Latest / Space News Today / Martian Meteorites, Gas Giants & The Search for Alien Life | Q&A | Space Nuts: Astronomy...

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Martian Meteorites, Gas Giants & The Search for Alien Life | Q&A | Space Nuts: Astronomy... · Space News Today

0:00
Hello again. Thanks for joining us. This
0:01
is a Q&A episode of Space Nuts, where we
0:05
answer astronomy and space science
0:07
questions from our audience. Today,
0:10
David wants to know about Mars meteor
0:12
showers. Penny is asking about fly
0:15
through missions for Saturn and Jupiter.
0:17
That could be messy. Uh Andy is asking
0:20
about the gravitational effect of
0:22
Jupiter on its uh moons, particularly
0:25
Europa. And Duncan wants to talk about
0:28
alien civilizations. We will deal with
0:31
all of that and more on this episode of
0:34
Space Nuts.
0:35
>> 15 seconds. Guidance is internal. 10 9
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Ignition sequence start.
0:41
>> Space Nuts.
0:42
>> 5 4 3 2 1 2 3 4 5 4 3 2 1
0:47
>> Space Nuts.
0:48
>> Astronauts report. It feels good.
0:51
>> This is Fred Watson's favorite segment.
0:53
He's back again for more. Professor Fred
0:56
Watson, astronomer at large. Hello.
0:58
Hello, Andrew. How are you?
1:00
>> I am quite well. It's been a long time,
1:02
like I don't know, two or three minutes.
1:07
>> Hope nobody's guessed that we record
1:09
these in pairs. But never mind. Never
1:10
mind.
1:11
>> If they haven't figured it out by now,
1:13
they probably never will.
1:16
>> That's right.
1:17
>> I'm pretty sure most people know how it
1:19
works. I mean, they just have to look at
1:20
the shirts we're wearing every week.
1:24
That's if they do it on the YouTube
1:25
channel. Although I don't know if I
1:27
don't know if they put the video on
1:28
anymore because um it could be could be
1:31
a bit bit of a turnoff. So I don't know.
1:33
Um anyway, uh all is well with you. I
1:37
trust
1:38
>> it is. Thank you. Yes. All good.
1:39
>> I already knew the answer, but we have
1:41
to ask because you know this is just to
1:43
be bal.
1:44
>> Yes, that's it. Exactly. Um what why
1:46
don't we try and answer some questions?
1:49
>> Oh, all right. If you must.
1:51
>> Well, you do it. I'm just going to push
1:53
him in there. Uh, let's go to our first
1:55
question. It comes from David
1:57
>> David Thompson here from Spring in the
2:01
UK. Back to Mars. As a child of the 50s
2:06
and 60s,
2:08
uh, reading the comics
2:11
at the time, there was always a risk of
2:14
meteor showers. I'm just wondering given
2:18
that Mars atmosphere is not as dense as
2:23
the Earth's
2:24
whether smaller meteorites would be able
2:28
to
2:30
hit the surface of Mars and be a real
2:36
hazard to anybody putting a house there.
2:41
Find the podcast absolutely amazing.
2:45
Everybody have a great day. Bye.
2:48
Thank you, David. Thanks for those kind
2:49
words. I'm glad you're enjoying the the
2:52
podcast. Uh so, we're back to Mars. I
2:54
didn't push him there. I didn't. Um
2:57
everyone knows I love Mars, but uh yeah,
2:59
meteor showers. Uh he makes up He brings
3:02
up an interesting point. It's got a much
3:04
less significant atmosphere than Earth.
3:07
So, does that mean smaller things can
3:09
get through?
3:11
>> It does. Yes, it does. Uh David's
3:15
absolutely right. Uh I'm delighted we've
3:17
got a listener in Horton Lispring. I um
3:20
used to drive past there very very
3:22
frequently. It's between Durham and
3:24
Sunderland in the north of England. And
3:26
I was a very very regular user of the
3:30
A1M which goes right past Horton the
3:32
spring. Uh and it's lovely to hear your
3:34
voice, David, and hear that lovely North
3:37
Durham accent there. Um the answer is
3:40
yes. Uh uh so because the atmosphere you
3:44
know the atmospheric pressure on Mars is
3:46
I think it's 6% of our atmospheric
3:48
pressure which means that meteorites
3:51
coming in are going to have a lot less
3:53
resistance. Um we know of meteorites on
3:56
Mars. Many have been identified by both
3:59
Curiosity and Perseverance uh usually by
4:02
their but by their color, but both those
4:06
um rovers were equipped with laser
4:08
zappers that could give us an idea of
4:10
their content. And some of those
4:11
meteorites have been found to be
4:12
metallic. Uh so meteorites on Mars are
4:16
something that happens. And yes, there's
4:17
probably a higher risk of uh of damage
4:20
from an incoming meteorite on Mars than
4:24
on Earth. um because uh the likelihood
4:27
is that their terminal velocity uh the
4:31
sort of final velocity after they've
4:32
passed through the atmosphere will be
4:35
much higher than it will be on Earth
4:36
just because of that lower pressure.
4:38
>> Uh and so yes um me meteorite protection
4:42
might turn out to be quite an important
4:44
aspect of putting humans on Mars. We
4:47
haven't had any reports of you know
4:51
there's how many rovers have been on
4:53
Mars now? I can think of one, two,
4:55
three, four, five, six.
4:58
>> At least six, probably more like seven
5:00
or eight. Uh they are um Andrew is
5:04
googling it as we speak.
5:06
>> Yeah.
5:07
>> Six.
5:08
>> Six rovers. Sojourer, Spirit,
5:10
Opportunity, Curiosity, Perseverance,
5:13
and uh Jirong, the Chinese mission.
5:16
>> The Chinese one. That's right. Yeah,
5:18
that So I did get the right answer. Six.
5:20
>> Yeah. Uh yeah, it's um so uh none of
5:25
those as to the best of our knowledge
5:28
has suffered any kind of meteoritic
5:30
impact. So at least so far so good in
5:34
terms of our understanding of the
5:37
meteorite hazard on Mars. But a good
5:39
question to raise David and gives us
5:42
always always gives us a chance to talk
5:43
about Mars. He he did ask about the
5:46
danger to housing
5:48
on Mars. They probably won't build
5:51
houses on Mars like they do on Earth and
5:53
and the because of the radiation issues,
5:55
they're probably going to have to go
5:57
underground which would um protect them
6:00
from anything like that. But there will
6:02
be surface something or other there one
6:04
day.
6:05
>> So that's infrastructure.
6:06
>> Yeah. Perhaps domes that they could be
6:09
susceptible maybe. Yeah, it looks like I
6:13
mean what what we imagine is something
6:15
like White Cliffs in uh Western New
6:17
South Wales where people live
6:19
underground.
6:20
>> They do.
6:20
>> And that's just to get out of the heat.
6:22
Um
6:23
>> so
6:24
>> that's that's radiation.
6:26
>> Yes, it is solar radiation. That's
6:28
right.
6:29
>> Yeah, indeed.
6:30
>> Yeah. I thought of another question. Um
6:32
we Yeah, here it is. Uh we are
6:35
constantly monitoring for big objects
6:38
that could be threatening to Earth,
6:40
things that could destroy cities or
6:42
regions or god forbid the planet itself
6:45
as we know it. Uh what about Mars? Do we
6:48
keep an eye on anything that might hit
6:50
that? Um so yes to some extent if you
6:55
you know if you can identify near-Earth
6:58
objects uh and look at their orbits you
7:02
would certainly find out um from the
7:04
analysis very quickly if there was any
7:06
risk of one of those hitting the planet
7:09
Mars but there's probably many small
7:11
objects in the vicinity of Mars because
7:13
it's closer to the asteroid belt than we
7:15
are uh which are undetectable from the
7:18
distance of Earth. Uh, you know, objects
7:21
that might even be as big as Phobos,
7:23
Mars's biggest moon.
7:25
>> Uh, we we we would be able to detect
7:27
that from Earth quite easily. But, um,
7:29
as we obviously can, it was discovered
7:30
in the 1800s. Uh but you know if you had
7:33
something that was only a few tens of
7:36
meters across uh which could pose a
7:39
hazard uh to houses on Mars um that uh
7:44
would be hard to detect from the
7:46
distance of Earth unless it be unless it
7:48
was also a near-Earth object. So it was
7:50
coming uh close to closer to our
7:52
telescopes.
7:53
>> Yeah. Uh there'd be nothing much we
7:56
could do about a big thing hitting Mars
7:58
anyway is there? Or there'd be a good
7:59
experiment if we wanted to test our
8:01
capabilities. Well, that's right. If
8:03
there was, you know, the the bigger ones
8:04
are the the ones that we know more
8:07
about, uh, because they're easier to
8:09
see. Uh, if something like that was
8:11
looking as though it might collide with
8:13
Mars,
8:14
>> yes, it might be a good time to test out
8:17
the theories that were put into place
8:19
with the Dart mission a few years ago,
8:21
see whether it'll actually work on
8:22
something a bit bigger than that.
8:25
One can only wonder, but um hopefully we
8:28
don't ever have to put it to the test
8:30
for for ourselves. But uh yeah, you just
8:33
never know. There's always something
8:35
going on out there. There's so much
8:36
stuff bumping into it. There's something
8:38
else out there. It's it's only a matter
8:40
of time before one of them carines into
8:43
our sector and becomes a potential
8:46
threat. Although we seem to be finding
8:48
them more and more now, don't we
8:50
>> with with and that's the the good news
8:52
part of this story. two good news sides
8:54
of this story. One is that the big ones
8:56
are the easiest to find and the other is
8:58
that we've been finding these things now
9:00
for the last 40 years and have a good
9:02
idea of what the Earth's environments
9:04
like.
9:05
>> Yeah, great to hear from you, David.
9:07
Great question and uh thanks for sending
9:09
it in. Our next question comes from
9:12
Penny. It's a short quick one. I think I
9:15
know where this one might go too in
9:17
terms of an answer. As Saturn and
9:19
Jupiter are gas giants, are there any
9:22
plans to fly a spacecraft through the
9:24
middle of one or both of them?
9:27
Interesting question, Penny. Uh I do
9:29
recall um when you're talking about u
9:32
comet or asteroid impacts, the um the
9:35
impact with Jupiter uh many many years
9:38
ago that we we almost got footage of. It
9:41
was just quite not quite the right
9:43
angle, but we did see the aftermath of
9:45
it.
9:46
That's Schumaci the second one Jupiter
9:50
back
9:51
>> can't remember what year 94 I think it
9:53
might have been um so uh the issue is
9:59
that um the gas giant aspect of these
10:03
planets is really just their outer
10:05
envelope that's gassy u and we don't
10:08
really know what's underneath that. Uh
10:11
the likelihood is there will be a solid
10:13
core there. Uh it may be rocky. Some
10:16
have suggested that it will be made of
10:19
metallic hydrogen which is hydrogen in a
10:22
very unusual form. Uh so you've got a
10:25
core of something called metallic
10:26
hydrogen. So um flying through is not
10:30
anything that's planned because it would
10:32
be impossible. But even if these gas
10:36
giants were sort of gaseous all the way
10:38
through, it still would be a very hard
10:41
thing to achieve because you're entering
10:44
an atmosphere that you'd have to slow
10:47
the rocket the spacecraft down
10:49
enormously in order to prevent it from
10:52
just melting by friction with the
10:54
atmosphere, which is what happened to
10:56
Cassini. Cassini was plunged into
10:58
Saturn's atmosphere at the end of its
11:00
mission in 2017. uh it didn't burn up
11:03
because there's no oxygen in Saturn's
11:05
atmosphere, but the friction made it
11:07
melt. Basically, it just melted and fell
11:09
to pieces. In fact, NASA produced uh
11:12
some real tearjerker footage of what
11:14
that might have looked like,
11:16
>> which we saw uh often at the end of the
11:19
Cassini mission. uh you know this thing
11:23
which had performed valiantly for the
11:25
previous 13 years and done a marvelous
11:28
job at revolutionizing our knowledge not
11:30
just of Saturn and its rings and moons
11:32
but also the way planets form and things
11:34
like that. Uh this footage of uh Cassini
11:37
hitting the top of Saturn's atmosphere
11:39
and having its antennas ripped off and
11:41
eventually just melting into becoming
11:44
part of the atoms of the atmosphere of
11:46
Saturn. And that is you, you know, any
11:50
mission to try and penetrate down
11:52
through the atmosphere would would
11:54
struggle uh because of the the rapid
11:58
increase in density, the fact that
11:59
you've got to slow the spacecraft down
12:01
in order to stop it just burning up by
12:03
friction. Um, I think one of the Jupiter
12:07
missions, I can't remember which one,
12:11
might have been Galileo, um, actually
12:14
sensed as it hits Jupiter's atmosphere
12:17
to burn up again or to to melt. I think
12:21
there were sensors on board that were
12:22
giving us some readings of what the
12:24
conditions were like.
12:26
>> Yeah. Um,
12:28
I I think the other big problem would be
12:30
pressure, wouldn't it? if you tried to
12:32
fly through.
12:33
>> Yeah. So, the pressure just goes up um
12:37
probably exponentially at some level.
12:39
>> Yeah. Uh and Penny might be interested
12:42
to know that there are some missions
12:44
slated for um the near future. Uh Europa
12:48
Clipper uh which will launch in or it's
12:52
already launched should be 20 yeah 2030.
12:56
Uh there's the juice mission which
12:58
launched in 2023 which arrives in 2031
13:02
and Dragonfly
13:04
um with with the um with the helicopter
13:07
um
13:07
>> off to Titan.
13:08
>> Yeah, we'll launch in 2028. So they
13:12
they're more interested in some of the
13:15
um moons around those gas giants, but um
13:18
yes, they are fascinating. And of
13:22
course, we're most interested in Europa
13:24
Clipper because we want to know if
13:26
anything's living in the ocean.
13:29
And maybe there is, maybe there isn't.
13:32
Who knows? It could just be made of
13:34
jelly. We we don't really know. Uh
13:36
although the juice mission is more
13:38
likely to figure all that out. Uh boom
13:40
boom. Um thank you, Penny. Lovely to
13:42
hear from you. This is Space Nuts Q&A
13:44
edition with Andrew Dunley and Professor
13:47
Fred Watson.
13:49
Let's take a break from the show to tell
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15:23
>> Okay, we checked all four systems and
15:25
with the go.
15:26
>> Space nuts. And speaking of uh Europa
15:30
and Jupiter, we've got a a question now
15:33
from Andy. This is Andy, the train
15:35
driver from London. Uh just got a
15:37
question about Europa. I know Europa
15:40
erupts because it's being sort of
15:42
squeezed by the gravity of Jupiter,
15:45
but what I don't understand is if Europa
15:48
is being affected by Jupiter's gravity,
15:51
why is it not just being pulled closer
15:53
to Jupiter? I thought gravity pulls
15:57
things down. Like when you throw a ball
15:59
in the air, gravity pulls it back down.
16:02
I don't understand how Europa is being
16:04
squeezed. Uh that suggests to me that
16:07
it's being affected by gravity from all
16:10
directions. So I squeeze it like a like
16:12
you could squeeze a tennis ball. Maybe
16:14
you can shed some light on this or tell
16:17
me that I'm barking up the wrong tree.
16:19
Anyway, thanks for the podcast, guys.
16:21
Really interesting. Uh and see you on
16:23
the next one. It's Jord's job to bark up
16:26
the wrong tree. But um that
16:30
>> nicely done, Andrew.
16:32
>> Um your point is well taken, Andy. Uh
16:35
it's not just Europa, though. Uh there
16:37
are several moons orbiting the gas
16:39
giants that that do get that squeeze
16:41
effect. Titan, I think, is is one of
16:43
them. And um oh, look, probably all of
16:47
them to some degree, but Europa, yeah,
16:49
it's it's it's in a difficult position.
16:53
Uh, it's a good question though. Why
16:55
don't they just get sucked in? Like our
16:57
moon doesn't, but we're not a gas giant.
17:00
>> No. Same thing happens to our moon,
17:02
though. Um, so, uh, it's actually
17:04
probably I think the moon that Andy's
17:06
thinking of is Io, which is the
17:09
innermost of the of the moons, the the
17:12
big moon, big four moons of Jupiter. And
17:14
it is the one that gets the most
17:16
squeezing and squashing u because of its
17:19
uh proximity to to Jupiter. Europa
17:23
probably also has the same phenomenon
17:25
and there there may be eruptions of it
17:28
on Europa that possibly um a bit like
17:32
Enceladus where you've got stuff
17:34
streaming out through the cracks in the
17:36
in the ice.
17:37
>> Uh but the the genuine volcanic
17:40
eruptions which they really are it's hot
17:42
lava uh is what take place on Eio the
17:45
innermost of those moons. So um the way
17:48
to understand this uh is to real
17:52
recognize that if you've got an object
17:56
in a very strong gravitational field
17:58
first of all let me just clarify the
18:00
reason why objects in orbit around other
18:03
objects don't just get pulled in. They
18:05
are getting pulled in but they've got a
18:07
forward motion that compensates for the
18:10
for the pull. So basically the the
18:13
motion of the object through space uh is
18:16
what balances out the gravity of a giant
18:19
like Jupiter. And so that you know the
18:22
the greater the gravity of a of a planet
18:25
the faster it satellites have to orbit
18:27
in order not to not to fall in. Um and
18:30
so that's that's the mechanism that
18:33
stops these things just immediately
18:36
being sucked in to Jupiter. They're
18:38
already moving and that comes about. Why
18:40
are they moving? Because they were
18:41
formed that way with the the way the,
18:44
you know, the planets and their
18:45
satellites evolved, the way they formed.
18:48
They're basically swirling around right
18:50
from the start. And that swirling motion
18:52
is what stops which is fossilized in the
18:55
in the planets themselves and and the
18:57
moons of the planets and stops them
18:59
falling into their parent object. But
19:02
the the squeezing and squashing comes
19:04
from what we call a tidal effect. And it
19:07
is actually exactly the same thing that
19:09
gives rise to tides on the earth. Uh but
19:11
let's concentrate for a minute on Io.
19:13
Here's this little world
19:16
right next to gas giant Jupiter. One
19:19
side of EO is feeling the gravitational
19:22
pull of Jupiter. The other side is as
19:25
well, but it's feeling slightly less
19:27
because it's further away because the
19:30
gravitational pull falls off as as the
19:33
distance squared. One over the distance
19:35
squared. So um further on the farther
19:38
side of EO from Jupiter it's going to
19:40
feel less force and that is what con
19:44
contributes to this tension that there
19:45
is uh and basically elongates the planet
19:49
slightly in the direction of Jupiter.
19:52
Now
19:53
why we talk about squashing and
19:55
squeezing is that throughout the orbit
19:57
of Vo which is not a planet it's a
19:59
satellite but around the orbit of Vo as
20:02
it goes around is not circular. So
20:05
sometimes that force is greater than
20:07
others that tension that's trying to
20:08
pull it apart. Uh it's greater than at
20:11
other times and and basically it's that
20:15
squashing uh stretching really is the
20:17
best word for it. As it goes round as it
20:20
goes around Jupiter uh that change in
20:22
the stretch force that's being applied
20:25
is what generates the heat that causes
20:27
these eruptions to continually take
20:30
place. So and that's called the tidal
20:32
effect. the fact that one side of a body
20:34
feels a different gravitational force
20:36
from the other. It's what makes us
20:38
susceptible if we fall into a black hole
20:40
to spaghettification.
20:42
Spaghettification is just a nicer word
20:44
than tidal effects.
20:46
>> Yeah. So, you've got a real combination
20:48
of of factors.
20:49
>> Yeah, that's right. You you've got the
20:50
the the gravitational effect, you've got
20:52
orbital dynamics.
20:54
>> Yep.
20:54
>> Um all sort of coinciding to keep these
20:57
things from falling into the planet, but
20:59
there's a tug of war going on.
21:01
>> Yeah. Uh I I saw a really good
21:03
demonstration online oh probably three
21:06
or four weeks ago on on how the tides
21:09
work on Earth. And of course most people
21:12
and I must confess guilt here assume
21:16
that the moon causes the water to rise
21:18
and then fall. But it's not. It's the
21:20
fact that the Earth is rotating, the
21:22
moon is orbiting, and there's always a
21:25
wave. It's just always there. And it's
21:27
just that when it um when the moon
21:30
reaches your vicinity that that lump of
21:33
water comes up.
21:35
>> Yeah.
21:36
>> And goes down again. It's it's not the
21:38
water so much rising. It's just it's
21:40
always risen in proximity to the moon.
21:43
>> Am I right?
21:44
>> Uh you are. You're partly right because
21:47
it's a bit more
21:48
>> I knew I missed something.
21:49
>> Yeah. And the that doesn't explain the
21:52
bulge on the other side because as you
21:54
know you get a high tide every every 20
21:57
hours not every 24 hours.
21:58
>> And that's because um again it's the
22:01
tidal effect. So the moon's pulling on
22:04
the ocean on the near side. It's also
22:07
pulling on the earth itself and that
22:10
leaves behind the water on the other
22:12
side. So you get a bulge
22:14
on each side. That's works.
22:18
>> Fascinating. Yeah. Yeah, it's worth
22:19
looking up that demo. Um I didn't read
22:22
the fine print obviously, but uh yeah,
22:23
that that makes sense. So the water's
22:25
being pulled, sort of dragging with it,
22:28
and then the water is being left behind
22:30
on the other side. So you got two
22:31
bulges.
22:32
>> Two bulges. Exactly. So
22:34
>> it's fascinating.
22:35
>> So
22:36
>> um and that's what's happening to all
22:38
these these moons in various ways. If
22:41
they have not water, something else is
22:42
being
22:43
>> Well, that's right. It's the rock. The
22:44
rock does it as well. The same is true
22:46
on Earth. We the rock goes up and down
22:48
as well. I've got a question for Andy,
22:50
though. Um if he's um ever getting back
22:54
to us, I'd like to know what sort of
22:55
trains he drives.
22:56
>> Uh because um yeah, I'm a bit of a train
22:59
nerd myself.
23:00
>> Train train drivers are my heroes.
23:03
>> Yeah. I live next door to a retired
23:06
train driver. So
23:07
>> yeah. Um but when we flew into do the
23:10
other day, I looked down at the rail
23:14
maintenance facility. It's it's a brand
23:16
new system uh facility that's just been
23:18
built in do and they're fitting out all
23:20
the new regional trains and you can see
23:22
them all lined up bright red all
23:25
>> getting ready to go. They're putting all
23:27
the furniture in them and uh uh the
23:30
Wi-Fi systems and yeah uh they'll be
23:33
rolled out pretty soon. Not not exactly
23:35
sure when, but um the plan is soon.
23:38
That's the answer to the question
23:39
officially. Have you um have you ridden
23:43
on um new metro trains here in Sydney?
23:46
>> Yes, I have. Yes.
23:47
>> So, you'll know that they drive 100
23:49
kilometer now with no driver. You can
23:50
stand at the front, look out the front
23:52
window, and pretend you're driving it.
23:54
>> Yeah. And I've done that in a taxi in
23:56
San Francisco.
23:57
>> Oh, yes, you have.
23:58
>> Drives driverless taxis.
23:59
>> Driverless taxi.
24:00
>> That's next level. That's just amazing.
24:02
But yeah. Yeah.
24:04
>> Pretty incredible stuff.
24:05
>> Thanks, Sandy. Um really enjoyed that
24:08
question. And uh yeah, if you want to
24:10
tell us what sort of train you drive,
24:11
send us another message. We'd um we'd
24:13
love to find out.
24:16
>> I'm going to step off the land now.
24:20
That's one small step for man,
24:26
one lead for mankind.
24:28
>> Space nuts.
24:30
>> Our final question today, Fred, comes
24:33
from Duncan. He said, "I've heard that a
24:36
group of astrophysicists have calculated
24:38
that there are an estimated 1,000 alien
24:41
civilizations spread across the Milky
24:43
Way, but the Milky Way is 100,000 light
24:46
years across. How far away would an
24:49
advanced civilization have to be in
24:51
practical terms to be uncontactable?"
24:54
Uh, in other words, uh, are we
24:56
realistically given the distances
24:59
involved effectively alone?
25:02
Uh yes is the answer.
25:04
>> Yeah.
25:04
>> Uh and it's not just about the distance.
25:08
It's also about the time.
25:10
>> Um because a thousand civilizations
25:13
with a in a galaxy that's 12 billion
25:16
years old. Uh they might well have
25:18
turned up and gone long ago or still be
25:21
in the future.
25:22
>> Assume that we all coexist.
25:25
>> That's right. And we probably don't.
25:27
There's actually um a really nice piece
25:30
now. Let me see if I can find it. Uh to
25:32
direct uh Duncan to it. Uh it's um on
25:37
one of the um SP the science media came
25:40
in today. So actually I think is where
25:44
is it? Sorry, I've lost it. Uh yeah. Uh
25:47
it's it's basically a summary of
25:49
thinking by the likes of uh Richard
25:52
Fineman uh and other great minds. Um and
25:56
the bottom line is it's exactly what
25:59
I've been saying. It's not just the
26:00
distances, it's the time uh that you're
26:04
the era in which you live. And it's very
26:07
unlikely that we'd find communicable
26:11
civilizations
26:13
um within the same time zone that we're
26:16
living in, if I can put it that way.
26:18
It's actually on uh it is on again on
26:20
the brighter side of news. Uh and the
26:23
headline is a really very very
26:25
thoughtful article, well worth a read.
26:27
Interstellar travel is impossible and
26:30
aliens haven't visited the earth,
26:31
physicists say. And it's because the
26:33
laws of physics basically make any kind
26:36
of travel uh or or even communication
26:39
extremely difficult. The laws of physics
26:41
are very rigid uh worth having a look
26:43
at.
26:44
>> Yeah. Yeah. Indeed. Uh although there's
26:46
this new book that I know that's been
26:48
written that kind of is counter to all
26:50
that, but you can do that in science
26:52
fiction
26:54
>> quite. So yeah, that's that's why it's
26:57
called science fiction.
26:59
>> Yes, that's that's what it is. Uh by by
27:02
way of example though, if I may, um
27:05
Duncan, uh if you were to be aware of a
27:09
an advanced communicative civilization
27:11
on a rocky planet orbiting Alpha
27:14
Centator, for example,
27:17
um and you sent them a message, it would
27:21
take, I'm just trying to remember, 4.37
27:26
years to get there. And that means a
27:28
return message if they answered you
27:30
immediately
27:32
would mean that you would not get a
27:34
reply for 8.74 years. Yep. Give or take.
27:38
But let's round that out to a decade
27:40
because you know what the bureaucracy is
27:41
like around Alphasi. They're not going
27:43
to you know they're going to they're
27:45
going to take a couple of years to
27:46
figure out what they want to say.
27:50
>> But that's the reality of it, isn't it?
27:51
And that's our nearest potential
27:54
>> y
27:55
>> neighbor.
27:56
It's it's it's true and um I mean the
28:00
point that this article makes is uh you
28:03
know we we live in a bubble of radio
28:06
radiation which are all the trans
28:08
transmissions from earth that's now
28:10
basically 100 uh light years in rad in
28:14
radius because we've been sending radio
28:16
transmissions for about 100 years. Um
28:19
and all right what's that 100 divided by
28:22
it's a thousandth of the diameter of the
28:24
galaxy. Uh and so you know it's hardly
28:27
any distance at all. Uh so yeah it's
28:32
it's an unc in a way an uncomfortable
28:35
reality. Uh to all intents and purposes
28:38
we're alone. We're uncontable. We are
28:40
alone. That's it. Good side cuz we're
28:42
unlikely to be picked on by any
28:44
voracious uh aliens. But Yep.
28:48
>> Yeah. Um yeah. I think we got to be
28:51
realistic about it. Even if there are a
28:53
thousand alien civilizations with
28:56
advanced technology in our our galaxy,
29:01
we are probably never going to be in a
29:03
position to communicate with them or and
29:06
and certainly not be able to travel to
29:07
them in any um meaningful way. And so
29:12
even if we're not alone, we are alone.
29:15
>> Yes, that's right. Exactly. um you know
29:19
that of that uh thousand civilizations
29:22
maybe 500 of them have been and gone and
29:24
500 of them are yet to evolve.
29:28
>> Do do you um concur with that estimation
29:31
or you don't think it's
29:32
>> um I look uh I have seen similar figures
29:36
being quoted uh not that there's that
29:38
number of civilizations but that there
29:40
might be that sort of number of
29:41
habitable planets that might be
29:43
earthlike.
29:45
Um,
29:46
>> we don't know whether being Earthlike
29:48
necessarily means you evolve an
29:50
intelligent species.
29:52
>> Of course, it has done it once, but
29:54
>> but the only time
29:55
>> could be and because the circumstances
29:57
have to be perfectly right. Although we,
29:59
you know, we're assuming humanoid type
30:02
carbon based life forms, but there could
30:04
be others out there that were created a
30:06
completely different way.
30:08
>> Yeah. So,
30:10
yeah, that's that's the stuff of
30:11
imagination at the moment, but it's a
30:13
possibility, I suppose. Uh, and of
30:15
course we'll look like deals next week
30:17
when a massive alien mother ship sets
30:20
itself down on top of the White House.
30:22
And
30:24
>> yeah, to rescue us all.
30:26
>> Maybe,
30:28
maybe. Oh gosh. Thanks, Duncan. Thanks
30:31
to everybody who sent in questions.
30:33
Please send them in to us. Oh, I I do
30:35
have a bit of homework sort of. Um, we
30:37
got a question twice now. I've received
30:39
it from Mike in New York. Uh Mike, you
30:42
you sent us a question in about black
30:44
holes, uh an audio question. The whole
30:47
guts of the question got cut off somehow
30:49
and so we got the the first we got your
30:52
preamble, then you started asking the
30:54
question, then there was about 5 hours
30:56
of nothing, probably about four, you
30:58
know, 20 seconds, and then we heard you
31:01
say goodbye. So, we don't actually have
31:02
the question. So, if you'd like to send
31:05
it again, uh please do. Uh, I don't know
31:07
what happened there, but um, you know,
31:09
it's the internet, so that's what that's
31:11
what happened there. Uh, but yeah, Mike
31:14
um would love to get that question so we
31:16
can run with it. And any questions you
31:18
want to send in via the ask me anything
31:20
tab at the top of our website,
31:21
spacenutspodcast.com,
31:23
spacenuts.io.
31:25
And don't forget to tell us who you are
31:27
and where you're from. Thank you, Fred,
31:29
as always. It's been a lot of fun.
31:31
>> Absolutely. It's great questions. Good
31:33
to hear everybody's voice and um, nice
31:35
to see their questions. Thank you.
31:36
Indeed. Uh that's Professor Fred Watson,
31:39
astronomer at large. And thanks to Hugh
31:40
in the studio. Um couldn't be with us
31:43
today. He got stopped by border security
31:46
and they realized he was an alien. He
31:48
comes from New Zealand. It made sense.
31:50
So he's been arrested. Uh he might be
31:52
back next week. And from me, Andrew
31:53
Dunley. Thanks for your company. We'll
31:55
catch you on the next episode of Space
31:57
Nuts. Bye-bye.
31:58
>> Space Nuts. You've been listening to the
32:01
Space Nuts podcast
32:04
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