♪Music♪
Narrator: The universe. For all we have
learned about it, we have still only scratched the surface.
Everything that we can see around us makes up less than
5 percent of what's actually out there.
All the rest is called dark matter and dark energy. What are they?
We still don't know, even thought they determine the fate
of the universe. We have confirmed over
3,000 planets orbiting stars other than the Sun, but most of these
extrasolar planets are huge, and very close to their host
star. How common are planetary arrangements like our own?
And how many planets in our galaxy have the potential to harbor life?
These fundamental questions are
part of what drives NASA science, and they spur the development
of new space observatories. WFIRST,
the Wide Field Infrared Survey Telescope, is one of these.
WFIRST is built on an existing telescope
that is very similar to Hubble, but with the added benefit of
25 years of technological development. Each of the
Wide Field Instrument's images will have the depth and clarity of Hubble,
but cover a sky area 100 times larger.
That's thanks to an arrangement of 18 sensors in the camera to
Hubble's one. Viewing the sky in infrared wavelengths
allows astronomers to see relatively cool objects,
like interstellar gas, dust and exoplanets,
as well as stars.
WFIRST will lead the push to understand
dark energy, a mysterious pressure that is making
the universe expand ever faster. Dark energy makes
up 68 percent of the cosmos, and its properties--
whatever they are--determine the fate of the universe.
But no one knows what it is, or exactly how it behaves.
Another mysterious component of the
universe WFIRST will study is dark matter. Dark matter
accounts for 27 percent of the cosmos--5 times
as much as the matter we can see--but has remained invisible to us.
We can detect it by seeing how its gravity warps
light from distant galaxies, a process called
gravitational lensing. WFIRST's powerful
2.4 meter telescope will also help us in the search for
extrasolar planets, or exoplanets. Using the
same gravitational lensing principles, WFIRST will
watch for so-called 'gravitational microlensing events',
a unique light signature caused when a planet and its host star
pass in front of a background star. This technique
extends planet-detection capabilities to smaller and more distant
worlds than other methods, so it can catch ones that have
eluded us before. WFIRST's enormous field
of view will allow scientists to watch huge portions
of the Milky Way for these microlensing events. As a result,
they will be able to complete the census of exoplanets
begun by Kepler. To deepen its study
of exoplanets, WFIRST will also be outfitted a
beyond state-of-the-art coronagraph. The coronagraph works
by masking star light to reveal the faint light reflected by any
potential planets. WFIRST's coronagraph
will directly image and analyze Neptune-size planets
in orbits slightly greater than Earth's. Existing coronagraphs
can only image larger planets that are much more distant
form their host stars, so this new capability
represents a dramatic improvement. In order to make
all these measurements, WFIRST will move to nearly
1 million miles from Earth and orbit a special area of space
called a Lagrange point. This particular point,
called Earth-Sun L2, is one of several locations
where the combined gravitational effects of the Sun and Earth, create a
zone of stability where a spacecraft can pace Earth as it orbits.
WFIRST will be a way to answer many
of the biggest questions about the universe. Questions like
"how does the universe work?" and "are we alone?"
Its wide-field view and coronagraph will compliment
missions like the James Webb Space Telescope and the
Transiting Exoplanet Survey Satellite, TESS.
WFIRST will be an indispensable part of space science
during the next decade and beyond.
[Beeping]