0:00:08.200,0:00:10.200
I want to talk to you about something

0:00:10.400,0:00:11.687
kind of big.

0:00:13.774,0:00:15.909
We'll start here.

0:00:16.862,0:00:19.400
65 million years ago

0:00:19.790,0:00:22.405
the dinosaurs had a bad day.

0:00:23.093,0:00:25.399
(Laughter)

0:00:25.400,0:00:28.400
A chunk of rock six miles across,

0:00:28.800,0:00:31.179
moving something like 50 times

0:00:31.200,0:00:32.743
the speed of a rifle bullet,

0:00:32.764,0:00:34.458
slammed into the Earth.

0:00:34.479,0:00:36.845
It released its energy all at once,

0:00:36.866,0:00:38.989
and it was an explosion that was

0:00:39.057,0:00:40.442
mind-numbing.

0:00:40.463,0:00:43.357
If you took every nuclear weapon[br]ever built

0:00:43.378,0:00:45.199
at the height of the Cold War,

0:00:45.200,0:00:47.199
lumped them together and blew them up

0:00:47.200,0:00:48.843
at the same time,

0:00:48.864,0:00:50.864
that would be one one-millionth

0:00:50.885,0:00:53.636
of the energy released at that moment.

0:00:54.232,0:00:57.093
The dinosaurs had a really bad day.

0:00:57.803,0:00:58.822
Okay?

0:00:58.843,0:01:01.377
Now, a six-mile-wide rock is very large.

0:01:01.398,0:01:02.774
We all live here in Boulder.

0:01:02.795,0:01:05.503
If you look out your window[br]and you can see Long's Peak,

0:01:05.503,0:01:07.147
you're probably familiar with it.

0:01:07.147,0:01:08.524
Now, scoop up Long's Peak,

0:01:08.524,0:01:10.176
and put it out in space.

0:01:10.176,0:01:12.667
Take Meeker, Mt. Meeker.

0:01:12.667,0:01:15.370
Lump that in there,[br]and put that in space as well,

0:01:15.391,0:01:18.164
and Mt. Everest, and K2,

0:01:18.200,0:01:19.979
and the Indian peaks.

0:01:20.000,0:01:21.701
Then you're starting to get an idea

0:01:21.722,0:01:23.722
of how much rock[br]we're talking about, okay?

0:01:23.743,0:01:25.296
We know it was that big

0:01:25.317,0:01:27.868
because of the impact[br]it had and the crater it left.

0:01:27.889,0:01:30.379
It hit in what we now know as Yucatan,

0:01:30.400,0:01:31.917
the Gulf of Mexico.

0:01:31.938,0:01:33.425
You can see here,

0:01:33.446,0:01:36.066
there's the Yucatan Peninsula,[br]if you recognize Cozumel

0:01:36.087,0:01:37.288
off the east coast there.

0:01:37.309,0:01:39.988
Here is how big of a crater was left.

0:01:40.737,0:01:42.313
There we go.

0:01:42.979,0:01:44.275
It was huge.

0:01:44.296,0:01:46.918
To give you a sense of the scale,[br]okay, there you go.

0:01:46.939,0:01:49.156
The scale here is 50 miles on top,

0:01:49.179,0:01:50.934
a hundred kilometers on the bottom.

0:01:50.955,0:01:53.878
This thing was 300 kilometers across[br]- 200 miles -

0:01:53.899,0:01:56.228
an enormous crater that excavated out

0:01:56.249,0:01:59.249
vast amounts of earth[br]that splashed around the globe

0:01:59.876,0:02:02.140
and set fires all over the planet,

0:02:02.161,0:02:04.593
threw up enough dust to block out the sun.

0:02:04.614,0:02:07.614
It wiped out 75 percent[br]of all species on Earth.

0:02:08.723,0:02:11.453
Now, not all asteroids are that big.

0:02:11.744,0:02:13.744
Some of them are smaller.

0:02:13.842,0:02:16.712
Here is one that came in

0:02:16.733,0:02:18.733
over the United States

0:02:18.754,0:02:21.053
in October of 1992.

0:02:21.104,0:02:23.005
It came in on a Friday night.

0:02:23.026,0:02:24.251
Why is that important?

0:02:24.272,0:02:26.474
Because back then, video cameras

0:02:26.495,0:02:28.257
were just starting to become popular,

0:02:28.278,0:02:30.802
and people would bring them,[br]parents would bring them,

0:02:30.823,0:02:33.823
to their kids' football games[br]to film their kids play football.

0:02:33.936,0:02:36.069
And since this came in on a Friday,

0:02:36.090,0:02:38.148
they were able to get this great footage

0:02:38.169,0:02:40.169
of this thing breaking up as it came in

0:02:40.190,0:02:42.190
over West Virgina, Maryland, Pennsylvania

0:02:42.211,0:02:44.211
and New Jersey until it did that

0:02:44.232,0:02:46.232
to a car in New York.

0:02:46.253,0:02:47.407
(Laughter)

0:02:47.428,0:02:50.254
Now, this is not a 200-mile-wide crater,

0:02:50.706,0:02:52.706
but then again you can see the rock

0:02:52.727,0:02:54.363
which is sitting right here,

0:02:54.384,0:02:55.775
about the size of a football,

0:02:55.796,0:02:58.116
that hit that car and did that damage.

0:02:58.137,0:03:00.137
Now this thing was probably about the size

0:03:00.157,0:03:02.003
of a school bus when it first came in.

0:03:02.024,0:03:04.024
It broke up through atmospheric pressure,

0:03:04.045,0:03:06.267
it crumbled,[br]and then the pieces fell apart

0:03:06.288,0:03:07.886
and did some damage.

0:03:07.907,0:03:10.259
Now, you wouldn't want that[br]falling on your foot

0:03:10.280,0:03:13.280
or your head,[br]because it would do that to it.

0:03:13.368,0:03:14.878
That would be bad.

0:03:14.899,0:03:16.799
But it won't wipe out, you know,

0:03:16.820,0:03:18.632
all life on Earth, so that's fine.

0:03:18.653,0:03:21.653
But it turns out, you don't need[br]something six miles across

0:03:22.185,0:03:23.593
to do a lot of damage.

0:03:23.614,0:03:25.894
There is a median point between tiny rock

0:03:25.915,0:03:27.915
and gigantic rock, and in fact,

0:03:27.936,0:03:30.936
if any of you have ever been[br]to near Winslow, Arizona,

0:03:31.070,0:03:33.224
there is a crater in the desert there

0:03:33.245,0:03:36.245
that is so iconic[br]that it is actually called Meteor Crater.

0:03:37.266,0:03:40.266
To give you a sense of scale,[br]this is about a mile wide.

0:03:40.287,0:03:43.287
If you look up at the top,[br]that's a parking lot,

0:03:43.534,0:03:46.426
and those are recreational vehicles[br]right there.

0:03:46.447,0:03:49.447
So it's about a mile across,[br]600 feet deep.

0:03:49.468,0:03:52.468
The object that formed this[br]was probably about

0:03:52.489,0:03:54.963
30 to 50 yards across,

0:03:54.984,0:03:57.984
so roughly the size[br]of Macky Auditorium here.

0:03:58.515,0:04:01.367
It came in at speeds that were tremendous,

0:04:01.388,0:04:03.648
slammed into the ground, blew up,

0:04:03.669,0:04:05.585
and exploded with the energy of roughly

0:04:05.606,0:04:07.606
a 20-megaton nuclear bomb -

0:04:07.627,0:04:09.111
a very hefty bomb.

0:04:09.132,0:04:11.174
This was 50,000 years ago,

0:04:11.200,0:04:14.190
so it may have wiped out[br]a few buffalo or antelope,

0:04:14.211,0:04:16.682
or something like that out in the desert,

0:04:16.702,0:04:18.579
but it probably would not have caused

0:04:18.600,0:04:20.434
global devastation.

0:04:20.454,0:04:22.455
It turns out that these things

0:04:22.476,0:04:25.476
don't have to hit the ground[br]to do a lot of damage.

0:04:25.653,0:04:27.894
Now, in 1908, over Siberia,

0:04:27.915,0:04:30.260
near the Tunguska region -[br]for those of you

0:04:30.281,0:04:32.808
who are Dan Aykroyd fans[br]and saw "Ghostbusters,"

0:04:32.829,0:04:35.449
when he talked about[br]the greatest cross-dimensional rift

0:04:35.469,0:04:38.469
since the Siberia blast[br]of 1909, where he got the date wrong,

0:04:38.948,0:04:40.656
but that's okay. (Laughter)

0:04:40.677,0:04:43.677
It was 1908. That's fine.[br]I can live with that.

0:04:43.698,0:04:45.450
(Laughter)

0:04:45.471,0:04:48.471
Another rock came[br]into the Earth's atmosphere

0:04:48.492,0:04:50.492
and this one blew up above the ground,

0:04:50.513,0:04:53.005
several miles up above[br]the surface of the Earth.

0:04:53.026,0:04:54.799
The heat from the explosion

0:04:54.820,0:04:57.378
set fire to the forest below it,

0:04:58.296,0:05:01.291
and then the shock wave came down[br]and knocked down trees

0:05:01.312,0:05:04.312
for hundreds of square miles, okay?

0:05:04.333,0:05:06.333
This did a huge amount of damage.

0:05:06.354,0:05:08.609
And again, this was a rock[br]probably roughly

0:05:08.630,0:05:11.124
the size of this auditorium[br]that we're sitting in.

0:05:11.145,0:05:13.145
In Meteor Crater it was made of metal,

0:05:13.166,0:05:14.418
and metal is much tougher,

0:05:14.439,0:05:15.807
so it made it to the ground.

0:05:15.828,0:05:18.188
The one over Tunguska [br]was probably made of rock,

0:05:18.209,0:05:19.656
and that's much more crumbly,

0:05:19.677,0:05:21.077
so it blew up in the air.

0:05:21.098,0:05:25.061
Either way, these [br]are tremendous explosions, 20 megatons.

0:05:25.620,0:05:27.521
Now, when these things blow up,

0:05:27.542,0:05:31.291
they're not going to do [br]global ecological damage.

0:05:31.312,0:05:34.267
They're not going to do something[br]like the dinosaur-killer did.

0:05:34.288,0:05:35.632
They're just not big enough.

0:05:35.653,0:05:38.497
But they will do global economic damage,

0:05:38.518,0:05:41.069
because they don't have to hit,[br]necessarily,

0:05:41.090,0:05:42.632
to do this kind of damage.

0:05:42.653,0:05:45.307
They don't have to do global devastation.

0:05:45.328,0:05:47.018
If one of these things were to hit

0:05:47.039,0:05:49.164
pretty much anywhere,[br]it would cause a panic.

0:05:49.164,0:05:51.613
But if it came over a city,[br]an important city -

0:05:51.634,0:05:53.926
not that any city is more[br]important than others,

0:05:53.926,0:05:55.871
but some of them we depend on them more

0:05:55.871,0:05:57.299
on the global economic basis -

0:05:57.320,0:06:00.319
that could do[br]a huge amount of damage to us

0:06:00.340,0:06:02.339
as a civilization.

0:06:02.360,0:06:06.045
So, now that I've scared[br]the crap out of you...

0:06:06.066,0:06:07.331
(Laughter)

0:06:07.352,0:06:09.351
what can we do about this?[br]All right?

0:06:09.372,0:06:11.275
This is a potential threat.

0:06:11.296,0:06:14.505
Let me note that we have not had[br]a giant impact

0:06:14.526,0:06:16.775
like the dinosaur-killer[br]for 65 million years.

0:06:16.796,0:06:18.315
They're very rare.

0:06:18.336,0:06:20.474
The smaller ones happen more often,

0:06:20.495,0:06:23.156
but probably on the order of a millennium,

0:06:23.177,0:06:26.347
every few centuries[br]or every few thousand years,

0:06:26.368,0:06:28.458
but it's still something to be aware of.

0:06:28.479,0:06:29.982
Well, what do we do about them?

0:06:30.003,0:06:32.212
The first thing we have to do[br]is find them.

0:06:32.233,0:06:35.659
This is an image of an asteroid[br]that passed us in 2009.

0:06:36.421,0:06:38.275
It's right here.

0:06:38.295,0:06:41.386
And this is supposed to be animated,[br]so, it's okay though.

0:06:41.407,0:06:43.999
But you can see that it's extremely faint.

0:06:44.020,0:06:46.540
I don't even know if you can see that[br]in the back row.

0:06:46.540,0:06:47.704
These are just stars.

0:06:47.725,0:06:50.571
This is a rock that was about[br]30 yards across,

0:06:50.592,0:06:52.688
so roughly the size[br]of the ones that blew up

0:06:52.708,0:06:55.399
over Tunguska and hit Arizona[br]50,000 years ago.

0:06:55.380,0:06:56.940
These things are faint.

0:06:56.961,0:06:59.200
They're hard to see,[br]and the sky is really big.

0:06:59.221,0:07:00.961
We have to find these things first.

0:07:01.051,0:07:03.242
Well the good news is,[br]we're looking for them.

0:07:03.263,0:07:05.520
NASA has devoted money to this.

0:07:05.541,0:07:07.105
The National Science Foundation,

0:07:07.105,0:07:09.486
other countries are very[br]interested in doing this.

0:07:09.486,0:07:12.329
We're building telescopes [br]that are looking for the threat.

0:07:12.329,0:07:14.940
That's a great first step,[br]but what's the second step?

0:07:14.961,0:07:17.537
The second step is that we see[br]one heading toward us,

0:07:17.558,0:07:18.614
we have to stop it.

0:07:18.614,0:07:19.834
What do we do?

0:07:19.834,0:07:22.264
You've probably heard [br]about the asteroid Apophis.

0:07:22.264,0:07:24.196
If you haven't yet, you will.

0:07:24.217,0:07:26.886
If you've heard about[br]the Mayan 2012 apocalypse,

0:07:26.907,0:07:28.680
you're going to hear about Apophis,

0:07:28.680,0:07:32.040
because you're keyed in[br]to all the doomsday networks anyway.

0:07:33.463,0:07:36.632
Apophis is an asteroid[br]that was discovered in 2004.

0:07:36.653,0:07:39.355
It's roughly 250 yards across,

0:07:39.376,0:07:41.375
so it's pretty big - big size, you know,

0:07:41.396,0:07:42.959
bigger than a football stadium -

0:07:42.959,0:07:46.251
and it's going to pass by the Earth[br]in April of 2029.

0:07:46.272,0:07:48.037
And it's going to pass us so close

0:07:48.058,0:07:50.128
that it's actually[br]going to come underneath

0:07:50.128,0:07:51.767
our weather satellites.

0:07:51.788,0:07:54.061
The Earth's gravity[br]is going to bend the orbit

0:07:54.082,0:07:56.870
of this thing so much[br]that if it's just right,

0:07:56.891,0:07:59.474
if it passes through this region of space,

0:07:59.495,0:08:02.545
this kidney bean-shaped region[br]called the keyhole,

0:08:02.850,0:08:04.648
the Earth's gravity will bend it

0:08:04.669,0:08:06.505
just enough that seven years later

0:08:06.526,0:08:09.029
on April 13, which is a Friday, I'll note,

0:08:09.050,0:08:11.513
in the year 2036... (Laughter)

0:08:11.534,0:08:13.878
- you can't plan that kind of stuff -

0:08:13.899,0:08:15.791
Apophis is going to hit us.

0:08:15.812,0:08:17.894
And it's 250 meters across,

0:08:17.915,0:08:20.077
so it would do unbelievable damage.

0:08:20.098,0:08:22.063
Now the good news is that the odds of it

0:08:22.063,0:08:23.902
actually passing through this keyhole

0:08:23.902,0:08:26.758
and hitting us next go-around[br]are one in a million, roughly

0:08:26.758,0:08:27.784
very, very low odds,

0:08:27.784,0:08:29.824
so I personally[br]am not lying awake at night

0:08:29.824,0:08:31.160
worrying about this at all.

0:08:31.160,0:08:32.897
I don't think Apophis is a problem.

0:08:32.897,0:08:35.291
In fact, Apophis[br]is a blessing in disguise,

0:08:35.312,0:08:38.049
because it woke us up[br]to the dangers of these things.

0:08:38.070,0:08:40.401
This thing was discovered [br]just a few years ago

0:08:40.401,0:08:42.277
and could hit us a few years from now.

0:08:42.277,0:08:45.692
It won't, but it gives us a chance[br]to study these kinds of asteroids.

0:08:45.713,0:08:48.331
We didn't really necessarily understand[br]these keyholes,

0:08:48.352,0:08:49.863
and now we do and it turns out

0:08:49.884,0:08:53.902
that's really important, because[br]how do you stop an asteroid like this?

0:08:53.923,0:08:55.209
Well, let me ask you,

0:08:55.209,0:08:57.938
what happens if you're standing[br]in the [middle of] the road

0:08:57.938,0:08:59.235
and a car's headed for you?

0:08:59.235,0:09:00.618
What do you do?[br]You do this.

0:09:00.618,0:09:02.386
Right? Move. The car goes past you.

0:09:02.407,0:09:04.731
But we can't move the Earth,[br]at least not easily,

0:09:04.731,0:09:06.611
but we can move a small asteroid.

0:09:06.632,0:09:08.841
And it turns out, we've even done it.

0:09:08.862,0:09:11.667
In the year 2005, NASA launched a probe

0:09:11.688,0:09:14.532
called Deep Impact, which slammed into -

0:09:14.553,0:09:17.460
slammed a piece of itself[br]into the nucleus of a comet.

0:09:17.481,0:09:19.480
Comets are very much like asteroids.

0:09:19.501,0:09:21.650
The purpose wasn't to push it[br]out of the way.

0:09:21.650,0:09:24.077
The purpose was to make[br]a crater to excavate

0:09:24.098,0:09:26.076
the material and see what was underneath

0:09:26.076,0:09:29.047
the surface of this comet,[br]which we learned quite a bit about.

0:09:29.047,0:09:31.164
We did move the comet a little tiny bit,

0:09:31.185,0:09:33.184
not very much, but that wasn't the point.

0:09:33.205,0:09:35.093
However, think about this.

0:09:35.114,0:09:36.855
This thing is orbiting the Sun

0:09:36.876,0:09:39.339
at 10 miles per second,[br]20 miles per second.

0:09:39.360,0:09:42.101
We shot a space probe[br]at it and hit it. Okay?

0:09:42.138,0:09:44.974
Imagine how hard that must be,[br]and we did it.

0:09:44.995,0:09:46.601
That means we can do it again.

0:09:46.622,0:09:49.339
If we see[br]an asteroid that's coming toward us

0:09:49.360,0:09:50.902
and it's headed right for us,

0:09:50.923,0:09:53.839
and we have two years to go, boom![br]We hit it.

0:09:53.878,0:09:56.831
You can try to - you know, [br]if you watch the movies,

0:09:57.271,0:09:58.472
you might think about,

0:09:58.472,0:10:00.331
why don't we use a nuclear weapon?

0:10:00.331,0:10:03.241
It's like, well, you can try that,[br]but the problem is timing.

0:10:03.241,0:10:05.191
You shoot a nuclear weapon at this thing,

0:10:05.191,0:10:07.450
you have to blow it up[br]within a few milliseconds

0:10:07.450,0:10:09.445
of tolerance or else you'll just miss it.

0:10:09.445,0:10:11.741
And there are a lot of other problems[br]with that.

0:10:11.741,0:10:12.762
It's very hard to do.

0:10:12.762,0:10:15.019
But just hitting something?[br]That's pretty easy.

0:10:15.019,0:10:16.530
I think even NASA can do that,

0:10:16.530,0:10:18.529
and they proved that they can. (Laughter)

0:10:18.529,0:10:21.078
The problem is, what happens[br]if you hit this asteroid,

0:10:21.078,0:10:22.388
you've changed the orbit,

0:10:22.388,0:10:24.468
you measure the orbit[br]and then you find out,

0:10:24.468,0:10:26.497
oh, yeah, we just pushed[br]it into a keyhole,

0:10:26.497,0:10:28.687
and now it's going to hit[br]us in three years.

0:10:28.687,0:10:30.210
Well, my opinion is, fine. Okay?

0:10:30.210,0:10:32.616
It's not hitting us in six months.[br]That's good.

0:10:32.637,0:10:35.624
Now we have three years[br]to do something else.

0:10:35.645,0:10:37.148
And you can hit it again.

0:10:37.169,0:10:38.473
That's kind of ham-fisted.

0:10:38.473,0:10:41.216
You might just push it into [br]a third keyhole or whatever,

0:10:41.216,0:10:42.423
so you don't do that.

0:10:42.423,0:10:45.180
And this is the part,[br]it's the part I just love.

0:10:45.501,0:10:47.500
(Laughter)

0:10:47.834,0:10:49.918
After the big macho "Rrrrrrr BAM!

0:10:49.939,0:10:52.198
We're gonna hit this thing[br]in the face,"

0:10:52.199,0:10:55.198
then we bring in the velvet gloves.

0:10:55.198,0:10:57.111
(Laughter)

0:10:57.111,0:10:59.839
There's a group of scientists,[br]engineers and astronauts

0:10:59.839,0:11:02.267
and they call themselves[br]The B612 Foundation.

0:11:02.267,0:11:04.659
For those of you who've read[br]"The Little Prince,"

0:11:04.659,0:11:06.510
you understand that reference, I hope.

0:11:06.510,0:11:09.165
The little prince who lived[br]on an asteroid, called B612.

0:11:09.165,0:11:11.075
These are smart guys - men and women -

0:11:11.075,0:11:13.363
astronauts, like I said, engineers.

0:11:13.363,0:11:16.267
Rusty Schweickart, who was[br]an Apollo 9 astronaut, is on this.

0:11:16.288,0:11:18.442
Dan Durda, my friend who made this image,

0:11:18.463,0:11:21.228
works here at Southwest Research Institute[br]in Boulder,

0:11:21.249,0:11:22.624
on Walnut Street.

0:11:22.645,0:11:24.179
He created this image for this,

0:11:24.179,0:11:27.037
and he's actually one of the astronomers[br]who works for them.

0:11:27.037,0:11:29.449
If we see an asteroid[br]that's going to hit the Earth

0:11:29.449,0:11:30.955
and we have enough time,

0:11:30.976,0:11:33.368
we can hit it to move it[br]into a better orbit.

0:11:33.389,0:11:35.852
But then what we do is we launch

0:11:35.873,0:11:38.225
a probe that has to weigh a ton or two.

0:11:38.246,0:11:41.101
It doesn't have to be[br]huge - couple of tons, not that big -

0:11:41.122,0:11:42.974
and you park it near the asteroid.

0:11:42.995,0:11:44.053
You don't land on it,

0:11:44.053,0:11:46.331
because these things [br]are tumbling end over end.

0:11:46.331,0:11:47.876
It's very hard to land on them.

0:11:47.876,0:11:49.078
Instead you get near it.

0:11:49.078,0:11:51.307
The gravity of the asteroid[br]pulls on the probe,

0:11:51.307,0:11:53.373
and the probe[br]has a couple of tons of mass.

0:11:53.373,0:11:55.156
It has a little tiny bit of gravity,

0:11:55.177,0:11:58.355
but it's enough[br]that it can pull the asteroid,

0:11:58.376,0:12:00.743
and you have your rockets set up,[br]so you can -

0:12:00.764,0:12:03.529
oh, you can barely see it here,[br]but there's rocket plumes -

0:12:03.529,0:12:06.624
and you basically, these guys[br]are connected by their own gravity,

0:12:06.624,0:12:08.585
and if you move the probe very slowly,

0:12:08.606,0:12:11.894
very, very gently,[br]you can very easily

0:12:11.915,0:12:14.914
finesse that rock into a safe orbit.

0:12:14.935,0:12:16.935
You can even put in orbit around the Earth

0:12:16.956,0:12:19.853
where we could mine it, [br]although that's a whole other thing.

0:12:19.853,0:12:21.918
I won't go into that.[br](Laughter)

0:12:21.939,0:12:23.938
But we'd be rich!

0:12:23.959,0:12:26.959
(Laughter)

0:12:29.152,0:12:31.151
So think about this, right?

0:12:31.850,0:12:34.291
There are these giant rocks [br]flying out there,

0:12:34.312,0:12:37.003
and they're hitting us,[br]and they're doing damage to us,

0:12:37.003,0:12:38.820
but we've figured out how to do this,

0:12:38.820,0:12:40.857
and all the pieces[br]are in place to do this.

0:12:40.878,0:12:44.032
We have astronomers[br]with telescopes looking for them.

0:12:44.053,0:12:45.246
We have smart people,

0:12:45.267,0:12:47.843
very, very smart people, [br]who are concerned about this

0:12:47.843,0:12:49.745
and figuring out how to fix the problem,

0:12:49.766,0:12:51.682
and we have the technology to do this.

0:12:51.703,0:12:54.448
This probe actually[br]can't use chemical rockets.

0:12:54.448,0:12:57.118
Chemical rockets provide[br]too much thrust, too much push.

0:12:57.146,0:12:58.705
The probe would just shoot away.

0:12:58.726,0:13:00.726
We invented something called an ion drive,

0:13:00.747,0:13:03.553
which is a very, very,[br]very low-thrust engine.

0:13:03.574,0:13:06.775
It generates the force[br]a piece of paper would have on your hand,

0:13:06.799,0:13:08.005
incredibly light,

0:13:08.026,0:13:10.759
but it can run for months and years,

0:13:10.780,0:13:13.148
providing that very gentle push.

0:13:13.169,0:13:15.729
If anybody here is a fan[br]of the original "Star Trek,"

0:13:15.729,0:13:17.251
they ran across an alien ship

0:13:17.272,0:13:19.271
that had an ion drive, and Spock said,

0:13:19.292,0:13:21.317
"They're very technically sophisticated.

0:13:21.317,0:13:23.827
They're a hundred years ahead of us[br]with this drive."

0:13:23.827,0:13:25.876
Yeah, we have an ion drive now.[br](Laughter)

0:13:25.876,0:13:28.783
We don't have the Enterprise,[br]but we've got an ion drive now.

0:13:28.804,0:13:31.803
(Applause)

0:13:32.318,0:13:33.699
Spock.

0:13:33.720,0:13:35.874
(Laughter)

0:13:35.895,0:13:37.120
So...

0:13:38.604,0:13:42.437
that's the difference,[br]between us and the dinosaurs.

0:13:43.239,0:13:45.238
This happened to them.

0:13:45.430,0:13:47.359
It doesn't have to happen to us.

0:13:47.380,0:13:50.379
The difference[br]between the dinosaurs and us

0:13:50.400,0:13:52.605
is that we have a space program

0:13:52.626,0:13:54.351
and we can vote,

0:13:54.372,0:13:56.919
and so we can change our future.

0:13:56.940,0:13:58.363
(Laughter)

0:13:58.384,0:14:00.570
We have the ability to change our future.

0:14:00.591,0:14:02.443
65 million years from now,

0:14:02.464,0:14:04.340
we don't have to have our bones

0:14:04.361,0:14:06.360
collecting dust in a museum.

0:14:06.381,0:14:07.720
Thank you very much.

0:14:07.720,0:14:08.692
(Applause)