Translator: Tijana Mihajlović
Reviewer: Nada Qanbar Good afternoon. It's an honor to be with you today
here at Utah State University. This institution has been
an important part of my life since I was a young boy, and I'm honored to be with you today. I'd like to invite you to go with me
on a journey of discovery, to see the Universe with new eyes. What do I mean by new eyes? Our eyes are sensitive to only a very narrow portion
of the electromagnetic spectrum. The wavelengths that are shorter
than what we can see are the ultraviolet,
the x-rays, and gamma-rays. Wavelengths longer than what we can see, we call them the infrared,
microwaves, and radio waves. But they're all part
of the same type of energy; we just can't see them with our eyes. But what if we could? That's what I'll show you today. The images you'll see today
were made with the telescope. This is a model of the telescope
that took these images. And it took in information
from the 2.6 to 26 microns out in the infrared. And using that sensor, we can see
objects as cold as 70 degrees Kelvin, or 70 degrees above absolute zero. Of course, we have to recolor
that data back into the visible, so we can see it with our eyes. Let me show you how this works. Here I have three identical mugs. One's filled with water
at a boiling point, one's filled with water
about body temperature, and one's filled with ice water. As you see them here, you're seeing the light
as reflected from the surface, and you can't tell anything
about the temperature from where you're sitting. That's because the color you see
is determined by the surface chemistry, not the temperature of the object. But what if we could see temperature? Let's bring up the image
from this infrared camera. Now it becomes very clear. This object on the right
is the hot object, the one in the center is nearly
the temperature of my hand, and this one is very cold. So, if we can learn
through technology to see in heat, we can learn a great deal
about the Universe. That's what you're going to see today. But before, one more thing
about Infrared Astronomy: we have to do it
from outside the atmosphere. Whereas the atmosphere
is quite transparent to the visible light that we see, it's opaque to the infrared. Let me show you an example. This plastic shroud is clearly
transparent to visible light. When I place it over these cups, you can see that it blocks
the infrared energy from getting out of the clear plastic. That same thing happens
with our atmosphere: we simply can't see the infrared
from here on Earth; we have to send
the telescopes out into space. So, let's go back to our next image. The WISE program stands
for Widefield Infrared Survey Explorer, meaning it's going to map the entire sky
in the infrared wavelengths. It's a program funded by NASA. It was led by the Jet Propulsion
Laboratory in California. The spacecraft seen here
was built and designed here at Space Dynamics Laboratory,
Utah State University. The spacecraft was designed and developed
by Ball Aerospace in Colorado. Scientists have known for a long time that infrared information about Universe
can teach us good deal about temperature and about the processes going on. So let me show you some of the images that were obtained
before the WISE mission. This is an image taken in 1990. Not really designed for high resolution, but it gave important
astronomical information. An earlier image in 1983 from IRAS
is a little bit better definition; you can see a bright star in the center,
some off-to-the-edges, and a little bit of the cloudy structure
around the stars. This is the first image that came
down from the WISE telescope. Scientists have spent
a decade of their life planning and waiting for this mission. They were anxious to see
what the WISE telescope would provide in terms of new data. Well, they were not disappointed.
Here's what they saw. A million pixels that provided information about the location of the stars,
the temperatures, and other information
important to the astronomers. Let's look at another example.
Here is more IRAS imagery. This shows some bright stars, kind of this cloudy structure
in the center, but not really exciting information. With the new eyes of WISE, we get this. Much more information and details about the structure
of the clouds, the stars, and the processes that are going on. It's an amazing, beautiful image
of the Universe. There is a piece of history
illuminated by the WISE mission. In 1572, there was a supernova
that humans observed because it was bright enough
to see it in the daytime, and it lasted for about 2 years. It was recorded and chronicled by a Scandinavian astronomer
named Tycho Brahe. If you look at that patch of the sky today
where the supernova took place, that's a pretty ordinary image. But as WISE scanned the Universe, the scientists asked,
"Could we see any remnant, any evidence
of the Tycho Brahe supernova?" Well, in fact, we can. This red object in the lower right
is the thermal footprint we can still see today
of Tycho’s supernova. So, Tycho was telling us the truth. This is another nebulae
or a cloud-like structure that shows pretty much
what we would see with our eye. As we get out into colder bands,
it's a little bit different structure, but as we get into longer wavelengths
and colder temperatures, the structure changes quite a bit, and we can see this more
cloud-like structure and fewer stars. As we go onto the red bands,
we see again more cloud-like structure, and the stars kind of fade away. When we combine those into a mosaic, we get this rich kind of carpet
of color that we see, the thing that's going on
in this particular nebulae. This is the Heart and Soul Nebulae, actually an image taken from Earth
in the visible wavelengths, and we can see
some of the cloud-like structure because the particles scatter
the light from the stars nearby; you're not really seeing
the temperature of the object itself. If we can see with temperature, we can see that with the WISE telescope
we get very different picture. We can see much more detail
about the structure, and that tells us something
about the processes going on. This is a very different
kind of structure. This is the thermal bow wave
in front of this star that's streaking through the Universe
at 5 million miles per hour. It's radiating so much energy that actually heats the particles
in space in front of it, and creates this massive
thermal wave in space. This is a dying star. We can see this energy being radiated
away from the star as it goes to the final years of its life. This is what you can see in the visible. But if we see it in the infrared,
we see quite a different structure; we see the kind of double halo
around the star. And our Sun is in this class of stars, and this is kind of the way
that our Sun will end its life a few billion years from now. The Hidden Galaxy is an interesting image because it can't be seen
in the visible range. As the light travels through space, passing through trillions
of miles of dust, this light is simply scattered away and never reaches
our sensors here on Earth. But the infrared wavelengths are longer, and they can traverse
to pass the dust better, without being scattered. Let me show you an example of what I mean. Let's come back to our
infrared images of the cups, and we can bring that up. You can see clearly
the energy from the cups, and here I have a black plastic bag. As you can see,
it doesn't transmit the visible light. But if I place this bag over the cups, you can see that the infrared energy
passes right through the plastic. That's kind of what's happening to the energy traveling
across the Universe that scatters the light away. So let's come back to our image. We can see the next image of Andromeda. Andromeda's our nearest neighbor. It has about three times
the stars of the Milky Way, about a trillion stars, and that's a massive object. If we could see it all, it would be
about six full moons wide, just off the plane of the Milky Way. We can't see it from Earth
because of the scattering; it's just too dim. But from space, we get
this marvelous image of Andromeda. This is the band closer
to what we would see with our eyes. In the cooler bands,
the longer wavelengths, we can see these cloud-like structures, and here we see the composite image
of the Andromeda, our nearest neighbor. If we peer out in the far-edge
of the Universe, we might think it's simply a black void. But WISE told us something different. In this particular patch of sky
through the WISE image we see this: clusters of galaxies,
each with hundreds of billions of stars, all over the night sky. We simply can't see them, but it just stretches our mind
to think how far away they are, and how many billions of stars
and billions of galaxies exist out in the edges of the Universe. Another image,
an ultra-luminous infrared galaxy. These are very bright objects. They're about a hundred times more radiant
than the entire Andromeda Galaxy, which is three times
that of the Milky Way. And again, these are viewed
in the infrared. Some of these objects, again,
are obscured by the dust, so we have to view them
with the infrared energies. And they are called DOGs, which stands
for the Dust Obscured Galaxies. Scientists having some sense of humor,
realizing how hot they are, had no choice but to call them hotDOGs. (Laughter) So, we know there are hot dogs in space. (Laughter) WISE has discovered
some very cool objects. We call them WISE discovers Y's, and this is Y class of brown dwarfs
you can see here. There are different kinds of dwarf stars. These are basically failed stars. They collapsed into their own
gravitational energy. They never reached
the temperatures in the center that are necessary
to reach thermonuclear fusion, and create a bright star
like we have in our Sun. WISE has found this very cool star in the sense the surface temperatures
are only about 80 degrees Fahrenheit; just a day on the beach. To give you an idea
how sensitive this telescope is, if you take a piece of that star
or a bit of matter by the size of a postage stamp
at room temperature, put it out in space,
and put this telescope 5,000 miles away, you can see the heat
from that postage stamp. So, exquisitely sensitive instrument. And it's found this new class
of brown dwarfs. The WISE sensor also found
a host of asteroids and comets. The most interesting one
is called the Trojan asteroid. It's called the Trojan asteroid because it's actually hidden
in the orbit of the parent planet. We'd seen these in other planets
of our Solar System, but one had never been found with Earth
until the WISE data revealed that. So we actually have a companion. It's exactly two months in front of us
in our orbit around the Sun. But it's not going in the nice
smooth ellipsis as the Earth does; it goes in a corkscrew or helical pattern
around its own orbit as it makes its way around the Sun. So, we have a friend out there clearing the path
in front of us every year. Let's take a look at this instrument. Again, I have a mock-up
of this instrument here at the side. The energy enters
the front of the telescope, where it's captured by the main mirror, then reflected back to a secondary
telescope mirror at the front, and it comes back
through a hole in the primary, where it's sent
to one of these four detectors. You're going to see
some of these information here. This is an example
of the focal plane array. This is the sensor or the camera
that actually captures the energy and converts it to electrical signals, and that creates the images that you see. The WISE telescope
has four of these sensors, and they cost two million dollars each. So, we'll be careful with that. (Laughter) The telescope sits on its standing
and goes down into this large cryostat, whose purpose is to keep the sensor cold. You may think,
"But space is already pretty cold. Why do you have to cool it?" Well, the energy from the Sun
and the energy from the electronics actually heat it to the point that you
cannot use the longer wavelengths. So we use solid hydrogen. It's launched into space with the sensor and it keep is down
to from 5 to 7 degrees Kelvin. So, it's very cold. We have to do that
so it doesn't see its own heat. We were able to put that sensor together
and then calibrate it. The calibration is important because we need to have scientifically
credible data for comparison years and decades from now. Here you can see the WISE telescope
being calibrated in our laboratory, where each one of those million pixels
on all four focal planes is calibrated individually
for linearity and responsiveness. With that data, we can take
the raw data from the telescope and convert it into absolute
physical measurements that will have meaning for years to come. Here we see the sensor
atop the spacecraft, which provides the telemetry,
the steering, the radio transmission etc. On the right you can see
the sensor sitting atop the rocket, just prior to its launch. The WISE was launched
in the middle of December of 2009 from the Vandenberg
Air Force Base in California. Just a beautiful morning
and a perfect launch. It has been just an amazing
and successful mission. These images of the Universe
and these rich vibrant colors have changed my view of the Universe. It's not just a dark stage where the characters
are just points of light that carry out this dark cosmic drama. If we could see all the energy
that's out there as we see here, it's a lot more like an action. There are exploding stars,
there are dying stars, there are new ones being born. We have character actors. We've got brown dwarfs. We have Trojan asteroids,
and, well, we even have hotDOGs. (Laughter) You may be asking yourself,
"If this is really an action movie, is there a superhero around
to take the starring role?" Well, WISE has found
evidence of one, with this: the Helmet of Thor. (Laughter) If Thor is out there, he is a big guy, because that helmet
is 30 light-years across. And that star in the middle
is 200,000 times brighter than our Sun. Let's end our journey today by coming back
to our galactic home, the Milky Way. This amazing image
is a composite of the Milky Way as viewed from Earth. You can see the interesting structure
where stars are being born and stars die, and the very bright center
of the Milky Way, where it's believed
to be a massive black hole. Over time, we've learned how to - science and technology coupled
with human determination and curiosity. We've learned how to cross the continent,
sail over the oceans, fly through the air and journey out into space. But I think each of those
journeys of discovery outward is part of the journey
of discovery inward. That was expressed well
by T.S. Eliot when he wrote, "We shall not cease from exploration, and the end of our exploring
will be to arrive where we started and to know the place for the first time." I hope that you've enjoyed
this journey of discovery with me today. I hope, too, that this journey outward
may be part of a journey inward, that we might see ourselves,
our neighbors, our nations, our amazing planet with new eyes, and come to know them in new ways. If we can make those discoveries, I think those will be
the most important ones of all. Thank you. (Applause)
