Kind: captions
Language: en
I think it's actually not that hard to
imagine we are the only civilization in
the Galaxy right now living yeah that's
that's currently extent but there may be
very many extinct civilizations if each
civilization has a typical lifetime
comparable to let's say AI is the demise
of our own that's only a few hundred
years of technological development or
maybe 10,000 years if you get back to
the neic re Revolution the dawn of
Agriculture you know hardly anything in
Cosmic time span um that that's nothing
that's the blink of an eye and so it's
not surprising at all that we would
happen not to coexist with anyone else
but that doesn't mean nobody else was
ever here and if other civilizations
come to that same conclusion and
realization maybe they scour the Galaxy
around them they find any evidence for
intelligence then they have two options
they can either give up on communication
and just say well it's never going to
happen uh we just may as well just you
know worry about what's Happening Here
on their own planet or they could
attempt communication but communication
through
time the following is a conversation
with David Kipping an astronomer and
astrophysicist at Columbia University
director of the cool worlds lab and he's
an amazing educator about the most
fascinating scientific phenomena in our
universe I highly recommend you check
out his videos on the Cool World's
YouTube channel David quickly became one
of my favorite human beings I hope to
talk to him uh many more times in the
future this is Alex Reedman podcast to
support it please check out our sponsors
in the description and now dear friends
here's David
Kipping your research at Colombia is in
part focused on what you call cool
worlds or worlds outside our solar
system where temperature is sufficiently
cool to allow for moons rings and Life
to form and for us humans to observe it
so can you tell me more about this idea
this place of cool world
yeah the history of discovering planets
outside our solar system was really
dominated by these hot planets and
that's just because of the fact they're
easier to find when the very first
methods came online these were primarily
the Doppler spectroscopy method looking
for wobbling stars um and also the
transit method and these two both have a
really strong bias towards finding these
hot planets now hot planets are
interesting the chemistry in their
atmosphere is fascinating it's very
alien um an example of one that's
particularly close to my heart is tra 2B
whose atmosphere is so dark it's less
reflective than coal and so they have
really bizarre photometric properties
yet at the same time they resemble
nothing like our own home and so it said
there two types of astrophysicists the
astrophysicist who care about how the
universe works they want to understand
the mechanics of the Machinery of this
universe why did the big bang happen why
is the universe expanding how are
galaxies formed and there's another type
of astrophysicist which perhaps um
speaks to me a little bit more it
Whispers into your ear and that is why
are we here are we alone are there
others out there and ultimately along
this journey the hot plants aren't going
to get us there we when we're looking
for life in the universe seems to make
perfect sense that there should be plets
like our own out there maybe even moons
like our own planet around gas giants
that could be habitable and so my
research has been driven by trying to
find these more tulous globes that might
resemble our own Planet so they're the
ones that lurk more in the shadows in
terms of how difficult it is to detect
they're much harder they're harder for
several reasons the method we primarily
use is the transit method so this is
really eclipses as the planet passes in
front of the star it blocks out some
Starlight the problem with that is that
not all planets pass in front of their
star they have to be aligned correctly
from your line of sight and so the
further away the planet is from the Star
the cooler is the less likely it is that
you're going to get that geometric
alignment so whereas a hot Jupiter about
1% of hot Jupiter's will transit in
front of their star only about uh 05%
maybe even a quarter of a percent of
earthlike planets will have the right
geometry to Transit and so that makes it
much much harder for us what's the
connection between temperature of the
planet and geometric alignment
probability of geometric alignment
there's not a direct connection but
they're connected by an intermediate
parameter which is their separation from
the Star so
the planet will be cool if it's further
away from the Star which in turn means
the probability of getting that
alignment correct is going to be less on
top of that they also Transit their star
less frequently so if you go to the
telescope and you want to discover a hot
Jupiter you could probably do in a week
or so because the orbital periods of
order of one 2 3 days so you can
actually get the full orbit two or three
times over whereas if you wanted to set
an earthlike Planet you have to observe
that star for 3 four years and that's
actually one of the problems with Kepler
Kepler was this very successful mission
that NASA launched um over a decade ago
now I think and it discovered thousands
of planets it's still the dominant
source of exoplanets that we know about
but unfortunately it didn't last as long
as we would have liked it to it died
after about 4.35 years I think it was
and so for an earthlike Planet that's
just enough to catch four transits and
four transits was kind of seen as the
minimum but of course the more transits
you see the easier it is to detect it
cuz you build up signal to noise if you
see the same thing tick ti ti tick the
more ticks you get the easier is to find
it and so it was really a shame that
Kepler was just at the limit of where we
were expecting it to start to see
earthlike planets and in fact it really
found zero zero planets that are around
stars like the sun are orbit similar to
the Earth around the Sun and could
potentially be similar to our own planet
in terms of its composition and so it's
a great shame but um that's why it gives
a strong is more to do in the future
just to clarify the transit method mhm
is our primary way of detecting these
things and what it is is um when the
object passes udes the source of light
just a tiny bit a few pixels and from
that we can infer something about its
mass and size and distance and geometry
all all of that that's like trying to
tell what uh
at a party you can't see anything about
a person but you can just see by the way
they include others so this is the
method but is this a super far away how
many pixels of information do we have
basically how high resolution is the
signal that we um that we can get about
these
occlusions you're right in your
description I I think just to build upon
that a little bit more it might be
almost like your vision is completely
blurry like you have an extreme you know
H prescription and so you can't resolve
anything everything's just blurs and but
you can tell that something was there
because it just got fainter for a short
amount of time something someone passed
in front of a light and so that light in
your eyes would just dim for a short
moment now the reason we have that
problem with bless or resolution is just
because the stars are so far away I mean
these are the closest stars are four
light years away but most of the Stars
kept looked at were thousands of light
years away and so you there's absolutely
no chance that the telescope can
physically resolve the star or even the
separation between the planet and the
star is is too small especially for a
telescope like Kepler it's only a meter
across in principle you can make those
detections but you need a different kind
of telescope we call that direct Imaging
and direct Imaging is a very exciting
distinct way of detecting planets but it
as you can imagine is going to be far
easier to detect planets which are
really far away from their star to do
that because that's going to make that
separation really big and then you also
want the star to be really close to it
so the nearest Stars not only that but
you would prefer that planet to be
really hot because the hotter it is the
brighter it is and so that tends to bias
direct Imaging towards plants which are
in the process of forming so things
which have just formed the planet still
got all of its primodial heat embedded
within it and it's glowing we can see
those quite easily but for the planets
more like the Earth of course they've
cooled down and so we can't see that the
light is pitiful compared to a newly
formed planet we would like to get there
with direct Imaging that's the dream is
to have the pale blue dot an actual
photograph of it maybe even just a one
pixel photograph of it but for now the
entire solar system is one pixel with
certainly with Transit method most other
telescopes and so all you can do is see
where that one pixel which contains
potentially dozens of planets and the
star maybe even multiple Stars dims for
a short amount of time it dims just a
little bit and from that you can infer
something yeah I mean it's it's like
being a detective in the scene right
it's very it's indirect clues of the
existence of the planet it's amazing
that humans can do that we're just
looking out in these immense
distances and looking you know if
there's alien civilizations out there
like let's say one exactly like our
own we like would we even be able to see
an earth that passes mhm in the way of
its sun and slightly dims and that's the
only sign we have of that of that alien
humanlike civilization out there is it's
just a little bit of a dimming
yeah I mean depends on on the type of
star we're talking about if it is a star
truly like the sun the dip that that
causes is 84 parts per million I mean
that's just it's like the same as a um
as like a firefly flying in front of
like a giant flood light at a stadium or
something that's the kind of the
brightness contrast that you're trying
to compare to so it's it's extremely
difficult detection and in the very very
best cases we can get down to that but
as I said we don't really have any true
Earth analoges that have been in the
exlan candidate yet unless you relax
that definition you say it's not just
doesn't have to be a star just like the
sun it could be a star that's smaller
than the sun it could be these orange
dwarfs or even the red dwarf stars and
the fact those stars are smaller means
that for the same size Planet passing in
front of it more light is blocked out
and so a very exciting system for
example is trapis one which has seven
plets which are smaller than the earth
and those are quite easily detectable
not with a space-based telescope even
from the ground and that's just cuz the
star is so much smaller that the
relative increase in or decrease in
brightness is enhanced significantly cuz
that smaller size so trapis 1e it's a
planet which is in the right distance
for liquid water it has a slightly
smaller size on the earth um it's about
90% the size of the Earth about 80% the
mass and it's one of the top targets
right now for potentially having life um
and yet it raises many questions about
um what would that environment be like
this is a star which is 1/8 the mass of
the sun it's um stars like that take a
long time to come off their adolescence
when stars first form like the sun it
takes them maybe 10 100 million years to
sort of settle in to that main sequence
lifetime but for stars like these late M
dwarfs as we call them they can take up
to a billion years or more to calm down
and during that period they're producing
huge amounts of x-rays ultraviolet
radiation that could potent rip off the
entire atmosphere it may desiccate the
plants in the system and so even if
water arrived by comets or something it
may have lost all that water due to this
prolonged period of high activity so we
have lots of open-ended questions about
these M dwarf planets but they are the
most accessible and so in the near term
if we detect anything in terms of Bio
signatures it's going to be for one of
these red dwarf stars it's not going to
be a true Earth twin as we would
recognize it as having a yellow star
well let me ask you I mean there's a
million ways to ask this question I'm
sure I'll ask it about habitable
worlds let's just go to our our own
solar system what can we learn about the
planets and
moons in our solar system
that might contain life whether it's
Mars or some of the moons of Jupiter and
Saturn what kind of characteristics cuz
you said it might not need to be
earthlike what kind of characteristics
might we we' be looking for when we look
for life it's hard to Define even what
life is um but we can maybe do a better
job in defining the sorts of things that
life does and that provides um some
aspects to some Avenue for looking for
them um in the classically
conventionally I think we thought the
way to look for life was to look for
oxygen oxygen is a byproduct of
photosynthesis on this planet um we
didn't always have it certainly if you
go back to the Aran period um there was
you know you have this period called the
Great oxidation event where the Earth
floods with oxygen for the first time
and starts to saturate the oceans and
then into the atmosphere and so that
oxygen if we detect it on another planet
whether it be Mars Venus or an exoplanet
whatever it is um that was long thought
to be evidence for something doing
photosynthesis because if you took away
all the plant life on the earth the
oxygen would just hang around here as a
highly reactive molecule it would
oxidize things and So within about m
milon years you would probably lose all
the oxygen on planet Earth so that was a
conventionally how we thought we could
look for life and then we started to
realize that it's not so simple because
a there might be other things that life
does apart from photosynthesis um
certainly the vast majority of the
Earth's history had no oxygen and yet
there was living things on it so that
doesn't seem like a complete test um and
secondly could there be other things
that produce oxygen besides from Life um
a growing concern has been these false
positives in by signature work and so
one example of that would be photolysis
that happens in the atmosphere when
ultraviolet right hits the upper
atmosphere it can break up water vapor
the hydrogen splits off to the oxygen
the hydrogen is a much lighter Atomic
species and so it can actually Escape
certainly plets like the Earth's gravity
that's why we don't have any hydrogen or
very little helium and so that leaves
you with the oxygen which then oxidizes
the surface and so um there could be a
residual oxygen signature just due to
this fotsis process so we've been trying
to generalize and um certainly recent
years there's been other suggestions of
things we could look for in the solar
system Beyond uh nitrous oxide basically
laughing gas is a product of microbes um
that's something that we're starting to
get more interested in looking for
methane gas in combination with other
gases can be an important bio signature
uh phosphine as well and phosphine is
particularly relevant to the solar
system because there was a lot of
interest for Venus recently um you may
have heard that there was a claim of a
bio signature in Venus's atmosphere I
think it was like two years ago now and
the the judge and jury is still out on
that um there was a very provocative
claim and signature of a phosphine like
spectral
absorption um but it could have also
have been some of molecule in particular
sulfur dioxide which is not a bio
signature so this is a detection of a
gas in the atmosphere Venus and and uh
it might be controversial on several
Dimensions so one how to interpret that
two is just thr gas and three is this
even the right detection is this is
there an error in the detection yeah I
mean how much do we believe the
detection in the first place if you do
believe it does that necessarily mean
there's life there and um what gives how
can you have life in the Venus's
atmosphere in the first place because
that's you know been seen as like a hell
hole place for imagining life but I
guess the the the counter that has been
that okay yes the surface is a
horrendous place to imagine life
thriving um but as you go up in altitude
the very dense atmosphere means that
there is a cloud layer um where the
temperature and the pressure become
actually fairly similar to the surface
of the Earth and so maybe there are
microbes stirring around in the clouds
which are producing phosphine um at the
moment this is fascinating it's got a
lot of us reinvigorated about the
prospects of going back to Venus and
doing another Miss Mission there in fact
there's now two NASA missions Veritas
and da Vinci which are going to be going
back in before 2030 or the
2030s um and then we have a European
Mission I think that's slated now and
even a Chinese Mission might be coming
along the way as well so we might have
multiple missions going to Venus which
has long been overlooked I mean apart
from the Soviets there really has been
very little in the way of exploration of
Venus as certainly as compared to Mars
Mars has enjoyed most of the activity
from NASA's Rovers and surveys
um and Mars is certainly fascinating
there's you know this signature of
methane that has been seen there before
um again there the discussion is whether
that methane is a product of biology
which is possible something that happens
on the earth or whether it's some
geological process that we are yet to
fully understand could be you know for
example a reservoir of methane that's
trapped under the surface and it's
leaking out seasonally so the nice thing
about Venus is if there is a giant
living civiliz there it'll be airborne
so you can just fly through and collect
samples yeah with Mars and uh moons of
uh Saturn and Jupiter you're going to
have to dig dig under to find the
civilizations dead or living right and
so yeah maybe it's easier than for Venus
because certainly you can imagine just a
balloon floating through the atmosphere
um that or a drone or something that
would have the capability of just
scooping up and sampling um to to dig
under the surface of Mars is
maybe feasible is with you know
especially with something like Starship
that could launch you know a huge Digger
basically to the surface and you could
just excavate away at the surface but
for something like Europa um we really
are still unclear about how thick the
ice layer is um how you would melt
through that huge thick layer to get to
the ocean and then potentially also
discussions about contamination the
problem with looking for life in the
solar system which is different from
looking for life with exoplanets is that
you always run the risk of especially if
you visit there of introducing the life
yourself right it's very difficult to
completely exterminate every single
microbe and Spore on the surface of your
of your Rover or the surface of your
Lander and so there's always a risk of
introducing something I mean to some
extent there is continuous exchange of
material between these plets naturally
on top of that as well and now we're
sort of accelerating that process to
some degree
um and so if you dig into europa's
surface which probably is completely
pristine it's very unlikely there has
been much exchange with the outside
world for for its subsurface ocean You
Are For the First Time potentially
introducing bacterial spores into that
environment that may compete or may
introduce spous signatures for the life
you're looking for and so it's it's
almost an ethical question as to how to
proceed with looking for life on on
those subsurface oceans and I I don't
think one we've really have a good
resolution for at this point ethical so
you mean ethical in terms of concern for
the like for preserving life elsewhere
like not to murder it as opposed to the
scientific one I mean we always worry
about a space virus right coming coming
here or or you know some kind of
external source and we would be the
source of that potential contamination
or the other direction yeah I mean they
that you know the whatever whatever
survives in such harsh conditions be
pretty good at uh surviving in all
conditions it might be a little bit more
resilient and robust so it might
actually take a ride on us back home
possibly I mean I'm sure I'm sure that
some people would be concerned about
that I think we would we would hopefully
have some containment uh procedures as
if if we did sample return or you mean
you don't even really need a sample
return these days you can pretty much
send like a little micro laboratory to
the planet to do all the experiments in
you know in situ and then just send them
back to your planet the data and so I
don't think this is necessary that
especially for a case like that where
you might have contamination concerns
that you have to bring samples back um
although probably if you brought back
europan Sushi it would probably sell for
quite a bit with the billionaires in New
York
City Sushi yeah um I would love from an
engineering perspective just to see all
the different candidates and designs for
like the scooper for Venus and the
scooper for Europa and and Mars I
haven't really look deeply into how they
actually like the actual engineering of
collecting assembles because that's the
engineering of that is probably
essential for not either destroying life
or or polluting it with our own microbes
and so on so that that's like an
interesting engineering challenge I
usually for Rovers and Stu focus on the
on the robot on the sort of the mobility
aspect of it on the robotics the
perception and the movement and the
planning and the control but there's
probably the scooper is probably where
the action is
the microscopic sample collection so
basically you have to first clean your
vehicle make sure it doesn't have any
earthlike things on it and then you have
to put it into some kind of thing that's
perfectly sealed from the environment so
if we bring it back or we analyze it
it's not um it's not going to bring
anything else external in yeah I don't
know it it's be that would be an
interesting engineering design there
yeah I mean CES has been uh leaving
these little pods on the surface quite
recently there's some neat photos you
can find online and it's they kind of
look like a lightsaber hilts which so um
that yeah to me I I think I tweeted
something like uh you know this weapon
is your life like don't lose at
curiosity because it's just dumping
these little vials everywhere and it's
yeah it is scooping up these things and
the intention is that in the future um
there will be a sample return mission
that will come and pick these up um but
it's I mean the engineering behind those
things is so impressive the thing that
blows me away the most has been the land
land ings um especially I'm training to
be a pilot at the moment so that's the
sort of you know watching Landings has
become like my pet hobby on YouTube at
the moment and how not to do it how to
do it with different levels of uh
conditions and things but with the you
know when when you think about landing
on Mars Just the light travel time
effect means that there's no possibility
of a human controlling that descent and
so you have to put all of your faith and
your trust in the computer code or the
AI or whatever it is that you've put on
board that thing to to make the correct
descent um and so there's this famous
period called seven minutes of hell
where you're basically waiting for that
light travel time to come back to know
whether your vehicle successfully landed
on the surface of not and during that
period you know in your mind
simultaneously that it is doing these
multi-stages of um deploying its
parachute deploying the crane activating
its Jets to come down and controlling
its descent to the surface um and then
the crane has to fly away so it doesn't
AC hit the Rover and so there's a series
of uh multi-stage points where any any
of them go wrong you know the whole
mission could could go AR um and so the
fact that we are fairly consistently
able to build these machines that can do
this autonomously is to me one of the
most impressive acts of engineering that
NASA have achieved yes the unfortunate
fact about physics is the takeoff is
easier than the
landing and you mentioned Starship one
of of the incredible engineering Feats
that you get to see is the reusable
rockets that take off but they land and
they land uh using control and they do
so perfectly and sometimes when it's
synchronous it's it's just it's
beautiful to see and then with Starship
you see the the Chopsticks that catch
the ship I mean there's just so much
incredible engineering but you mentioned
uh Starships is somehow helpful here so
what's your hope with Starship what kind
of science might it enable Poss
there's two things I mean it's the
launch cost itself which is hopefully
going to mean per kilogram is going to
dramatically reduce the cost of it the
sort of the even if it's a factor of 10
higher than what Elon originally
promised this is going to be a
revolution for the cost to launch that
means you could do all sorts of things
you could launch um large telescopes
which could be basically like jwst but
you don't even have to fold them up jwst
had this whole issue with a design that
it's 6 and 1 half meters across and so
you have to there's no fuselage which is
that large at the time the Aries 4
wasn't large enough for that and so they
had to fold it up into this kind of
complicated origami and so a large part
of the cost was figuring out how to fold
it up testing that it unfolded correctly
repeated testing and you know there was
something like 130 fail points or
something during this unfolding
mechanism and so all of us were holding
our breath during that process but if
you have the ability to Just Launch you
know arbitrarily large masses um at
least comparatively compared to jbst and
very large mirrors into space you can
more or less repurpose groundbased
mirrors um the hubo Space Telescope
mirror and the jbst mirrors are designed
to be extremely lightweight and that
increased their cost significantly um
they have this kind of honeycomb design
on the back to try and minimize the the
weight if you don't really care about
weight because it's so cheap then you
could just literally grab many of the
existing groundbased mirrors across tesk
across the world four meter 5 meter
mirrors and just pretty much attach them
to a chassis and have your own
space-based telescope um I think the
Breakthrough foundation for instance uh
is an entity that has been interested in
doing this sort of thing um and so that
raises the prospects of having not just
one wst that just you know deris is a
fantastic resource but it's split
between all of us cosmologists star
formation uh astronomers those of us
studying exop plants those of us wanting
to study you know the ultra deep fields
and the origin of the first galaxies the
expansion R of the universe everyone has
to share this resource but we could
potentially each have you know one uh
jwst each that is uh maybe just studying
a handful of the brightest exoplanet
stars and measuring their atmospheres
this is important because if you we
talked about this planet trapis 1e
earlier that planet if Jud sted it and
tried to look for Bio signatures by
which I mean oxygen um nitrous oxide
methane it would take it of order of 200
transits to get even a very marginal
what we call 2 a half Sigma detection of
those which basically nobody would
believe with with that and 100 transits
I mean this thing transits once every
six days so you talking about sort of
four years of staring at the same star
with one telescope there'd be some
breaks but it'd be hard to schedule much
else because you have to continuously
catch each one of these transits to
build up your signal to noise and so JC
is never going to do that in principle
technically J could technically have the
capability of just about detecting a bio
signature on an earthlike planet around
around a nons sunlike star but still
impressively we have basically the
technology to do that but we simply
cannot dedicate all of its time
practically to that one resource and so
Starship opens up opportunities like
that of mass producing these kinds of
telescopes which will allow us to survey
for life in the universe which of course
is one of the grand goals of astronomy I
wonder if you can speak to the the
bureaucracy the political battles the
scientific battles for for time on the
James web
telescope is there there must be a
fascinating it's process of scheduling
that all scientists are trying to
collaborate and figure out what the most
important problems are and there's an
interesting network of interfering
scientific experiments probably they
have to somehow optimize over it's it's
a very difficult process I don't envy
the TAC that are going to have to make
this decision we call it the TAC the
time allocation committee that that make
this decision um and I've served on
these before and it's very difficult I
mean typically for Hubble we we were
seeing at least 10 sometimes 20 times
the number of proposals for telescope
time versus available telescope time for
J there has been one call already that
has gone out we called it cycle one and
that was over subscribed by I think
something like 6:1 7:1 and uh the cycle
2 which has just been announced uh
fairly recently and the deadline is
actually the end of this month so my
team totally layser focused on running
our proposals right now um that is
expected to be much more competitive
probably more comparable to what Hubble
saw and so it's hard more competitive
than the cycle one you said already
that's already more competive than the
first cycle so I said the first cycle of
James web was about 6 to1 um and this
will probably more like 20 to1 I would
expect so these are all proposals by
scientists and so on and it's not like
you can schedule at any time cuz if
you're looking for transit times yeah
you have you have a a Time critical
element yes time critical element and
they're conflicting in non like non
obvious ways because the the the
frequency is different the the duration
is different there's there's probably
computational needs that are different
uh the there's the type of sensors the
direction pointing all that yeah it it's
hard and there were certain programs
like doing a deep field study where you
just more or less point the telescope
and that's pretty open I mean you're
just accumulating photons you can just
point at that that patch of the sky um
whenever the telescope is not doing
anything else and just get to your month
let's say a month of integration time is
your is your goal over the lifetime jst
so that's maybe a little bit easier to
schedule it's harder especially for us
looking at cool worlds um because as I
said earlier these these plants Transit
very infrequently MH so we have to wait
if you're looking at the Earth
transiting the Sun an alien watching us
they they would only get one opportunity
per year to do that observation the
transit lasts for about 12 hours um and
so if they don't get that time it's hard
you that's it if it conflicted with
another proposal that wants to do use
the another time critical element it's
much easier for plants like uh these hot
these hot plants or these close-in
plants um because they Transit so
frequently there's may be a 100
opportunities and so then the tat can
say okay they want 10 transits there's
100 opportunities here it's easier for
us to give us time give them time um
we're almost in the worst case scenario
we're proposing to forx Moes around two
cool planets and so we really only have
one bite of the Cherry for each one and
so our sales pitch has been that these
are extremely precious events and more
importantly
jdst is the only telescope the only
machine Humanity has ever constructed
which is capable of finding moons akin
to the moons in our solar system kepa
can't do it even Hubble can't do it J is
the first one and so there is a new
window to the universe because we know
these moons exist they they're all over
the place in the solar system you have
the moon you have IO Kalisto Europa
ganime Titan lots of moons of Fairly
similar size s of 30% the size of the
Earth and this telescope is the first
one that can find them um and so we're
very excited about the profound
implications of ultimately solving this
journey we're on in astronomy which is
to understand our uniqueness we want to
understand how common is the solar
system are we the way are we the
architecture that frequently emerges
naturally or is there something special
about what happened here I think this is
not the worst case the best case it's
obvious it's super rare so you have to
like I would if so I'm I love scheduling
from a computer science perspective
that's my background so algorithmically
to solve a schedule problem I would
schedule the rarest things first and
obviously this is the the jwst is the
first thing that can actually detect a
cool world world so this is a big new
thing you can show off that new thing
happens rarely schedule it first it's
perfect you should be in the T this is
perfect I will I'll file my application
after we're done with this I I you know
this part of me is the OCD part of me is
the computational aspect I love
scheduling uh Computing device because
you have that kind of scheduling on
supercomputers on that scheduling
problem is fascinating how do you
prioritize computation how you
prioritize science uh data collection uh
sample collection all that kind of stuff
stuff it's actually kind of it's kind of
fascinating because data in ways you
expect and don't expect will unlock a
lot of solutions to uh some fascinating
Mysteries and so collecting the data and
doing so in a way that maximize the
possibility of Discovery is really
interesting like from a computational
perspective I agree there's there's a
real satisfaction in extracting the
maximum science per unit time yeah
exactly out of your telescope and that's
that's the tax job um but the the T are
not machines they're not a piece of
computer code um they will make their
selections based off human judgment and
um a lot of the telescope certainly
within the field of exoplanets because
there's different fields of astronomy
but within the field of exoplanets I
think a good expectation is that most of
the telescope time that jwc have will go
towards atmospheric retrieval which is
uh sort of alluded to earlier you know
like detecting molecules in the
atmospheres not bio signatures CU as I
said it's really not designed to do that
it's pushing Jus T probably too far to
expect to do that but it could detect
for example a carbon dioxide Rich
atmosphere on trapis one that's not a bi
signature but you could prove it's like
a Venus in that case or maybe like a
Mars in that case like both those have
carbon dioxide Rich atmospheres doesn't
prove or disprove the existence of life
either way but it is our first
characterization of the nature of those
atmospheres maybe we can even tell the
pressure level and the temperature of
those atmospheres so that's very
exciting but um there's we we are
competing with that and that I I think
that science is completely mind-blowing
and fantastic we have a completely
different objective which is in our case
to try and look for the first evidence
of these small moons around these
planets um potentially even moons which
could be habitable of course so I think
it's a very exciting goal but um attack
has to make a human judgment essentially
about which science are they most
excited by which one has the highest
promise of return the most highest
chance of return and so that's hard
because if you look at a planetary
atmosphere well you know most of the
time the planet has an atmosphere
already and so there's almost a
guaranteed success that you're going to
learn something about the Atmosphere by
pointing J at it whereas in our case
there's a harder cell we are looking for
something that we do not know for sure
exists yet or not and so we are pushing
the telescope to do something which is
inherently more risky yeah but the
existence if shown already gives a
deep lesson about what's out there in
the universe that means that other stars
have similar types of variety as we have
in our solar system they have an IO they
have a Europa and so on which means like
there's a lot of possibility for Icy
planets for water for planets that
enable planets and moons that I mean
that that's super exciting because that
that means everywhere through our galaxy
and Beyond
there is just innumerable possibility
for weird creatures I agree life fors
you don't have to convince me I mean
NASA NASA has been on this quest for a
long time and it's sometimes called eer
Earth it's the frequency of Earth like
usually they say planets in the universe
how common are planets similar to our
Earth in terms of um ultimately we'd
like to know everything about these
plets in terms of the amount of water
they have how much atmosphere they have
but for now it's kind of focused just on
the size and the distance from the Star
essentially how how often do you get
similar conditions to that um that was
kep's primary Mission and it really just
kind of flirted with the answer didn't
quite get to a definitive answer but I
always say look if we're looking if if
that's our primary goal to look for
earthlike I would say worlds then moons
has to be a part of that because we know
that um Earth likee and from the capit
DAT to the preliminar is that earthlike
planets around sunlike stars is not an
inevitable outcome it seems to be
something like a 1 to 10% outcome so
it's not particularly inevitable that
that happens but we do often see about
half of all sunlike stars have either a
mini Neptune a Neptune or a Jupiter in
habital Zone Of Their Stars that's a
very very common occurrence that we see
yet we have no idea how often they have
moons around them which could also be
habitable and so there may very well be
if if even one in five of them has an
earth like moon or even a Mars like Moon
around them then there would be more
habitable real estate in terms of
exomoons than exoplanets in the universe
you can essentially 2x 3x 5x maybe 10x
the number of Hab habitable worlds out
there in the universe our current
estimate for like the Drake equation
absolutely so this this is a one way to
increase the
confidence and increase the the value of
that parameter and just know where to
look I mean we we would like to know
where should we listen for technos
signatures where should we be looking
for Bio signatures um and not only that
but what role does the does the moon
have in terms of its influence on the
planet um we talked about these directly
imaged telescopes earlier these missions
that want to take a photo to quote car
Sean the pale blue dot of our planet but
the pale blue dot of an exoplanet and
that's the dream to one day capture that
but as impressive as the resolution is
that we are planning and conspiring to
design for the future generation
telescopes to achieve that even those
telescopes will not have the capability
of resolving the Earth and the moon
within that it'll be a pale blue dot
pixel but the moon's gray grayness will
be intermixed with that pixel and so
this is a big problem because one of the
ways that we are claiming to look for
life in the universe is a chemical
disequilibrium so you see two molecules
that just shouldn't be there they
normally react with each other or even
one molecule that's just too reactive to
be hang around the Atmosphere by itself
so if you had um oxygen and methane
hanging out together those would
normally react fairly easily and so if
you detected those two molecules in your
pale blue dot Spectra you be like okay
we we have evidence for life something's
metabolizing on this planet um however
the challenge here is what if that moon
was Titan Titan has a methane Rich
atmosphere and what if the pale blue dot
was in fact a plant devoid of life but
it had oxygen because of water
undergoing this photolysis reaction
splitting into oxygen hydrogen
separately so then you have all of the
uh Hallmarks of what we would claim to
be life mhm but all along you were
tricked it was just a moon that was
deceiving you and so we are never going
to we're never going to I would claim
really understand the or or complete
this quest of looking for Life by a
signatures in the universe unless we
have a deep knowledge of the prevalence
and role that moons have they may even
affect the habitability of the planets
themselves of course our moon is
freakishly large by mass ratio it's the
largest moon in the solar system it's a
1% Mass Moon if you look at Jupiter's
moons they're like 10^ minus 4 much
smaller and so our own moon seems to
stabilize the obliquity of our planet it
gives rise to Tides especially early on
when the moon was closer those Tides
would have covered entire continents and
those those Rock pools that would have
been scattered across the entire plateau
may have been the origin of Life on our
planet the moon forming impact may have
stripped a significant fractional
lithosphere of the earth which without
it plate tectonics may not have been
possible we would have had a stagnant
lid because there was just too much
lithosphere stuck on the top of the of
the planet and so there are speculative
reasons but intriguing reasons as to why
a large Moon may be not just important
but Central to the question of having
the conditions necessary for life so
moons can be habitable in their own
right but they can also play significant
influence on the habitability of the
planets they orbit and further they will
surely interfere with our attempts to
detect life remotely from
AAR so uh taking a tangent upon a
tangent uh you've written about uh
binary planets what what's and that
they're surprisingly
common or they might be surprisingly
common what's the difference between a
large Moon and binary planets what what
are binary planets what uh what's
interesting to say here about giant
rocks flying to space and orbiting each
other the thing that's interesting about
binary objects is that they're very
common in the universe binary stars are
everywhere fact the majority of stars
seem to live in binary systems um when
we look at the outer edges of the solar
system we see binary Kyer Bel objects
all the time asteroids Bally bound to
one another Pluto Sharon is kind of an
example of that it's a 10% Mass ratio
system it almost is by many definitions
a binary Planet but now it's a dwarf
planet so yeah I don't know what you
call that now but we we know that these
you know the universe likes to make
things in pairs yeah um so you're saying
our sun is an
incel it's it's looking so most things
are dating they're in relationships and
our ours is alone it it's not a complete
free of the universe to be alone but it
is um it's more common for sunl stars if
you count up all the sunl stars in the
universe about half of the sunlike star
systems are in binary or trinary systems
and the other half are single but
because those binaries are two or three
stars then cumulatively maybe like a
third of all sunic stars are single I'm
trying hard to not anthropomorphize the
relationship the star with each other
triplet the triplet yeah that's yeah
I've met those folks also um so is there
something interesting to learn about the
habitability the how that affects the
probability of habitable worlds when
they kind of couple up like that in
those different ways well it depends
when we're talking about the stars of
the planet certainly if Stars couple up
that has a big influence on the
habitability um of course this is very
famous from Star Wars Tatooine in Star
Wars there's a binary star system and
you have Luke Skywalker looking at the
sunset and seeing two stars come down
and uh for years we thought that was
purely a product of George Lucas's
incredibly creative mind and we didn't
think that planets would exist around
binary star systems it seems like too
tumultuous an environment for a
quiescent planetry disc circumstellar
disc to form planets from and yet uh one
of the astounding discoveries from
Kepler was that these appear to be quite
common in fact as far as we can tell uh
they're just as common around binary
stars as single Stars the only uh caveat
to that is that you don't get plants
close into binary Stars they have like a
clearance region in on the inside where
plants maybe they form there but they
they don't last they are dynamically
unstable in that zone but once you get
out to about the distance of the Earth
orbits the Sun or even a little bit
closer in you start to find plants
emerging and so that's the right
distance for liquid water it's the right
distance for potentially life on those
plants and so there may very well be
plenty of habital plants around the
binary Stars binary plants is a little
bit different um binary plants I don't
think we have um any serious connection
of plant binarity to habitability
certainly when we investigated it that
wasn't our drive that this is somehow
the solution to life in the universe or
anything it was really just a like all
good science questions a curiosity
driven question what's the dynamic are
they legit orbiting each other as they
orbit this uh the star so the formation
mechanism proposed here um because it is
very difficult to form two Proto plets
close to each other like this they were
generally merged within the dis and so
that's why you normally get single
planets but you could have something
like Jupiter and Saturn form at separate
distances they could dynamically be
scattered in towards one another and
basically not quite Collide but have a
very close on encounter now because uh
tidal forces increase dramatically as
the distance decreases between two
objects the tides can actually dissipate
the kinetic energy and bring them bound
into one another so that seemed when we
you know when you first hear that you
think well that seems fairly contrived
that you'd have the conditions just
right to get these ties to cause a
capture but numerical simulations have
shown that about 10% of planet planet
encounters are shown to produce
something like bino planets which is a
startling prediction um and so that
seems at odds with naively the exoplanet
catalog for which we know of so far no
binary planets and we proposed one of
the resolutions to this might be that
the bin planets are just incredibly
difficult to detect which is also
counterintuitive because remember how
they form is through this tidal
mechanism and so they form extremely
close to each other sort of the distance
that iio is away from Jupiter just a few
planetry radi they're almost touching
one another and they're just tily locked
facing each other for eternity and so in
that configuration as it transits across
the star it kind of looks like you can't
really resolve there two planets it just
looks like one planet to you that's
going across the the star the temporal
resolution of the data is rarely good
enough to distinguish that and so you'd
see one Transit but in fact it's two
planets very close together which are
transiting at once and so yeah we wrote
a paper just recently where we developed
um some techniques to try and get around
this problem and hopefully provide a
tool where we could finally look for
these planets the problem of detection
of these planets when they're so close
that was our Focus was how do you how do
you get around this this merging problem
so whether there are or not uh we don't
know we we're planning to do a search
for them but um it it remains an open
question and I think just one of those
fun astrophysics Curiosities questions
whether binary planets exist in the
universe because then you know you have
binary Earths you could have binary
Neptune all sorts of wild stuff that
would you know float to the Sci-Fi
imagination I wonder what the physics on
a binary Planet feels like it might be
trivial I have to think about that I
wonder if there's some interesting
Dynamics like it feel multiple or or
would gravity feel different at
different parts of the the surface of
the sphere when there's another large
sphere that's I would think that the
force would be U fairly similar because
the shape of the object would deform to
a flat geop potential essentially
uniform geop potential but it would lead
to a distorted shape for the two objects
I think they would become ellipsoids
facing one another um so it would be
pretty wild when you you know people
like Flat Earth or spherical Earth you
fly from space and you see a football
shaped Earth it's your own Planet
finally there's proof and I wonder how
how difficult it would be to travel from
one to the other cuz you have to
overcome the
well no it might be kind of easy yeah I
mean they're so close to each other that
helps and I think the most critical
Factor would be how massive is the
planet that's always I mean one of the
challenges with escaping planets there
was a a fun paper one of my colleagues
wrote that suggested that superar
planets may be inescapable mhm if you
were a civilization that were born on a
superar the surface gravity is so high
that the chemical potential energy of
hydrogen or or methane whatever fuel
you're using simply um is at odds with
the with the gravity of the planet
itself and so you would uh you know our
current Rockets I'm not sure the
fraction but maybe like 90% of the
rocket is fuel or something by mass
these things would have to be um like
the size of the the Giza Pyramids of
fuel with just a tiny tip on the top in
order just to escape their plan planetry
atmosphere and so it has been argued
that if you live on a super
Earth you may be you may be forced to
live there forever there may be no
Escape unless you invent a space
elevator or