In a specialized building like this, NASA built a new
machine for science. The James Webb Space Telescope
is a complex collection of scientific instruments designed to tackle
some of the biggest questions in astrophysics
Webb has 4 instruments contained within the Integrated Science Instrument Module
or ISIM, located directly behind the primary mirror.
They’re all designed to observe in infrared light which is
invisible to human eyes. Infrared is a longer
wavelength of light located on the electromagnetic spectrum
just beyond light human eyes can see. We feel infrared light
as heat.
Each of the instruments play a different scientific role.
The Near Infrared Camera, or NIRCam, is the main
imaging system. NIRCam will look back in time to
study the formation of the earliest stars and galaxies.
One aspect of its design includes the ability to block light
from a bright object so much that a much dimmer object nearby
might be observed. This means, that in addition to looking at
distant objects from the earliest days of the universe, scientists
hope to study aspects of planets orbiting nearby stars.
The NIRCam instrument also plays a key role in the process
of aligning Webb’s 18 primary mirrors, its secondary mirror
and its Fine Steering Mirror, using a clever technique
called Wave Front Sensing and Control.
One of the best ways to find out new information about
distant objects, is through the analysis of the light those
emit. The Near Infrared Spectrograph, or NIRSpec
will collect spectral information about distant objects in order
to determine their composition, temporature, velocities and mass
to do this, NIRSpec will employ a unique technology
called a Microshutter Array. It’s an extraordinary
collection of mechanical shutters, each barely wider than the thickness
of a human hair, that can simultaneously collect
high-resolution data from up to 100 distant objects
different wavelengths of light present different information
and each of Webb’s scientific instruments pursues different slices
within the infrared spectrum. The Mid-Infrared Instrument, or MIRI
will look at wavelengths of light that are a little longer than
the other instruments will observe. Not only will this enable
extraordinary images, but it will also allow scientists to search
for planets around distant stars, dust warmed by starlight
and protoplanetary disks and comets and asteroids in our
own solar neighborhood. MIRI is
the coldest instrument on Webb, operating at just 6 degrees
Celsius or 11 degrees Fahrenheit above absolute zero.
The fourth part of Webb’s instrument suite is two instruments.
The Near Infrared Imager and Slitless Spectrograph (NIRISS)
working in concert with the Fine Guidance Sensor will look
ancient light in the universe and information about planets around distant
stars. The Fine Guidance Sensor helps keep Webb
pointed and perfectly steady during all observations.
Together, these instruments and
the technologies that will enable them will make up one of the most complex and ambitious
undertakings in the history of humanity
This is the James Webb Space Telescope.
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