humanity has always been drawn to the
night sky we draw pictures in the Stars
track the planets see signs importance
and celestial objects but so much of the
universe is beyond our reach
vast distances separate us from the
sites that might answer some of our
biggest questions how do galaxies form
how do stars and planets come to be do
distant planets have the conditions
necessary for life to construct and test
our theories we need to see what's
happening so we build tools to extend
our vision they get bigger more powerful
more advanced as time goes on astronomy
stops relying on the light we can see
only with our eyes
when you look at the world here seeing
something we call visible light but
visible light is really only a certain
form of radiation our universe is full
of many different types of radiation it
surrounds us our bodies evolved to
detect visible light with our eyes but
they also evolved to detect another kind
of radiation called infrared light our
bodies feel infrared light is heat this
infrared radiation was discovered by the
astronomer Frederick William Herschel
Herschel knew that a prism could be used
to break white light into colors he
wanted to know whether the colors had
different temperatures they did but then
Herschel measured the empty space just
beyond the red light though no sunlight
was visible it was hot Herschel had just
discovered invisible infrared radiation
humanity now knew that there were forms
of radiation that could not be seen they
could be anywhere all around us how many
were there what were they up to
what were they hiding obviously we had
to find out a type of energy that
travels through the universe in the form
of waves is called electromagnetic
radiation the entire range of it from
high-energy gamma rays to low energy
radio waves is called the
electromagnetic spectrum
you
although our eyes can see only visible
light we can build tools like infrared
detecting cameras to see other forms of
radiation these tools are man-made eyes
that view invisible radiation for us and
transform it into pictures
objects can emit all kinds of radiation
huh observing the entirety of that
radiation gives us a true picture of an
object when we turn these tools on space
they open up the entire cosmos to us in
its full glory when we look at the night
sky we see stars and planets galaxies
and nebulae in the form of visible light
but if we could see in infrared light
the sky would appear very different for
one thing infrared lights long
wavelengths penetrate clouds of gas and
dust
the shorter wavelengths of visible light
are stopped and scattered as they fight
through collections of particles so by
detecting infrared light we can see
through clouds of gas and dust to warm
objects inside like just forming stars
the objects that don't glow with any
visible light of their own like planets
are still often warm enough to radiate
infrared light perhaps allowing us to
glimpse them and by observing how
infrared light from a planet star passes
through its atmosphere we acquire clues
about the planets composition the dust
left behind by distant planets as they
form will also glow in infrared helping
to show us how planets are born so
infrared helps us see objects like these
in our own galactic backyard but it can
also help us observe the first objects
that formed in the universe after the
Big Bang
imagine you gave a letter to the post
office and they galaxies billions of
light years away and addressed it to
earth it would travel for an incredibly
long time when it finally arrived at its
destination the person who opened it
would be getting news from billions of
years earlier the light from the first
stars to shine in the universe is
something like that
it left the stars ages ago and is still
out there in space traveling the vast
distances between galaxies if we could
see it we could see those galaxies as
they were in the early universe
essentially we would be seeing back in
time but we haven't been able to see it
why because the universe is expanding as
light travels across space it's
stretched like taffy by the expansion
the first stars gave off mostly visible
and ultraviolet light but the stretching
changes those waves into infrared light
this is called red shifting the only way
to see that light as it arrives in our
region of the universe is to look for
that
faint infrared glow by capturing it we
will be able to create images of the
first galaxies to form in the universe
by witnessing the birth of the first
stars and galaxies we deepen our
knowledge of how the universe as we know
it came to be how did we get from those
first blazing stars to the islands of
billions of stars we see today what will
we learn about how galaxies grow and
evolve
how did the chaos of the early universe
transform into order and structure NASA
is currently building the James Webb
Space Telescope with its huge infrared
capturing mirror and distant orbit far
beyond the moon Webb will allow us to
view the cosmos as we've never seen it
before Webb will search for signs of
water vapor on planets around other
stars it will take pictures of the
universes infancy Webb will reveal the
hidden stars and solar systems forming
within cocoons of dust the answers to
some of the universe's biggest mysteries
and more questions we haven't thought to
ask are waiting out there for us in the
form of infrared radiation all we have
to do is look
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