Heidi Campo: Welcome back to another Q and A session of
Space Nuts. I'm your host for this
American summer, an Australian winter,
Heidi Campo. And joining us today to
answer all of your questions is Professor Fred
Watson, astronomer at large.
Generic: 15 seconds. Guidance is internal.
10, 9. Ignition
sequence start. Space nets 5, 4,
3, 2, 1. 2, 3, 4, 5, 5,
4, 3, 2', 1. Space nuts
astronauts report it feels.
Heidi Campo: Fred, how are you doing?
Professor Fred Watson: Oh, pretty well, thanks Heidi. Nearly as well as
I was the last time I saw you.
Heidi Campo: Oh, inside jokes. For those of you regular
listeners, you know what's going on.
Professor Fred Watson: Yeah. Because you were
a bit under the weather before.
Heidi Campo: I, I am. So if you guys hear my voice sounds a
little bit scratchy, I apologize. I was doing some
traveling recently and I was probably picked up a
little germ at the airport. But that's I, I,
I'll be okay. I think I'll survive this time.
Professor Fred Watson: Hopefully.
Heidi Campo: Hopefully. Yeah, I don't know. I guess you never know. Could
be, could be. didn't like you think
about those crazy cases where it's like didn't Bob, Bob
Marley died from skin cancer and it's like, I guess you really never know.
Professor Fred Watson: That's true.
Heidi Campo: Well, hey, here's something that hopefully you can
answer for us, Fred.
Rennie from S.A. sunny West
Hills, CA asks
theoretically, if an observer
scientist outside our universe was able to
look into our universe, would that
observers re research on light
speed and other phenomenon match our
scientists findings?
Professor Fred Watson: It's a great question, Rennie. Rennie's one
of our regular questioners and always asks the
provocative ones. I like it very much
so.
Professor Fred Watson: We'Ve got to envisage an observer that's in
some other universe where the light
speed and other, you know, other
fundamental quantities, speed
of light, mass of the electron, things like that, they might be
quite different. so you would
have to basically
think outside the box. We're talking now about the
biggest boxes that could exist. If we're talking about
separate universes, you'd have to
look into our universe and use yardsticks that
were basically part and parcel of
our universe in order to measure those
fundamental quantities. So
you'd need to have a way of determining distance,
and that way you could perhaps use
a way of determining time to determine the
speed of light. you might well be able to
determine that the speed of light in our universe was different
from the speed of light in your universe, which will be a very
interesting property. and it's actually
one of the reasons why People speculate,
Heidi, that, there might be other universes. The
fact that those physical parameters in our own
universe are so well suited
to, the formation of stars,
galaxies, planets,
stability that, would allow
molecules to be created that could eventually
turn into living organisms. One of the reasons
astronomers think there might be other universes is
because those properties of our own universe
are so well tuned to life that maybe there are
other universes where that is not the case.
And so if you were standing in one of those universes and looking back
at our own, you might well say, well, that's
ridiculous. The speed of light, there's only 300,000 kilometers
per second. It's much faster than that here.
So, you know, you could be looking at different parameters. So I think,
Rennie, it's an interesting thought experiment
and, thank you very much for the question.
Heidi Campo: It's very, interstellar when he goes into the
dimension where they're looking through a different
plane.
Our next question is from Dean, and
Dean says, I believe you all
had mentioned previously that in a,
protoplanetary disk, heavier
elements reside closer to the star,
which is the reason the interior planets of our
system are, quote, rocky. The
protostar is too hot for volatile
materials to become solid, and the solar
wind blows the lighter elements away. My
question was Earth in
a belt of protoplanetary disk
where liquid or water orbited? Could such
a belt exist in protoplanetary disk?
Professor Fred Watson: yeah. It is another great
question. And I suppose what Dean is
saying is, is there
a Goldilocks zone in the protoplanetary disk?
because the protoplanetary disk is
where the planets were formed. and
yes, the temperature of material in that disk
will vary. It'll be much hotter near the star itself
and much colder outside. And
we do see, just in the way the
planets of our solar system are distributed, with the four rocky
ones internally and then the four,
gaseous ones and icy ones further out,
we see that effect of,
the Goldilocks zone. So Mars
sits just within the sun's
ice. what's it called? The ice
limit? Can't remember.
Anyway, it's something like that. It's
where, water ceases to be a vapor
and becomes ice. so
beyond the orbit of Mars,
things, things basically freeze.
if, if, if you've got water vapor. and
that is thought to be why the gas giants
grew so big, the four gas giants,
because, the fact that their water is
actually the commonest two element molecule in the whole
universe. so if the water
vapor becomes something solid, beyond
that that ice limit, then, then
you're going to get the collection
of much more mass in
a planet that's being built by this process of
accretion. so because the water is now in
a solid form, you can build a much bigger planetary
core. and that is why you
can then get something big enough that it actually hangs onto the
gases surrounding it and you've got a gas giant.
So that's the picture that we imagine is
the way planets form. So
just turning to Dean's question. Was Earth in a
belt of the protoplanetary disk where liquid water
orbited? it wouldn't have been liquid because
you can't have liquid in a
vacuum. but you can get water
molecules in vapor form
basically or in the form of ice.
And yes, there would have been a step there I think in the
protoplanetary disk where the ice
solidified, where you've got solid ice. so
I think that's a really good question and I
believe I've seen some
papers recently, which suggest that
we are actually observing that in fact, very
recently, I think it might even have been last week, Heidi, there
was a paper that reported the detection
of ice in a protoplanetary disk.
so that's one to check out. it's yeah,
it's there and in the inner regions it's
probably too warm for it to exist as a
solid material.
Heidi Campo: So Dean's, Dean's onto something. We get a lot
of really smart people who follow along this show too.
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Now back to the show.
Generic: Three, two, one.
Space Nuts.
Heidi Campo: Our next question comes from Ron. And he
says hello from upstate New York. Ron. That is
where my husband is from. I wonder if you're from the Catskills
area. Beautiful place, if any of you guys ever get to
visit.
Generic: Hello.
Heidi Campo: Ron says hello from upstate New York. I was
wondering, with the extreme lifetime of red
dwarf stars being one of the
order of trillions of years, could there be any
population of, I think that says of
population three. Sorry, Population three red dwarf
stars. Maybe I should ask first, do we think
red dwarf stars were formed right after the Big
Bang to be a part of the population 3 stars?
Thank you for considering my question and
always informative podcast from Ron.
Professor Fred Watson: Thanks, Ron. and greetings to upstate New
York. yeah, that's another.
They're all great questions that we count space
nuts. and it's a very
intelligent one as well. And just to sort of give the
backstory of this Population three stars,
and it's usually written as a Roman three
stars. They're what we think of as being
the first stars to form in the
universe back probably within the
first 2 or 300 million years of the Big
Bang, which we believe happened 13.8 billion
years ago. so we.
What would signify a population three star? It would be
a star, whose spectrum, when you
analyze its light, reveals only the
presence of hydrogen and helium, because they were the
elements that were predominantly produced in the Big Bang. There were
a few other things produced in very, very small
quantities, like
lithium, but really it was mostly
hydrogen and helium that were produced in the Big Bang.
And so population 3 stars will be stars that
only show the signatures of those
chemical elements in their spectrum. We
haven't actually found any yet. We found some that look
very nearly like Population 3 stars, but they still
have a little trace of iron in them, the ones that have been found,
and iron is formed, in the
interior of stars. And so you know that anything that
shows up iron is not the first generation of stars
ever to exist because other stars have been there
first, and have formed the iron. So
population three stars are a bit of a holy grail, actually.
Trying to find Them, I've worked with, people
here in Australia whose sole scientific
mission has been to find population, three stars. And they've come
pretty near it with these very early, what we call
metal pore stars. Metals, unlike
the way we think of metals in everyday life,
things that contribute steel and brass and
stuff like that, metals are anything other than hydrogen and
helium. To an astronomer it's a very curious
expression. so metal poor stars are ones
that don't have much of anything other than hydrogen, helium.
So the cutting to the nub of
Ron's question though, we think the very
first generations of stars to form
in the universe were not, were
not red dwarfs. we don't think they were dwarf
stars at all. We think they were
very massive stars, perhaps 20,
maybe even up to 100 times the mass of the sun,
that had very short lives, and
exploded, you know, within perhaps less than a
million years. Such a short life that,
remember our sun is four, and a half
billion years old and it's in its sort of middle age,
midlife, not a crisis, but a midlife term.
So red dwarfs probably did not form in the early
universe. And in any case, what
categorizes a red dwarf star, is
actually the fact that
it has seen many generations of
stars before it because they're rich
in all kinds of different chemical elements,
not just hydrogen and helium. they are
basically, you know, cool
stars, which show the characteristic
signatures of all sorts of things, even molecules.
I think some molecules. Molecules don't usually exist in
stars because they get torn apart. The atoms get torn apart by
the heat. But I think red dwarf stars have some
molecular signatures as well. so the answer
is, I think no. red dwarf stars weren't formed right
after the Big Bang. And there probably aren't
any population three red dwarf stars. But you're absolutely right
that the lifetime of red dwarf stars is very, very long.
Maybe, up to trillions of years as you've suggested. Ron,
thanks very much for the question.
Heidi Campo: Very interesting, very interesting indeed.
Andrew Dunkley: Okay, we checked all four systems.
Professor Fred Watson: Space nets.
Heidi Campo: Our very last question is another
great question from Jake Johnston.
He says. Hey, space nuts, quick question.
While it is totally possible that there is no
life in our solar system except for on Earth, if
you had to guess where the most likely
other place in our solar system is to find
either current or ancient life,
what would you choose? Titan. Mars.
Thanks.
Professor Fred Watson: let's give you a shot at this one, Heidi. What do you think the answer to
that would be?
Heidi Campo: Oh, you know, I was actually thinking in my head of playing a joke
and just saying some random planet and then going, oh,
oops, he must have meant this for you.
I don't know. I really think that
it's gonna, for some
reason I think there's probably something on a moon
somewhere because
I'm just imagining
primordial solar system, everything's
crashing into each other and when
it, when that matter ends up on a
planet it's getting churned through its
core and getting heated up and everything that
maybe existed, even bacteria, is just getting cooked and
destroyed. But on a moon it's not getting
that turnover. So I would assume,
and this is with my background not in this at all, I would
assume that we would find something on a moon.
Professor Fred Watson: I think you're right actually. so I
guess the most obvious
places to look, first of all Mars,
Mars we know has been warm and wet
in the past. we know that it was warm and wet at a time
when the first living organisms were forming on Earth.
So if all you need is the right atmospheric conditions
while they were there on Mars. And so
Mars may show signs of ancient
microbial life. Unfortunately we don't at the moment have the
wherewithal to find it. We've got samples
of rocks and soil that have been taken by the
Perseverance rover on Mars which are stashed away for a
future mission to go and collect them. Sadly
that mission is a bit in doubt at the moment because it's
turned out to be very expensive. but there may be evidence
on Mars. but you're
absolutely right that some of the moons of the solar
system are perhaps the next on the list
because first of all, and this is the
one that's really the poster child of looking for life on moons
in the solar system is Europa.
Europa, one of Jupiter's moons, which we
know has a rocky core, it's got a liquid water
ocean over that core, and that is
sealed in by a layer of solid ice on top of
it. And we have seen evidence of
geysers of ice,
crystals coming through that
layer of ice because of cracks in it.
there is evidence as well that there are
quite complex carbon containing molecules,
on the surface of Europa got a
reddish brown colour which looks as though
it's the effect of sunlight
and solar radiation on these carbon containing molecules.
So the ingredients for life might very well be there.
likewise, further out in the solar system,
Enceladus, Saturn's moon which was explored
by Cassini, that definitely has these geysers of
ice crystals because we've seen them and in fact Cassini
flew through them and measured some of the contents,
of them. in terms of it's mostly water
ice, but there's also molecular hydrogen and some other
really interesting ingredients that suggest that there are
geothermal vents down at the bottom of
Enceladus oceans. Maybe that is where
life could have kicked off. We think life might have
kicked off on Earth down in hydrothermal vents, maybe
on Enceladus too. And you know, Dean
mentions also Titan. I, beg your
pardon, Jake. I'm sorry, Jake, the wrong name
there. Jake also mentions Titan, which
is another of these ice worlds with the same sort of
structure and a liquid ocean, but it's also got
these lakes of methane and ethane, natural
liquefied natural gas. The only
place we know anywhere in the universe other than
Earth where there's liquid in equilibrium
with an atmosphere. And Titan has a thick
atmosphere, mostly carbon dioxide, but hydrocarbons in there
as well. So these are all great
candidates for living organisms. and if I had
to pick one, let's go with Titan
because I think you get two shots at it there. There might
be water, based life in the oceans
underneath the surface, but there might also be carbon,
some weird carbon based life in the
liquid, natural gas, lakes and seas on
Titan. And we might find that when the Dragonfly
spacecraft visits Titan later, in.
Heidi Campo: The decade, these are
all very exciting.
I mean there is just so much happening in space
right now. Every single week we are closer
and closer to new breakthroughs and new
discoveries. and I'll even share a program
that I'm a part of that anybody who is a
high school, or like if you're in high school,
if you're doing your undergrad graduate or early career
professional, you can join this too. It's called the L
space, so l apostrophe space
program. And it is a competitive proposal
writing program where they select
different individuals. So you can apply. I'm in the summer program right
now, but you can apply for the fall program. But all of
us got put into different interdisciplinary teams
and we are going to be coming up with a
proposal that is going to address one of
NASA's gaps. And they have a whole
training on how to write proposals the way NASA wants
them written and the taxonomy of everything they're looking
for. And the gaps that need to get filled. But the
cool thing is, is that, the proposals
that we come up with, one, of them will be selected as the
winner. And the winner will get thousands of dollars of
grant money and it will probably go on to become a
real project. So if you are
an engineer, even a high school or early
career professional or anyone in between who
feels like you have a lot of good ideas for discovering
these kinds of things, like I've been co hosting
now for a while and I've seen how smart you guys are.
So I would really encourage you to all get involved
and use your, creativity to help
push humanity forward into the stars.
Because every single one of you has something to add.
And never, ever, ever let imposter syndrome get in the way of
that. Because every creative mind
add something to all of this. And that's my,
that's my rah rah for this week.
Professor Fred Watson: Remind us again what the program's called.
Heidi Campo: It's L Space. So it's an L
apostrophe and then S, P, A, C, E.
And the program that I'm in, they have several different programs.
So I'm in the, proposal writing.
So np, W, E, E.
NASA Proposal writing Experience.
Something, something, something, something. It's.
They love, they love acronyms.
They just. They, But yeah, L, Space. and you can look
that up. I can probably send the link to that
to you guys to post, in the
link and the description of this episode if anybody is
interested in adding to
their contributions into space.
Professor Fred Watson: Fantastic. great program. and
I look forward to checking out on the Web.
Heidi Campo: On the Web, absolutely. Well, thank you so much, Fred. This
has been another wonderful Q A
session of Space Nuts. We'll catch you.
Professor Fred Watson: Thank you.
Heidi Campo: We'll catch you all next week. Bye for now.
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