Carl Sagan once said you have to know the past to understand the present it wouldn't
be wrong to add that a knowledge of the past also helps us to shape our future
humanity has been looking up to the stars since the dawn of time to understand where we come
from and what tomorrow holds in store for us we were limited by our capabilities dreaming of time
machines that could show us the past present and future at the same time but now we have it this
December 22nd may become known as the day the universe changed that Wednesday NASA expects to
launch the James Webb space telescope we might even glimpse the very origins of our universe
and and it's going to answer two big questions for astrophysics where do we come from and are
we alone and we're looking forward to getting those results well not exactly a time machine
but a machine that can peer into time and tell us what to expect in the future the gold-plated James
Webb telescope is the largest space observatory in human history and it's ready to unravel the
secrets of the universe that have stupefied our minds for centuries welcome the fact nominal in
today's video we look briefly at the development of the James Webb space telescope and then take a
deep dive into incredible marvels and mysteries astronomers expect to encounter and unravel
when Hubble was still in diapers relatively speaking the concept that became Webb was
proposed as the next generation space telescope and six years later adopted the name of nasa
pioneer James e Webb with collaboration from the European and Canadian space agencies
nasa targeted 2007 for the JWST launch that of course was off by about 14 years due largely to
the chasm of differences between this new marvel and Hubble so how are the two different Hubble has
tremendous range in the spectrum of visible light and a more limited region to the ultraviolet
and infrared wavelengths in fact the cosmic law attributed to Edwin Hubble and others
was discovered by observing that the red shift of galaxies is directly proportional to their
distance from earth something that the Hubble telescope studied up to its capability this is
where the JWST's unique abilities jump in and why nasa prefers to call it the successor rather than
the replacement to Hubble it is specifically focused on the infrared part of the spectrum
which means it can see light emitted by stars and galaxies that existed over 13 billion years ago
which makes this telescope in essence a time machine just to see through clouds of galactic
dust in our galaxy that absorb visible light is a tremendous advantage of infrared images and
while Hubble does have that capability the JWST will peer out to far greater distances further
back in time also the light gathering ability of the JWST dwarfs that of Hubble the web mirror is
much larger and 100 times more powerful to see the size difference compare the diameter of a softball
to that of an NBA basketball Webb also has a field of view roughly 15 times that of Hubble
while Hubble for three decades has orbited the earth from 570 kilometers the JWST will orbit
the sun at 1.5 million kilometers from earth at what is called the second lagrange point or l2
heat radiation evenslight interferes with detection of infrared sources much further away
so for optimal performance the jwst needs to be minus 233 degrees celsius or minus 388 degrees
fahrenheit thus the much further distance and five-layer tennis court size sun shield to
keep background heat from the sun from interfering with Webb's infrared sensors picture a large beach
umbrella and its advantages on a hot day so what are we looking for and what do we expect to find
after all this is why three decades and 10 billion dollars are invested in the JWST let's take a look
remember that time machine moniker often used to refer to JWST
there's a great reason for that light from the very early universe is quite red-shifted
and some is out of reach of anything we've had up until now web is specifically designed for near
and mid infrared observations that will reach farther back through time and open windows into
the beginnings of the universe while we cannot see the big bang because stars and galaxies had
yet to form scientists hoped to peer into the period just after the cosmic dark ages
to when the first stars and galaxies came to be called the re-ionization era
this was perhaps as soon as one hundred thousand years after the big bang and scientists are
counting on Webb to hopefully pin down more precisely when the universe's first light appeared
day one James Webb space telescope itinerary survey half a million galaxies in one narrow
patch of sky about the size of three full moons in a project called Cosmos Webb okay it's actually
not day one since the JWST will be in space for weeks before it's down to operating temperature
and about six months before routine scientific operations begin but for the schedule 208.6
observing hours a team of nearly 50 researchers will survey some 500,000 galaxies including
an unprecedented 32,000 in mid infrared to dig into the formation and evolution of our universe
oh did we mention that Webb will quickly release jaw-dropping eye candy images to the public
we now have photographs of black holes okay not of them since light cannot escape their grasp
but we have the closest thing possible from earth with the startling 2019 image of the colossus at
the heart of the galaxy m87 captured by the event horizon telescope EHT project
astronomers believe these supermassive black holes are at the center of virtually every
large galaxy those actively feeding on enough surrounding matter create a light so bright
that it outshines the rest of the galaxy and are called quasars even more recently in early 2021
the polarized light image of the center of m87 also came from the EHT project which uses eight
radio telescopes around the world in collaboration to form a virtual earth-sized megascope
now picture this planetary megascope teamed up with web's capabilities in space exactly the JWST
will work with the EHT project to capture the first image of our own milky way's supermassive
black hole known as sagittarius a star or SGR a star our cosmic neighbor relatively speaking has
a mass of 4.3 million suns and is an uncomfortably close 27 000 light years from earth the JWST is
expected to give astronomers an incredible view of the flickering flares regularly emitted from
our galactic core something not detected from m87 thus far that's not even the wildest black hole
exploration Webb has on its to-do list astronomers have found three enormous quasars more than 13
billion light years from earth as nasa estimates the universe to be 13.8 billion years old the
JWST will explore these objects with billions of solar masses that date back to the early universe
our new time machine is about to give us a look at primordial galaxies and possibly habitable planets
the number of confirmed exoplanets has eclipsed 4 000 since they were first
discovered about two decades ago and the total is doubling roughly every 27 months
the JWST is about to tell us far more than we know about these other worlds as it studies
their atmosphere and even looks for the building blocks of life one way is with the transit method
which looks for the dimming of a star's light as the planet passes between the star and web
in conjunction with ground-based observatories Webb will help measure the planet's mass
and provide a spectroscopy of its atmosphere spectroscopy uses the intensity of light
at different wavelengths measured when the planet passes in front of the star
when a planet passes in front of a star the starlight passes through the planet's atmosphere
if say the planet has sodium in its atmosphere the spectra of the star added to that of the planet
we'll have what we call an absorption line in the place in the spectra where we would expect to
see sodium this is because different elements and molecules absorb light at characteristic energies
this is precisely how we know where in a spectrum we might expect to see the signature of sodium
methane carbon dioxide or even water Dr. Marcia Rieke professor at the University of Arizona
and principal investigator of JWST's NIRCam believes that it's possible that we may not
only find more planets but potentially more planets with atmospheres like ours
it's not just objects 13 billion light years away that the James Webb space telescope will explore
our own backyard is about to be revealed to us in ways we had only ever imagined everything from the
outer planets to Kuiper belt objects and asteroids the JWST will allow us to see our cosmic neighbors
in a new light scientists will be able to study the composition of surface ices and volatiles
on a number of bodies in our system as well as the new class of icy comets in the asteroid belt
planets and their satellites will also come under web scrutiny most of which will be used
in collaboration with other nasa solar system missions and ground orbiting and deep space
observatories Webb will be paying close attention to mars by surveying and following up on previous
findings of mars rovers and landers we may finally find out whether our neighboring red planet had
a habitable past further out expect Jupiter to get special attention from the JWST as it images
the planet's many spectacular features its moon Ganymede will also be studied for the potential
hidden ocean between its icy crust and we can expect an investigation into the fiery moon Io
and its volcanic wonderland the JWST will also enhance our knowledge of the mineralogy of our
neighboring planets its unprecedented sensitivity and spectral resolution will be used to understand
more of molecular and mineral spectral wavelengths inaccessible from the ground not to mention
monitoring planetary and satellite weather and seasonal changes and inevitably so much more
since its conception decades ago the mission of the James Webb space telescope has morphed
simply because of expanding knowledge of the universe mysteries that were not even considered
when the design began are front and center today and what about tomorrow astronomers fully expect
the unexpected and with our incredible universe they will not be disappointed nasa calls these
targets of opportunity and says that Webb's attention may be diverted to the unexpected in as
little as two days the observatory will be able to slew up to 90 degrees in less than an hour so what
are your expectations for the James Webb space telescope what would you like most to be revealed
about our universe tell us in the comments and as always thank you for watching Factnomenal