Original subtitles

The night sky is a time machine. The further we look out

into the universe, the further back in time we reach. What

we see in the night sky is only a small percentage of the

contents of the universe. Most is dark matter and dark

energy. We know it exists, but its nature eludes us for the moment.

No longer hampered by a hazy, often polluted atmosphere,

telescopes and other sensors have been able to obtain

clearer images from orbit, thanks to advances in technology

and engineering. In the 1960s, satellites began to explore

the cosmos surrounding us. They saw beyond visible light

into ultraviolet, infrared, X-ray and even gamma rays. Like

the universe itself, our understanding of its beginnings,

construction, evolution and future is evolving and

constantly expanding. In the last two decades of the 20th

century, the United States and other nations began to

develop more substantial research programs, utilizing larger

and more complex space-based telescopes. For hundreds of

years, thousands of years, humans have thought the universe

is a very static place. If you go out at night and look into

the night sky, you will see that things don't really change

much. The universe appeared very static for a long time. We

now know this is not true. The universe is a highly dynamic

place and things are happening all the time. Every single

second, a star explodes in a gigantic supernova explosion

somewhere in the universe. And we have to go and find it. We

have to build instruments that are capable of finding those

unforeseen events. The Cosmic Background Explorer, or COBE

satellite, started crystallizing the big picture of the

universe by mapping the microwave background radiation left

over from the early universe. Its successor, WMAP, created

the most detailed portrait of the infant universe. Well,

because it takes the light over 13 billion years to reach

us, we are seeing now what the universe looked like then,

over 13 billion years ago. So it's a fossil remnant of what

the early universe was like. And just like fossils were used

to study the past, we used this light to study what the

universe was like way back near the very beginning. And you

can see in there blue spots and red spots. And what those

correspond to are slightly hotter and colder images of the

sky. That's a picture there, those hot and cold spots, that

pattern. It's really the afterglow of the Big Bang. On a

deeper, long-term level, it's this amazing consistency

that the picture we can put together of the universe is

relatively simple, that the pieces fit together. It's a

stunning confirmation of the study of cosmology for many

years now that it's just built up and here it is. In some

ways, we're getting to know the cosmos like we know our own

backyards. ESA's Planck spacecraft joined the fleet and

expanded on their observations. Together, they were able to

map vast regions in multiple wavelengths, enabling

astronomers to determine the size, shape and age of the

known universe. So 370,000 years after the universe began in

a Big Bang, all that existed was a hot plasma similar to a

candle flame. Protons and electrons, seen as the red and

green balls, were bouncing around, scattering the light. The

particles of light, called photons, shown in blue, couldn't

go far without colliding with an electron. As the universe

cooled, the protons and electrons could pair up, forming

hydrogen atoms, and the light was free to travel. It's been

traveling freely ever since, through the dark ages before

there were stars, then past the formation of the first

stars. As the universe expanded, photons lost energy,

changing color. They went past clusters of galaxies. The

path of the photon is slightly bent by the gravity of

the clusters. Now and then, going through a cluster, an

electron, that green ball, would collide with some of the

photons. They would change their path, pass more matter,

more little wiggles due to gravity and mass. The photons

traveled for 13.8 billion years before they reached the

Planck detectors and died a glorious death, giving up the

information that they had gleaned, passing through the

entire universe to our instruments, and enabling

us to make this beautiful map of the universe.

The various satellite telescopes have sensors designed for

use in multiple wavelengths of the electromagnetic spectrum,

from near-to-far infrared light, through visible and

ultraviolet frequencies, to X-ray, gamma, and cosmic ray

detectors. Each can reveal unique aspects of the

construction of stars, nebulae, galaxies, and the exotic

blazars and black holes.

However, in the public's eye, the poster pin-up star of

the latest generation would undoubtedly be the Hubble Space

Telescope.

Over its 25-year lifespan, Hubble has produced some of the

most amazing imagery of the cosmos, as it delves back in

time through visible and infrared light.

Another advantage of Hubble is its long lifespan, thanks

to several maintenance missions, which allows it to study

objects over a long period of time with some amazing results.

Newborn stars eject streams of matter into the surrounding

star-forming region. Known as Herbig-Harrow objects, these

supersonic jets can be seen to change over a very short time

span. If you see just a single picture from Hubble, you can

interpret it in many different ways. But the fact that

Hubble has been around for as long as it has been means by

taking multiple images, you can actually stitch them

together and watch how the material moves. And so that

really gives you the only way to give true insight into the

physics of the dynamics of what's going on. The Horsehead

Nebula in the Orion constellation, silhouetted by glowing

gas, is a good example. Infrared can see right through,

revealing its dark secrets. The Spitzer

Telescope is one of NASA's great observatories.

Spitzer is an infrared telescope, which means it sees

through the dust that's out in space. And by seeing through

the dust, we get to pinpoint the stellar nurseries that are

out there where stars are being born. We've been flying for

about 10 years. That's about 3,600 days. We have 5,000

published papers. That means every day a new paper based on

Spitzer data, announcing new results and new discoveries,

is published, which to me is absolutely amazing. Spitzer has

made several surprising revelations within our solar system

and beyond. It helped pinpoint some of the most distant

galaxies in the universe. And Spitzer's ultra-high

resolution map of the Milky Way substantially improved our

understanding of our own galaxy structure.

Japan and ESA had launched their own infrared telescopes

in various infrared wavelengths. The European Herschel in

particular focused on massive star formation regions.

We are really happy to have new things and to understand,

trying to understand, because we are making a new step

towards our understanding of massive star formation. So the

idea is that Herschel can reveal this population of highly

embedded stars that are formed in gas and dust cocoon. But

that are not visible at optical wavelengths, for example. So

we need Herschel to detect all this population of very young

stars. The next great space-borne infrared telescope is the

James Webb Telescope, which is nearing test completion in

preparation for its launch in 2018. It will have a 6.5 meter

primary mirror, almost three times larger than Hubble.

However, ground-based telescopes are also working in the infrared spectrum.

So there is a large complementarity between space and

ground. From space, with the Hubble images, you can

characterize the images, you see the images much better.

With the ground-based telescopes, you can take that light

and look at spectra, and then find the redshifts, for

example, for distant galaxies. Or you can take infrared

observations, which Hubble couldn't do for a long time, to

then see how these objects look in the infrared. Together,

they have delved into the star-forming nebulae, left over

from exploding supernovae, and witnessed the birth of stars.

Another observational tool in the electromagnetic spectrum

for astronomers and cosmologists is the X-ray band. An

amazing discovery of the last 20 years is that every galaxy,

like our own Milky Way, has a massive black hole at its

heart. And as material from this galaxy, dust and gas, falls

onto this central black hole. It radiates, and we can see

that. So we look at the sky in visible light, we see stars.

If we look at the sky in X-rays, we see black holes. You can

observe X-rays from very distant objects. So you can

investigate the cosmic structure of the universe. So you

investigate the matter distribution in the universe while

observing the galaxies, the active black holes in the center

of the galaxies, to very far distances. And this is very

important for cosmology and to learn about the origin and

the evolution of our universe. X-rays are absorbed in our

atmosphere, so X-ray detectors must be placed at either high

altitudes by balloon or into orbit. NASA's flagship X-ray

telescope and one of their great observatories is Chandra.

If you want to find black holes, you want to use an X-ray

telescope. What we're tending to find is that the cluster of

galaxies has a bright central galaxy in the middle. It's

often an active galaxy or a quasar, so a supermassive black

hole in the middle of a big galaxy. Because when the cluster

is forming, a lot of material tends to fall to the middle,

so you get the biggest galaxy in the middle. So you see the

power of an observatory, an observatory like Chandra with a

state-of-the-art telescope and these imaging and

spectroscopic capabilities of its science instruments can do

things that maybe weren't even things that you planned on

doing because you didn't know about them at the time. And a

lot of the science with Chandra falls in that category. The

most recent telescope launched is Newstar, which has the

ability to focus X-rays for a much sharper image. One of

Newstar's main scientific goals is to make a full census of

black holes in the universe. X-rays have also revealed the

explosive processes of nova seen only at these wavelengths.

ESA have their XMM-Newton studying cosmic evolution

and Integro, the international gamma ray astrophysics

laboratory, looking at gamma ray frequencies, revealing

unseen structures and new sources of gamma rays. So Integro

is important because it's one of the few satellites which

look in gamma rays. And together with other satellites and

observatories around the Earth you can get a complete

picture of how these stars evolve. And without Integro

you're missing a large piece of the puzzle. We want to know

how did they produce the elements which we are made of.

These are the objects which throw all the different kinds of

material into the universe and they wander off into space.

And we are made of all these elements which are produced by

the supernova. So it is important for us to know where does

life originate and how does it originate. Gamma rays are at

the top of the electromagnetic spectrum, the most energetic

and powerful photons which stream from black holes,

exploding stars and even from our own star, the Sun.

Originally called GLAST, the Fermi Gamma Ray Space Telescope

observes the entire sky in high energy gamma rays every

three hours, creating the most detailed map of the universe

ever known at these energies. When it detects a new gamma

ray burst, it works in conjunction with the SWIFT satellite.

Then SWIFT is able to spin rapidly across the sky and point

an X-ray telescope and an optical ultraviolet telescope

at the possible location of the gamma ray burst. GLAST is

primarily devoted to seeing in a new energy range. It's

designed to pick up at the upper end of the SWIFT energy

range and carry it on up to much higher energies. And it

allows you to just see stranger and more exotic things the

further up in energy that you go.

GLAST and SWIFT are very different. SWIFT is like a nimble

small satellite that points here and there, but it isn't

surveying the whole sky, it's pointing in its particular

objects. GLAST looks in the high energy gamma ray sky, it

looks over the whole sky at all times. So when we see

something interesting with GLAST, we can ask SWIFT to go

look at it with their other telescopes and gain additional

information about it. We don't know what will happen over

the next 10 years, hoping that SWIFT will still give us

exciting data. But what we do know is that SWIFT will give

us exciting new data. Because of its pure nature, this is

what it was built for, to study new unforeseen unexpected

events. And they will inevitably happen. Cosmic rays consist

of protons, alpha particles, atomic nuclei of heavier

elements, electrons, their antimatter partner positrons,

and gamma rays. Studying these particles may answer some

fundamental questions, like the unexplained absence of

antimatter and the nature of dark matter in the universe.

Calibration of positron is important because when you have

dark matter collision with another dark matter, you produce

excess positrons. So the characteristics of the excess

positron tells you what's the origin of dark matter.

About 80% of the matter in the universe is invisible to

telescopes. This dark matter neither reflects, absorbs, nor

emits light. Yet it interacts with matter via a

gravitational influence which can be seen in the orbital

speeds of stars around galaxies and in the motions of

clusters of galaxies. Yet despite decades of effort, no one

knows what this dark matter really is. This visualization

shows galaxies composed of gas, stars, and dark matter

colliding and forming filaments in the large-scale universe,

providing a view of the cosmic web. It is believed that dark

matter provides the framework for this web. Galaxy clusters

are the largest gravitationally bound structures in the

universe. It is also believed that after the Big Bang, the

universe originally decelerated in its expansion, but then

changed gears and began to accelerate.

Important discoveries in astronomy and astrophysics was the

discovery of dark energy, and that is that the universe is

accelerating apart. What people are trying to do using

various different techniques and again in all the different

wavelength bands is to measure the parameters to

characterize the dark energy. With a launch date set for

2020, ESA is building Euclid, a space telescope which, it

is hoped, will chart dark matter and dark energy's effect on

the universe. I'm working on Euclid. That is a mission to

map the universe, and for that we built a highly precise

telescope in which we can map dark matter structures,

as well as derive the properties of the dark energy.

Understanding dark energy will allow us to understand the

future of the universe. The interesting thing is we get more

and more dark energy. Why? Because our universe is

expanding, and with our expanding universe we get more dark

energy in our universe. Now the ordinary matter, so dark

matter and normal matter, is not expanding, it's diluting.

So the fraction of dark energy compared to normal matter is

increasing in time. When the universe expands more and more,

we get more volume of our universe, we get more space, and

we get more dark energy. The leading particle physics model

for dark matter is called weakly interacting massive

particles, or also known as WIMPs. These guys just fly

through the universe without even bumping into anything

or each other. The idea of two WIMPs coming together,

annihilating and forming gamma rays, is kind of like two

bullets hitting head on in a crossfire. It's very rare, but

when you go to the area around a supermassive black hole, we

expect the density to be much higher, so the probability of

annihilation is much higher in this detection with a gamma ray telescope.

In his theoretical process, Schnittman's computer simulation

shows particles of dark matter around a massive spinning

black hole. All of the action takes place close to the black

hole's event horizon, the boundary beyond which nothing can

escape, in a flattened region called the ergosphere. Within

the ergosphere, the black hole's rotation drags spacetime

along with it, and everything is forced to move in the same

direction at nearly the speed of light. Concentrated fast

-moving dark matter particles collide and make gamma rays,

but only some of this high-energy light can escape the black

hole, in this case from the left side, where the black hole

is spinning towards us, giving us a lopsided glow of high

-powered gamma rays. The simulation tells astronomers that

there is an astrophysically interesting signal they may be

able to detect as gamma ray telescopes improve. Schnittman

believes this would be conclusive evidence of the WIMP

model. To me, dark matter, black holes, two of the most

elusive things in the universe coming together to help

explain each other is quite poetic.

Future missions will see a gravitational wave observatory

to study gravity waves and test Einstein's theory of general

relativity.

The Athena mission, mapping hot gas structures and searching

for supermassive black holes due to launch in 2028.

The Sloan Digital Sky Survey, the most ambitious

astronomical survey ever undertaken, will provide a three

-dimensional map of about a million galaxies and quasars.

The recently refurbished and upscaled CERN, Large Hadron

Collider, is one of the tools in search of WIMPs and other

exotic particles that may help explain the fabric of the cosmos.

Then, perhaps, the scientists, astronomers and engineers can

turn their attention to other mysterious theories brought

about by particle physics, such as multiple dimensions,

entire universes beyond our own, and what lies beyond the

event horizon. These, in time, will become the new frontier.