my love for the night sky began a long
time ago I grew up in the tiny rural
farming town of B branch Arkansas
official population 63 not kidding but
while my small hometown might not have
had much of a social scene the night sky
was breathtaking I spent much of my
childhood lying on blankets out in the
field behind my mom and dad’s house
and asking my parents questions about
the Stars about how the universe worked
about what lies beyond what we can see
and my parents weren’t scientists and
these were the days before the internet
but I remember one day I asked my mom
some outlandish question about the
universe and she looked at me and she
said I don’t know the answer to that
question but one day you can figure it
out and that’s really what set me on my
path to becoming an astronomer and of
course I’m not alone in my love for the
night sky for centuries human beings
have been captivated by the night sky a
dark sky full of stars has always been a
standing invitation to ask big questions
and these questions go beyond just being
scientific questions they’re questions
that get to the heart of what it means
to be a human being where do we come
from how do we get here are we alone and
there’s so much we can learn about
astronomy just from simply looking up at
the night sky our ancestors learned
about the way the world works from
watching how the constellations would
appear and reappear over the course of
the year the very first astronomers
noticed that some of the brightest stars
in the sky moved in a different way than
most of the stars and of course those
turned out to be planet
in our solar system at that time it was
assumed that earth our fragile blue
planet was the center of it all that all
the other celestial bodies revolved
around the earths and then one day a
little over 400 years ago Galileo took
his telescope which was originally
intended to watch ships coming over the
horizon and pointed it to the sky and
everything changed that simple act
shifted the paradigm of how we view the
universe and ultimately how we view
ourselves of course what Galileo
discovered was that Jupiter had moons
that were orbiting around it that means
they weren’t orbiting around the earth
that means the earth wasn’t the center
of the universe
GameChanger and since that time of
course our telescopes have gotten bigger
and better as an astronomer I’ve been
really lucky to have observed some of
the world’s biggest telescopes and Chile
and Hawaii we put our biggest telescopes
on the ground
Anto mountains so that we can try to get
above the Earth’s atmosphere which
serves to blur and obscure the celestial
objects that we’re trying to look at but
even on the tallest mountains we still
have to deal with the atmosphere now
we’ve found really cool ways to
counteract some of the blurring effects
of the Earth’s atmosphere but we still
have to deal with the fact that the
atmosphere is there and our Earth’s
atmosphere completely obstructs some
wavelengths of light completely now
that’s good for life on Earth
not so good for astronomers who want to
view their objects in all the
wavelengths of light so what do we do we
put telescopes in space and of course of
all the telescopes the space telescopes
the Hubble Space Telescope is the
world’s most famous Hubble has now been
in space for a little over 26 years it
celebrates its 27 year birthday that
here Hubble has become so much more than
a scientific tool it’s become an
inspiration for the world it’s become a
pop culture icon you can find Hubble
images everywhere in TV and films as
music album art on the sides of u-haul
trucks ask anyone in the world to name a
telescope and they’re probably going to
say Hubble the beauty of Hubble’s images
have captivated the world but it’s not
really straightforward why that is why
don’t we find beauty in Hubble’s images
it’s natural that we find beauty in
images like sunsets or oceans or
mountains those things are all part of
our everyday experience as human beings
but nebulae aren’t why do we find these
how it it’s beautiful I’m not sure that
I know the answer to that question but I
think part of the reason might be that
we know that on a deep level that we’re
connected to the cosmos we know that
when we look up at the heavens that in a
sense we’re looking back at ourselves
back at our origins the iron in our
blood and the calcium in your bones was
literally forged inside of a star that
ended its life and grand fashion is a
supernova we’re connected viscerally to
the universe hubble’s images also
transcend languages national borders
their beauty is universal Hubble’s
images that have also told us that were
connected to each other of all these
beautiful Hubble images that we’ve
gotten in over the past 27 years if I
had to pick a personal favorite this
would be it this is the Hubble Ultra
Deep Field this image came out when I
was in graduate school so that’s another
reason it’s sort of special to me I did
a lot of my dissertation research on
this image but for a bigger reason than
just that this image has changed the way
we understand the universe so you go
outside tonight look up at the stars
every star that
you see in the sky is part of our home
galaxy the Milky Way but for this image
Hubble stared past the Milky Way into
this tiny little dark piece of sky so
that’s like looking at the universe
through a straw if you held out your
pinky finger you could cover up this
image and in this image Hubble sees
10,000 galaxies every single point of
light in this image except for just a
few grand foreground stars is an
individual galaxy containing billions of
stars and so just imagine take this
little tiny patch of sky multiply it by
the huge number of times you would need
to fill up the entire sky what Hubble
has shown us is that there are hundreds
of billions of other galaxies outside of
our Milky Way Hubble has given us the
size of the universe but is amazing as
Hubble is as wonderful it’s as it’s been
as much as it’s taught us over the past
27 years there are some ways that we’ve
pushed Hubble to its limits and in deep
images like this like the Hubble Ultra
Deep Field at some point we come to the
edge of what we can see and so we need a
new different more powerful telescope
that will help us see beyond that edge
and learn amazing new things about the
universe and so at NASA we are working
on the scientific successor to Hubble
the James Webb Space Telescope this
telescope is designed to answer the
biggest questions in astronomy today
those questions that how will just can’t
quite get you and I truly believe that
the Webb telescope will be a worthy
successor to the Hubble so Webb is
different from Hubble in a few key ways
and the first is the size so Webb is big
really big Webb will be by far the
biggest telescope we’ve ever sent to
space Hubble is about the size of a
school bus top-to-bottom Webb stands
over three stories tall
all and as wide as a tennis court the
second big difference between Webb and
Hubbell is the place in space that Webb
will be Hubble orbits the earth about
350 miles up relatively close we’re
going to put Webb out a million miles
from Earth
that’s about four times further away
than the moon we put Webb in this part
of space so it can get really cold and
that leads to the third key difference
between Hubble and Webb which is the
type of light that Webb will see Hubble
is primarily a visible light telescope
it sees the universe primarily an
optical light that your eyes can see
Webb will see the universe in a whole
new light an infrared light infrared
light is just a little bit more red than
what your eyes can see and Hubble has a
little tiny bit of capability in the
near-infrared and this image shows a
tantalizing hint of what we might be
able to see with Webb so with all of
these new technologies we hope to learn
a few key things about the universe the
first thing we want to find is the very
first galaxies that were born after the
Big Bang telescopes are time machines
they literally allow us to see objects
as they were in the past as we use our
telescopes to look at objects that are
further away in space the light from
those objects takes time to travel
through space to reach our telescopes in
the further back we look in distance the
further back we’re looking in time and
so with Hubble we’ve been able to push
back and see distant galaxies but we
have yet to see the very first galaxies
that were born after the Big Bang so
we’re talking about looking back in time
over 13 and a half billion years we have
computer simulations that show us what
we think that part of the universe might
look like but there are no telescopes
right now in space or on the ground that
are powerful enough to observe this part
of the universe and with Webb we hope to
see these infant galaxies another big
key goal of Webb is to learn how
galaxies grow over time
so we want to see how those infant
galaxies grow up to be the grown-up
galaxies that we see in the nearby
universe today so the distant galaxies
are much different than galaxies in the
nearby universe
and how that whole process happens is
still a big mystery to astronomers and
so with Webb we hope to be able to learn
a lot more about that process in a new
way
the third key thing we want to learn
with Webb is about how stars are born so
stars are the building blocks of
galaxies but there’s a lot about their
formation that we just don’t know and
that’s because stars are born inside
dusty cocoons and we can’t see the sites
of the star formation at least in
visible light infrared light has the
really great property that it’s able to
peer through dust to see the stars
inside being born and in addition to
stars we plan to study planets both
planets within our solar system and
planets outside our solar system
exoplanets now is when I was a kid we
only knew of the planets inside our own
solar system
now today thanks to telescopes like
NASA’s Kepler telescope we know that the
universe is literally teeming with
planets go outside at night point up at
a star and chances are there’s at least
one planet orbiting that star that’s a
complete paradigm shift Kepler has shown
us that these star and planet systems
come in an incredible variety in
combinations that we had never imagined
before the Kepler telescope finds these
planets by staring at a star watching
for the light in the star to dip down
which means a planet has passed in front
a transit so that’s how Kepler has found
all these planets but with web we want
to go one step further we want to watch
the Starlight is it filters through the
atmosphere and learn about the chemical
components of those atmosphere
we want to be able to find chemicals
like water vapor carbon dioxide methane
the chemicals that would signal
habitability now this is really really
hard in this image demonstrates why this
is an actual image from one of NASA’s
solar observatories of the transit of
Venus that happened a few years ago now
if you squint you can almost see the
tiny little atmosphere that Venus has
stars are bright planets are tiny and
their atmospheres are minuscule we need
incredibly advanced technology to be
able to look in detail at these
atmospheres but with web we have it so
even with all of that technology we
would really need a planet system that
was relatively nearby had the planets
that were the right distance from the
star all the right things to line up to
find a potentially habitable planet Airy
system we require a lot of look but
sometimes nature delivers just a few
weeks ago we got new observations of the
Trappist one planet system which is a
mere 40 light years away our cosmic
backyard these new observations tell us
that three of these seven planets likely
lie in the habitable zone now we don’t
know anything about these planets we
don’t know if they have atmospheres or
if they would be hospitable to life but
with web we intend to look and the great
news is that after two decades of hard
work we are almost finished building
this incredible machine the iconic gold
mirrors of the Webb telescope were one
of the first technologies that we
started working on the whole mirror put
together is about 21 feet wide and it’s
coated in an incredibly thin layer of
gold because gold is highly reflective
in infrared light the mirrors are also
incredible
precise if you were to stretch out that
21-foot mirror to be the size of the
continental US the biggest bumps and
valleys would only be a few inches this
is incredibly difficult engineering and
this is the first time a mirror like
this has ever been sent to space just
last year we finished assembling this
giant mirror so much work has gone on to
get us to this place the other iconic
part of a telescope and the biggest
structure on the telescope is the giant
Sun shield so this is a five layer sun
shield that protects the mirrors and the
instruments from the light and the heat
of the Sun of course all these elements
require extensive testing and testing
has been going on for pretty much since
the start of the whole program all
elements are tested if their individual
levels and then as bigger systems in
fact if you go to our website on our
homepage you can watch a live webcam of
some of this testing going on right now
at NASA’s Goddard Space Flight Center in
just a couple months we’ll shift the
mirrors and the instruments down to
Johnson Space Center in Houston where it
will undergo extreme cryogenic testing
in the giant chamber a which is the
chamber that was used to test the Apollo
era spacecraft old meets new history
meets the future and oh by the way we
have a really intricate deployment
sequence that we have to do with this
telescope so launch is only the
beginning once it gets into space it has
to unfold and this whole process takes
about two weeks now today we can take
Plato’s words more literally today right
now NASA is building the rockets and the
capsules that will take human beings to
Mars today we’re dreaming and building
the telescopes web and it’s successors
that will ultimately find life elsewhere
than our pale blue dot astronomy in this
deep drive to explore is what drives us
towards these missions the reason
we build these missions is because of
the promise of discovery it’s the
promise of hundreds of billions of
planets in hundreds of billions of
galaxies and countless untold surprises
waiting to be discovered
thank you [Applause]