
33:39
they started eating.
33:42
Andrew Dunkley: I don't believe that theory that goldfish
33:45
only have a three minute memory because I
33:47
used to keep goldfish and they knew who
33:50
fed them because they always reacted when you
33:52
went near the tank. Uh, the time to be. Time
33:55
for food. Time for food. They're like dogs,
33:57
except you can't take them for a walk. They
34:00
tend to buy.
34:01
Professor Fred Watson: Not yet.
34:04
Got to take their bowl with them as well. If
34:06
you try. Exactly.
34:08
Andrew Dunkley: You put them in a dog bowl.
34:10
Professor Fred Watson: Fill it with water.
34:11
Andrew Dunkley: No, uh, let's not go there. Uh, but that's a
34:13
fascinating story and, uh, another one that
34:16
will probably be subject to future analysis.
34:19
Uh, I imagine.
34:20
Professor Fred Watson: Yep, that's right.
34:21
Andrew Dunkley: If you'd like to read about it, as Fred said,
34:23
it's in scitechdaily.com or you can read the
34:26
entire paper, start to finish, if you're
34:28
having trouble falling asleep. And that's in
34:31
nature astronomy. Oh, dear. Um,
34:34
we're just about done, Fred. Thank you very
34:36
much.
34:36
Professor Fred Watson: Oh, a pleasure, Andrew. Always good to talk.
34:39
And, um, we'll see you next time.
34:41
Andrew Dunkley: We will. Professor Fred Watson, Astronomer at
34:43
large. Don't forget to visit us online in the
34:45
meantime@spacenutspodcast.com or
34:48
spacenuts IO you can have a
34:51
look around. You can visit the shop, you can
34:53
sign up for the daily news feed. Uh,
34:56
if you hit the supporter page. There are ways
34:58
to support us if you so desire. We will never
35:01
make you do it. It's voluntary. And plenty of
35:04
other things to see and do. And don't forget
35:06
our social media while you're at it, the
35:08
Space Nuts Facebook page or the
35:10
podcast group on, uh, Facebook.
35:13
They're very active. Always new members
35:15
joining there. We're on Instagram as well.
35:18
And I was going to say something else. Oh,
35:20
no, I can't remember. Anyway, um, that's just
35:23
about it. Um, also thanks to Huw in the
35:25
studio who couldn't be with us today. He's,
35:27
um, gone out to uh, the back to uh, to
35:30
brood for not being named Australian of the
35:33
Year. And from me, Andrew Dunkley. Thanks for
35:35
your company. See you on the next episode of
35:37
SpaceNuts. Bye bye.
35:40
You've been listening to the Space Nuts
35:42
podcast available at
35:45
Apple Podcasts, Spotify,
35:47
iHeartRadio or your favorite podcast
35:50
player. You can also stream on
35:52
demand@bytes.com. this has been another
35:55
quality podcast production from
35:57
bytes.um.com.