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every new telescope put up in space has
always found something they didn't
expect something new
the james webb space telescope is the
biggest most complex telescope that nasa
has ever launched into space
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telescopes are time machines
webb will push us back into the realm of
the very first stars and galaxies in the
universe
the webb telescope is designed to see as
far back in time as we can possibly see
luminous objects when the universe was
maybe 100 million years
old we have a suite of very powerful
instruments to study the atmospheres of
planets
webb will be very helpful to us in the
search for life in the future
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up until hubble flew we were using
telescopes on the ground and they
couldn't see very far t-minus six
five four
three
two
one
and liftoff of the hubble space
telescope our window on the universe
when hubble flew we knew that it was
going to be able to reach out further
into the universe but we didn't really
have any idea what was out there
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the hubble deep field image was a
discovery image of the 90s
what was unique about this was the idea
of spending days and days of valuable
hubble time staring at a tiny spot in
the sky where there was nothing
when we did a deep image like this
astronomers suddenly saw that there was
a richness of galaxies in there
thousands and thousands of galaxies we'd
never seen before
basically a history of the whole
universe in one image
the universe is 13
800 million years old
light travels very rapidly but the
distances are so huge
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hubble can see in the visible and
ultraviolet with a little schmidt
in the infrared but the things that we
want to see now the first stars that
turned on in the universe of the first
galaxies they were probably very bright
objects that emitted a lot of
ultraviolet light
but that ultraviolet light with a very
short wavelength as it traverses through
a universe that's been expanding for
about
13.5 billion years gets stretched out so
by time it reaches us
it's no longer ultraviolet it's infrared
after they had the hubble deep field
they said we can't see far enough
so we need a bigger telescope that's
more sensitive and that can look at
longer infrared wavelengths
so that we can see the more distant
universe
about
13.7 billion years ago there were no
stars in the universe
there was just gas and dark matter
we'd gone through 200 million years of
dark ages suddenly the first stars and
galaxies start popping up all over the
place
cosmic sunrise
and so that's what jwst is for mapping
the first billion years of galaxy
formation and growth in the universe
the webb telescope is the first
general purpose powerful infrared
telescope we've ever had
it opens up what i call the infrared
treasure chest if you were a bumblebee
at the distance of the moon away from
the telescope we would be able to pick
up the heat that you send out
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infrared is special for astronomers
because cooler objects that cannot emit
visible light are able to emit infrared
when we look at the universe you see
there's lots of sort of dusty dark areas
but one of the great things about the
infrared is light can travel through the
dust
the dust becomes almost transparent
so if we're trying to see how stars and
planets form in their early times the
infrared is the place to be
if you want to see dim stars you don't
stay in the city you go out to the
country right you get away from the
lights
we want to see the dimmest galaxies
there are to see
well the earth is pretty bright and
infrared
so you want to get away from the earth
you want to get away from the moon
webb needed to be far away from earth
and it needed to be very cold if it's
going to work in the infrared
so if you cool the whole telescope down
near the temperature of space then you
can see
out with incredible clarity over the
first billion years of the universe
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so we're going to a point called the sun
earth l2 point it's a million miles away
from the earth on the opposite side of
the sun
and it's a place where the gravity of
the sun and the gravity of the earth
combine to make a relatively stable
point that follows the earth around the
sun every 365 days so if we go out there
and we put up a sun shield a big
umbrella from that location we can block
out the sun the earth and the moon at
the same time
this is obviously no ordinary umbrella
the five individual layers are made of a
almost plastic-like material called cap
ton
200 000 watts of solar radiation strikes
the hot side and the sun shield will
only allow about 0.02 watts to get
through
if it were suntan lotion it would have a
solar protection factor
of about 10 million
so the telescope and the instruments are
exposed to cold space
the webb telescope is the most difficult
scientific project we've ever undertaken
it's got to unfold itself in space
james webb is obviously not going to fit
on the top of a rocket so something
that's that big has to be folded
a consequence of this
folding up is that we have to be able to
do the deployment in orbit
once we're above the atmosphere the
fairing drops away and james webb is
then sitting alone on top of the rocket
shooting towards the moon and out to its
final orbit
the solar panels have to come out very
quickly to power it
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over the next 29 days as a whole
sequence of activities that happen
the
very large sun shield has to be pulled
out and be separated and that is an
amazingly intricate series of steps
unlike hubble we are not orbiting the
earth we're going straight out a million
miles where no man has gone before so
servicing is not an option for us
all the release mechanisms have to work
if they don't deploy we're we've had a
bad day
we allow the telescope to cool down and
the instruments to cool down and then we
start focusing them that takes all
together six months to get all of that
set up and then we're pretty ready to
say let's try some science projects
web telescope has four instruments all
together
one is a near-infrared camera it's the
most sensitive of the instruments
number two is a near-infrared
spectrograph
that one spreads out the light of the
stars or galaxies into the spectrum
special invention we made for that one
was the micro shutter array where you
measure 100 separate galaxies at once
the third instrument is the mid infrared
instrument or miri
that's a special one because it picks up
wavelengths where the molecular
emissions are the strongest for the
coldest objects out there we'll be able
to look way back to where we think the
first objects may have been formed in
time
the fourth instrument is the slitless
spectrograph
it is used for extremely high angular
resolution images that might have
planets in them
on average every star in the galaxy has
at least one planet so when you look up
at the sky the pinpoints of light you
see are planetary systems not just stars
we are super excited about the launch of
the james webb space telescope because
it's going to bring us new data about
planet atmospheres and my mom and i are
going to be working together on sort of
disentangling that data
my mom is discovering new planets
and i take those planets and i try and
understand what their atmospheres are
like
most planets that have been discovered
were
noted because we observed something
about the star that indicated the
presence of a planet in orbit around it
you're measuring the brightness of a
star waiting for the momentary dimming
of light that happens if a planet in its
orbit around the star happens to pass
directly between the star and the
telescope
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we discover evidence of a planet buried
in data
that can feel like an abstraction we
have to pause and remember that these
places really exist
someplace
there's a lava ocean rising and falling
with the tide
some place there's an eastern horizon
where two stars are rising not one
we've only really been able to scratch
the surface in terms of what we know
about those planets but now with the
james webb space telescope we'll be able
to dig deeper and understand more about
what their atmospheres are like
by looking at the atmosphere itself
you can actually get an idea of what the
climate is like and you get an idea of
what the full chemical makeup of the
planet is
we want to study those atmospheres
because we think that there could be
potential signs of life encoded in those
atmospheres here on earth we have a very
specific chemical makeup in our
atmosphere that allows life to flourish
geology produces methane but life
produces methane in a hundred times
higher quantities
and so if we can look at this delicate
balance between co2 and methane on other
planets that could give us some
indication of life
one of the most exciting planets that
jwst is going to look at is the
trappist-1 system this is a star that's
just about the size of jupiter so it's
very small and it has seven earth-sized
planets orbiting around this star
three of those planets could be
potentially habitable
looking at those planet atmospheres is
going to be like this perfect laboratory
of science where we can sample the
atmospheres of seven different
planets potentially habitable
earth-sized planets are relatively
common we expect there to be maybe a
dozen billion such worlds in our galaxy
alone
earth didn't make its appearance until
billions of years after the milky way
formed but there are planets that formed
in those very earliest moments of the
milky way and imagine
how life could evolve on a planet given
10 12 billions of years of evolution
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web because it's so powerful you can't
predict what it's going to say
we have lots of reasons to be skeptical
of our understanding of the very early
universe we have a pretty good story
called the standard model of the
universe which is cosmic dark matter
cosmic dark energy ordinary matter and
gravity pulling things together after
the big bang
but people don't have any explanation
for where did the dark matter or the
dark energy come from
and we don't know that that's the only
kind of stuff out there so i think we
could get a big surprise way out there
in the early universe
i'm hoping you know in my heart that
james webb finds a whole new field to
investigate
even though i'm 62 years old maybe i can
go back to grad school get my phd on
something in a brand new field that was
started by james webb
every time astronomers build a powerful
new tool we discover something new
nature has more imagination than we
humans have
what makes us human is to be curious and
to
push boundaries and explore and increase
our understanding
of the universe jwst is the next piece
of that puzzle
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we are learning about our galaxy at a
very rapid pace
we've gone in just a couple decades from
finding the very first planet orbiting
another star to having a comprehensive
specific plan for identifying living
worlds
i
really hope that webb helps me to
understand what fraction of the planets
orbiting the goldilocks zone are true
earth analogs
i feel confident
that my grandchildren will be able to
look up in the sky and point to a star
and say there's life
i think that's going to be a
moment more profound than our copernican
moment that took earth out of the center
of the universe
it's going to put an end to cosmic
loneliness it's going to fundamentally
change
what we see when we look up in the night
sky
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you