technologist and astronomer called William Herschel

noticed an object on the sky that

didn't quite move the way the rest of the stars did.

And Herschel's recognition that something was different,

that something wasn't quite right,

was the discovery of a planet,

the planet Uranus,

a name that has entertained

countless generations of children,

but a planet that overnight

doubled the size of our known solar system.

Just last month, NASA announced the discovery

of 517 new planets

in orbit around nearby stars,

almost doubling overnight the number of planets

we know about within our galaxy.

So astronomy is constantly being transformed by this

capacity to collect data,

and with data almost doubling every year,

within the next two decades, me may even

reach the point for the first time in history

where we've discovered the majority of the galaxies

within the universe.

But as we enter this era of big data,

what we're beginning to find is there's a difference

between more data being just better

and more data being different,

capable of changing the questions we want to ask,

and this difference is not about how much data we collect,

it's whether those data open new windows

into our universe,

whether they change the way we view the sky.

So what is the next window into our universe?

What is the next chapter for astronomy?

Well, I'm going to show you some of the tools and the technologies

that we're going to develop over the next decade,

and how these technologies,

together with the smart use of data,

may once again transform astronomy

by opening up a window into our universe,

the window of time.

Why time? Well, time is about origins,

and it's about evolution.

The origins of our solar system,

how our solar system came into being,

is it unusual or special in any way?

About the evolution of our universe.

Why our universe is continuing to expand,

and what is this mysterious dark energy

that drives that expansion?

But first, I want to show you how technology

is going to change the way we view the sky.

So imagine if you were sitting

in the mountains of northern Chile

looking out to the west

towards the Pacific Ocean

a few hours before sunrise.

This is the view of the night sky that you would see,

and it's a beautiful view,

with the Milky Way just peeking out over the horizon.

but it's also a static view,

and in many ways, this is the way we think of our universe:

eternal and unchanging.

But the universe is anything but static.

It constantly changes on timescales of seconds

to billions of years.

Galaxies merge, they collide

at hundreds of thousands of miles per hour.

Stars are born, they die,

they explode in these extravagant displays.

In fact, if we could go back

to our tranquil skies above Chile,

and we allow time to move forward

to see how the sky might change over the next year,

the pulsations that you see

are supernovae, the final remnants of a dying star

exploding, brightening and then fading from view,

each one of these supernovae

five billion times the brightness of our sun,

so we can see them to great distances

but only for a short amount of time.

Ten supernova per second explode somewhere

in our universe.

If we could hear it,

it would be popping like a bag of popcorn.

Now, if we fade out the supernovae,

it's not just brightness that changes.

Our sky is in constant motion.

This swarm of objects you see streaming across the sky

are asteroids as they orbit our sun,

and it's these changes and the motion

and it's the dynamics of the system

that allow us to build our models for our universe,

to predict its future and to explain its past.

But the telescopes we've used over the last decade

are not designed to capture the data at this scale.

The Hubble Space Telescope:

for the last 25 years it's been producing

some of the most detailed views

of our distant universe,

but if you tried to use the Hubble to create an image

of the sky, it would take 13 million individual images,

about 120 years to do this just once.

So this is driving us to new technologies

and new telescopes,

telescopes that can go faint

to look at the distant universe

but also telescopes that can go wide

to capture the sky as rapidly as possible,

telescopes like the Large Synoptic Survey Telescope,

or the LSST,

possibly the most boring name ever

for one of the most fascinating experiments

in the history of astronomy,

in fact proof, if you should need it,

that you should never allow a scientist or an engineer

to name anything, not even your children. (Laughter)

We're building the LSST.

We expect it to start taking data by the end of this decade.

I'm going to show you how we think

it's going to transform our views of the universe,

because one image from the LSST

is equivalent to 3,000 images

from the Hubble Space Telescope,

each image three and a half degrees on the sky,

seven times the width of the full moon.

Well, how do you capture an image at this scale?

Well, you build the largest digital camera in history,

using the same technology you find in the cameras in your cell phone

or in the digital cameras you can buy in the High Street,

but now at a scale that is five and a half feet across,

about the size of a Volkswagen Beetle,

where one image is three billion pixels.

So if you wanted to look at an image

in its full resolution, just a single LSST image,

it would take about 1,500 high-definition TV screens.

And this camera will image the sky,

taking a new picture every 20 seconds,

constantly scanning the sky

so every three nights, we'll get a completely new view

of the skies above Chile.

Over the mission lifetime of this telescope,

it will detect 40 billion stars and galaxies,

and that will be for the first time

we'll have detected more objects in our universe

than people on the Earth.

Now, we can talk about this

in terms of terabytes and petabytes

and billions of objects,

but a way to get a sense of the amount of data

that will come off this camera

is that it's like playing every TED Talk ever recorded

simultaneously, 24 hours a day,

seven days a week, for 10 years.

And to process this data means

searching through all of those talks

for every new idea and every new concept,

looking at each part of the video

to see how one frame may have changed

from the next.

And this is changing the way that we do science,

changing the way that we do astronomy,

to a place where software and algorithms

have to mine through this data,

where the software is as critical to the science

as the telescopes and the cameras that we've built.

Now, thousands of discoveries

will come from this project,

but I'm just going to tell you about two

of the ideas about origins and evolution

that may be transformed by our access

to data at this scale.

In the last five years, NASA has discovered

over 1,000 planetary systems

around nearby stars,

but the systems we're finding

aren't much like our own solar system,

and one of the questions we face is

is it just that we haven't been looking hard enough

or is there something special or unusual

about how our solar system formed?

And if we want to answer that question,

we have to know and understand

the history of our solar system in detail,

and it's the details that are crucial.

So now, if we look back at the sky,

at our asteroids that were streaming across the sky,

these asteroids are like the debris of our solar system.

The positions of the asteroids

are like a fingerprint of an earlier time

when the orbits of Neptune and Jupiter

were much closer to the sun,

and as these giant planets migrated through our solar system,

they were scattering the asteroids in their wake.

So studying the asteroids

is like performing forensics,

performing forensics on our solar system,

but to do this, we need distance,

and we get the distance from the motion,

and we get the motion because of our access to time.

So what does this tell us?

Well, if you look at the little yellow asteroids

flitting across the screen,

these are the asteroids that are moving fastest,

because they're closest to us, closest to Earth.

These are the asteroids we may one day

send spacecraft to, to mine them for minerals,

but they're also the asteroids that may one day

impact the Earth,

like happened 60 million years ago

with the extinction of the dinosaurs,

or just at the beginning of the last century,

when an asteroid wiped out

almost 1,000 square miles of Siberian forest,

or even just last year, as one burnt up over Russia,

releasing the energy of a small nuclear bomb.

So studying the forensics of our solar system

doesn't just tell us about the past,

it can also predict the future, including our future.

Now when we get distance,

we get to see the asteroids in their natural habitat,

in orbit around the sun.

So every point in this visualization that you can see

is a real asteroid.

Its orbit has been calculated from its motion across the sky.

The colors reflect the composition of these asteroids,

dry and stony in the center,

water-rich and primitive towards the edge,

water-rich asteroids which may have seeded

the oceans and the seas that we find on our planet

when they bombarded the Earth at an earlier time.

Because the LSST will be able to go faint

and not just wide,

we will be able to see these asteroids

far beyond the inner part of our solar system,

to asteroids beyond the orbits of Neptune and Mars,

to comets and asteroids that may exist

almost a light year from our sun.

And as we increase the detail of this picture,

increasing the detail by factors of 10 to 100,

we will be able to answer questions such as,

is there evidence for planets outside the orbit of Neptune,

to find Earth-impacting asteroids

long before they're a danger,

and to find out whether, maybe,

our sun formed on its own or in a cluster of stars,

and maybe it's this sun's stellar siblings

that influenced the formation of our solar system,

and maybe that's one of the reasons why solar systems like ours seem to be so rare.

Now, distance and changes in our universe —