Latest / Space Nuts: Astronomy Insights & Cosmic Discoveries / #404: Terraforming Trials & Titan's Tantalizing Truths: Venusian Visions and Microbial Mysteries

Transcript

#404: Terraforming Trials & Titan's Tantalizing Truths: Venusian Visions and Microbial Mysteries · Space Nuts: Astronomy Insights & Cosmic Discoveries

0:00
By there, Andrew Dunkley here, Thanks for joining us on Space Nuts Q
0:04
and A. And on this episode, we've got a few things we need
0:08
to talk about terraforming for starters, we get questions about terraforming fairly regularly,
0:15
but we've got a new one. We've also got a question about a proto
0:18
star. Fred loved the name of this L one five seven. We'll see
0:24
if we can answer that one. We've got a question about the enjoyment of
0:28
science fiction? Are there limits to what you can do that will make or
0:33
break it? And a couple of our younger listeners have chimed in with questions
0:38
as well. We'll deal with all of that on this episode of Space Nuts
0:44
fifteen. In Channel ten nine ignition Sigunch Space Nuts ni Urn three two Space
0:57
notes as when as we bought it, Neils good and with me again is
1:00
Professor freed Wardson, Astronomer at Large. Hello, Fred, Hi Andrew,
1:04
looking forward to a few Q and a's. Yes, we've got quite a
1:10
bit to get through us. A couple of these will be pretty quick because
1:14
one of the questions, which is almost ironic, asks us exactly about something
1:22
we spoke about last week in episode four oh one, So we'll be able
1:25
to make a reference to that. But let's begin well, actually, let's
1:30
deal with that straight away. A young listener named Oliver, eleven years old
1:36
from Queensland has sent in a question and said, I was just wondering if
1:41
there was any chance that Titan could have micro organisms, and well, up
1:48
until recently we might have said yes, and I think the chance still exists,
1:53
but some recent data has been put together suggests Titan probably not as life
2:00
worthy as we once thought. Free that's right. So the bottom line from
2:06
our discussion last week was that the calculations that have been made by some astrobiologists
2:13
demonstrate that the water that filters down through the icy surface of Titan won't contain
2:21
enough of the carbon containing material that we know is on the surface of Titan
2:27
to make any difference to the ocean underneath. In fact, it was one
2:30
elephant mass per year, was it that was filtering down seven seven point five
2:37
tons? And that's a tiny amount when you compare it with a water reservoir
2:43
that towns. I believe we said twelve times the amount of water as the
2:46
assertions have so people are a bit depressed about that. I don't think I
2:52
mentioned in the program. I'm more optimistic because there is a possibility that there
2:57
might be microorganisms that don't use water, they're working fluid, but use and
3:02
methane as they're working fluid, and they will be very different from what we
3:06
know on Earth, but micro organisms nevertheless, so I think there's still a
3:09
possibility. Andrew, I'm not as pessimistic as maybe the authors of this article
3:14
were. Yes, So there you go, Oliver. The new data which
3:20
is based on modeling, so they don't have absolute proof, but it does
3:24
suggest that if certain things happen the way we think they did, Titan's less
3:30
likely to have life as we know it, but it might have other forms
3:34
of life. But I wouldn't write it off completely. But it also kind
3:38
of puts a bit of tips water on the other ice moons having life as
3:45
well, because they're less likely than Titan apparently to harbor life. So,
3:50
Oliver, thanks for the question, but if you go back to episode four
3:53
oh one, there's a much broader explanation of the situation you've asked us about.
4:00
Next question comes from Dan Hi, Andrew and Fred. I know a
4:04
few listeners have touched on this before, but i'd like to go a little
4:08
further on the terraforming thing, if I may, what would happen if we
4:13
were to place a huge megastructure at Venus's l one point, something like a
4:19
vast solar panel that blocked all the light from the Sun. How long would
4:24
it take Venus to cool down? And would that eventually lead to the runaway
4:29
greenhouse effect collapsing? It comes from Dan in California. I've got a nickname
4:36
for Dan in California. I'm going to call him Cala Dan, which is
4:41
one of the planets in a sci fi show that I've watched recently. Couldn't
4:46
help usself. There you go, and yes, So this touch is on
4:54
things we were talking about last week as well, because we were talking about
4:57
flotilla's of tiny spacecraft to reduce the radiation from the Sun on Earth, and
5:03
the idea was to do exactly as Dan suggests, put these flotillas of spacecraft
5:10
at the l one point between Earth and the Sun. So if you did
5:14
the same thing with Venus, it turns out that a solid lump of something
5:19
like a big sunshade, even if you could build something which would have to
5:23
be the diameter of Venus to work at all, that will be unstable.
5:29
It's not something that would probably stay intact. The gravitational forces might well break
5:33
it up. So you're better off starting off with small things rather than big
5:38
things. Dan's questions not about that though. Really it's about if you did
5:44
switch off the Sun, as far as Venus is concerned, how long does
5:46
it take to come back to something that we might recognize as a planet like
5:51
Earth? And I honestly don't know the answer to that. But my guess
5:55
is we are talking about geological timescales. We're talking about millions of years rather
6:00
than a fortnite or something like that. Just because that sudden loss of energy
6:06
would certainly transform the climate. It would shock the climate into a change.
6:15
But how long it might take for the change to take place, I don't
6:17
know. Just thinking slightly laterally though the thinking, I believe, as far
6:23
as you know, a kind of quasi related event on Earth's history, which
6:29
is the chick Slab impact sixty six million years ago. I think scientists who
6:35
look at that so yes, that thing ejected huge amounts of dust in the
6:40
atmosphere which blocked off the Sun. And I think it wasn't a fortnite but
6:45
I think the lengths of times for things to recover were measured in you know,
6:53
in decades rather than millions of years. But with Earth, what you're
6:58
talking about is a temporary blanket of the Sun, which is all the dust
7:02
in the atmosphere that eventually falls out and the Sun comes back to its original
7:08
brilliance, the atmosphere regains its original transparency, and so you're returning to the
7:13
status quo, whereas with Venus you're fundamentally changing everything. If you leave that
7:17
shut some shade in place, or equivalently, fill the atmosphere with dust,
7:23
that might have other consequences that because dust retains heat. So I think it's
7:27
going to take a lot longer. Yeah, Indeed, we've talked This was
7:32
quite a whilid and go we talked about that. I mean, Venus is
7:35
an example of a planet that may one at one time and it's past been
7:42
earth like, as was Mars. And so we've got three planets that at
7:46
one stage during the life of the Solar System were Earth like. I had
7:54
more what we would consider normal terrain and normal conditions, one of a better
8:00
work. Yeah, and sometime in its past the Earth was more tyson like
8:05
because there was the snowball Earth era when everything was frozen. So yes,
8:11
it's gone through various climatic changes and events. Fortunately it's landed up where it
8:18
is at the moment. In terms of the Earth, you know, ambient
8:22
temperature fifteen degrees celsius on our ridge and rising, yeah, rising, yes,
8:28
right, all right, Kelly, Dan, thank you so much for
8:31
your question. I always like to get those kinds of questions and dice them
8:35
up. But yeah, probably not feasible in terms of building the structure and
8:39
time frames would be rather extensive, and I'm probably understating that. From Dan
8:46
in California to Dan in Brisbane who wants to talk about a proto star for
8:52
red Hello to stand from Brisbane. If you do a Google search on proto
8:58
star L one five two seven, you'll see amazing James Webspace telescope image of
9:07
a accretion disc with two cones of material being ejected above and below the accretion
9:13
disc. Now, I believe this was the same situation is what happened to
9:18
our soul system when it was forming. But this protostar is one hundred thousand
9:22
years old, where our four point six billion years. So I'm wondering did
9:30
similar clouds of material form above and below the accretion disc plane. If so,
9:37
what happened to him after four point six billion years. I believe that
9:41
there's two forces of pressure coming from our sun. One is the photonic pressure,
9:46
which I think would be spherical, and the other one is the solar
9:50
wind, which probably varies over time, but I think bridge it would probably
9:54
be spherical as well. So I'd like to know how does the pressure,
9:58
say on on clouds of gas compare from the say, the solar wind and
10:03
the photonic pressure. And also what has happened to this cloud of material above
10:09
and below the plane of our solar system? Is there any remnant of it
10:15
left? Okay, thank you, Dan. A lot of information required to
10:20
answer that one. I did look up the website that he referred to,
10:24
the NASA website with that image of L one five two seven. I can
10:28
see what he's saying. I think we did talk about something like this recently
10:31
with the hourglass image that is created by that effect. Yeah, what,
10:41
well, it's yours s bread passing the ball. How do you answer this
10:46
one? So Done's you know, Done's conjectures are right, It's actually not
10:50
really an accretion disc. It's a protoplanetary disk that is in orbits around the
10:56
star itself, although as the caption that NASA provides for that Web telescope images
11:05
suggests, the cloud of material is actually feeding basically the nebulating nebula within which
11:15
this star has been born is feeding the growth of that protostar. So it's
11:22
a process that probably you know, includes various examples of stellar burps, if
11:31
I can put it that way, what you'd call, in a more formal
11:33
sense, sporadic ejections, where material is actually ejected from the star as it's
11:39
forming, And indeed there's evidence for several past stellar ejections in the web telescope
11:48
image. It's really it's a really extraordinary image, and thanks to Dan for
11:56
drawing our attention to it. But to bring it more up to date.
12:01
So I so long time as I've looked at these, But my understanding,
12:07
if I remember correctly from my time when he used to study cellar evolution,
12:11
is that all sunlight stars go through what's called a t Tory phase. Now
12:18
t Tory is basically another type of star. I'm just going to google that
12:26
as well, just to get my bearings correct with what I'm talking about.
12:31
I spent that. In fact, I think I have a paper back in
12:33
my long ago history where I was talking about T. Tory stars because so
12:39
I worked on them with a colleague on an instrument I just built. So
12:45
T Tory stars are a class of variable stars that are less than about ten
12:48
million years old. They're named after the prototype T. Tory, a young
12:52
star in the Tourist star formation region. They're found near molecular clouds and identified
12:58
by the optical variability and chromospheric lines. So they are basically sun like stars
13:05
that have not yet become sunlight, typically less than three times the mass of
13:11
the Sun. And what they do is they basically emit winds. The sorts
13:20
of winds that they blow are like the solar wind, much much stronger and
13:26
with much more energy you know, associated with them. So Tee Tourist stars
13:35
are effectively how a newborn star in a nevula blows away the residual gas,
13:43
gets rid of all this stuff that has formed its cocoon for a few,
13:48
perhaps tens or hundreds of millions of years. So they are, you know,
13:54
they're basically embedded in these gas clouds, but they blow out the wind,
14:01
which I think has down surmises are probably isotropic. I mean in all
14:07
directions, it's very clear symmetrical. So check out t Tourist Stars, Dan,
14:13
and you'll find that that might be the mechanism by which the residual gas
14:20
and dust is blown away. And so that an object like the Sun who's
14:26
lost already lost its siblings. The son would have been born with other stars
14:30
in the same dust cloud. And we know we can't identify what those stars
14:35
are. They won't be far away, and I'm sure it will happen one
14:39
day that stars with identical chemic called composition to the Sun will be discovered.
14:45
But you know that that means that because of the te Tory phenomenon, we've
14:50
lost all those remnants of the cloud, which is so obvious in the picture
14:54
of L one five two seven. Okay, there you Dan, if you
14:58
do it, so it for TEA Tory. It's tea single letter and Tory
15:05
t A U R I T Tory Star if you want to read up on
15:09
it. And thanks for the question. Is a really good one. This
15:13
is space Nuts Andrew Dunkley here with Professor Fred Watson. Okay, we check
15:20
your space nuts. Let's go to another question, and this one comes from
15:28
Star. That's so we're talking about a proto Star. Now we've got a
15:33
question from Star. I just wanted to start off by saying, thank you
15:37
so much for this amazing weekly podcast twice a week now. I always look
15:43
forward to it every Thursday, and your episodes helped me get through my astrochemistry
15:46
homework. Oh okay, good. I hope you didn't get your answers wrong
15:50
based on what we've said, I was wondering, when it comes to sci
15:54
fi, does your enjoyment of it depend upon how scientifically accurate it is,
16:00
where applicable or does it not matter? Also, if you have a favorite
16:04
sci fi series, book, movie, et cetera, I would love to
16:07
hear about it from Star. My enjoyment of sci fi is not limited to
16:15
anything. I will take every story on its merits, whether it's feasible or
16:19
not. I suppose one of my favorite sci fi movies would have to in
16:23
recent times be The Martian, which did actually base a lot of its storylines
16:30
on feasibility. They did stretch the envelope a bit, though, didn't They
16:34
fread a couple of times there with certain things, But they basically went with
16:41
a this could be possible scenario. But then I look at a movie like
16:47
Passengers, which is absolutely and utterly not feasible because you're basically cryogenically freezing people
16:55
and stopping their lives so that they can travel ninety years to another world and
16:59
then suddenly start their lives again, so they're ninety years older without getting any
17:03
older. And a lot of things in that film were just, you know,
17:08
they were stretching it beyond reasonable possibility in terms of the story. But
17:15
a great story nonetheless, and I really enjoyed it. And as far as
17:18
my favorite, my favorite sci fi story of all time, I'd have to
17:23
say it's Dune. I think Dune is probably one of the best sci fis
17:30
ever written, but there are so many it's probably unfair just to name one.
17:36
I mean, Isaac Asimov's Nemesis is brilliant, Kitchhiker's Guide to the Galaxy
17:44
probably one of the greatest of all time. The list goes on. There's
17:48
three that I can think of, Parallax, the Trannian Enigma, the Hitler
17:53
Paradox. They're all really good too. They're familiar sounding time a bit of
18:00
an unknown author. They're black great idea is just not a great execution,
18:07
Fred would you're not so much into sci fi as I am? Are here?
18:12
No, I'm not, definitely, and that comes from you know the
18:18
real thing. Well, I don't know that. It's that I used to
18:22
read the huge amounts of sci fi when I was just a lad, but
18:26
these days there seems to be far more to do, and so it's not
18:30
so not so much. But just picking up on what you said about passengers,
18:33
was it with that idea of suspended animation that in my experience goes back
18:41
to nineteen fifty five when Frank Hampson, who was the author of Dan Dayre
18:45
in the Eagle comic in Britain, actually put his put the whole crew into
18:51
suspended animation for about ten years so they could get to the solar system of
18:56
Loss with its two warring and it's cryptos and fantos. That's, for me,
19:03
was the stuff of why I became a scientist actually because I was totally
19:08
immersed in all that stuff back in the day, I have to say though,
19:14
And in fact, actually Frank Hampson, who was a genius artist as
19:18
well as a great educator and a great feminist as well, back in the
19:22
day, he had a character called Professor Jocelyn Peabody, and she was the
19:26
one who explained all the science, and so he put, you know,
19:29
the scientific explanations for what was going on in the in the mouth of a
19:33
woman, which was very unusual back at that time, but fantastic stuff,
19:37
way ahead of his time. But maybe it was that, maybe it was
19:45
the effect of my old time favorite movie two thousand and one, A Space
19:48
Odyssey, where you're where, you're where, you are actually keeping within the
19:56
bounds of scientific reality. That to me, he's an added if a science
20:03
fiction story keeps the physics right and the biology right, then it strikes a
20:07
chord with me compared with the ones that don't, and they're just annoying to
20:15
a scientist. Gravity comes to mind. Gravity was just way beyond the realms
20:22
of Yeah, it was was good in the sense that the the the basic
20:27
premise of a kind of Keshler syndrome thing was was good. But the idea
20:33
of being able to walk from one space space station to another with your pressure
20:37
suit on, that's just not on. And I mean the other one,
20:42
Interstellar, was lump it a bit over the top in that regard in stretching
20:48
the relativistic ideas. The one I liked, I've forgotten. We've talked about
20:53
it recently. What was the one called that had an interpreter working out how
20:59
to communicate with arrival. Yeah, magical movie. I like that one because
21:06
because there was so much that could be real in it, rather than you
21:10
know, being scientifically fictitious. That is, assuming that giant squid like creatures
21:15
did come to you've got to have that to start with. But that's the
21:19
point is you can't eliminate that scientifically because they might well be there, which
21:23
is very I don't know. That's the thing about aliens. You're never going
21:26
to be able to prove that they're not there. That's right. You can
21:30
prove they're there if you find well, but you can't ever prove they're not.
21:34
So you started something there start so. But the truth for me is
21:40
it doesn't matter whether there's a reality potential in it or it's just gone way
21:45
to the extreme. Yeah. I love the ones that are based on real
21:48
science. But Hitchhiker's Guide to the Galaxy, which is based on nothing but
21:52
a man's incredible imagination, just who nails it for me? It just does.
21:57
Thanks for the question. That was really good. Quick one for Fred
22:00
to finish from nine year old Ted, whose father has sent the question in
22:06
on his behalf Joe, why can I sometimes see the moon during the day
22:11
in the UK and does that mean there isn't a moon in the sky on
22:15
the other side of the Earth? Thanks Joe and Ted. The reason you
22:18
can sometimes see the UK in the sky is because the pollution is buying a
22:22
way briefly, the moon in the UK sky, Yeah, that's right,
22:26
or the cloud or the cloud. Well, it's true, that's absolutely true.
22:30
The fact is you can see the moon during the day anywhere it's not
22:34
you know, because the moon as it goes around the Earth is very often
22:40
above the horizon at the same time as the Sun is, and its phases
22:42
are different. What you tend not to see is a full moon during the
22:48
day because that tends to be all night long. You might see it at
22:52
dusk and dawn, but you won't see it in the full moon in the
22:55
middle of the day, whereas you can easily see half moons in the middle
22:57
of the day and all that doesn't matter where you are UK, North Pole,
23:03
South Pool, Australia, anywhere. But you're right, if you see
23:07
the moon in the day during the UK's daytime, you won't see the moon
23:12
in the sky in Australia because we're basically on the other side of the planet,
23:17
almost exact opposites. Yeah, that's right, we're almost the exact opposite,
23:22
so that's why. Yeah, there are times though, because of the
23:26
positioning and the distance, you can see the Moon from a great many places
23:30
around the world at the same time. I've sometimes been watching live golf from
23:36
the United States and they'll have an image of the Moon and I'll be going
23:40
in. I can't see that too, and you know, I'm thousands and
23:42
thousands of kilometers away. But it's all a matter of the angular perspective,
23:47
isn't it. Yeah, it's pretty easy. Actually, anywhere on the same
23:51
hemisphere that's facing the Moon, we'll see the moon. So that's half the
23:56
Earth, yes, you know, so it does include. Yeah, the
24:00
Pacific Ocean's big, separating Australia in the United States, but they can be
24:04
simultaneously in the same hemisphere pointing towards the Moon, so you see them there
24:11
you go ted. Hopefully that answers your question, and keep on gazing at
24:15
the sky you just never see. It's always fun up there. Fred.
24:21
That brings us to the end. And if you do have a question for
24:23
us, please go to our website and send it to us on the AMA
24:27
tab or the little button on the right that says send us your questions.
24:32
We'd love to hear from you, whether it's in text form or audio form.
24:36
And don't forget to tell us who you are and where you're from,
24:37
and don't forget to subscribe you for your YouTube follower and have a look around
24:41
on the website. Some great sci fi books on there, and some great
24:45
science books as well, more credibility. Thank you, Fred, a pleasure
24:52
as always, and for me too, Andrew, thank you for putting up
24:56
with my rumblings. And we'll speak again soon. We will, indeed,
24:59
and they're not ramblings by any means. Fred Watson, astronomer at large part
25:03
of the team here at Space Nuts. And thanks to you in the studio
25:07
for being just a nice guy. Oh I said something nice And from me
25:12
Andrew Dunfrey, thanks for your company. Looking forward to catching up with you
25:15
again later this week on the next episode of Space Nuts. Bye Byepnuts.
25:22
You'll be listening to the Space Nuts podcast available at Apple Podcasts, Spotify,
25:30
iHeartRadio, or your favorite podcast player. You can also stream on demand at
25:34
bites dot com. This has been another quantity podcast production from nights dot com.