Adventures of an asteroid hunter
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0:01 - 0:04I am holding something remarkably old.
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0:04 - 0:07It is older than any human artifact,
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0:07 - 0:10older than life on Earth,
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0:10 - 0:13older than the continents
and the oceans between them. -
0:14 - 0:17This was formed
over four billion years ago -
0:17 - 0:19in the earliest days of the solar system
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0:19 - 0:21while the planets were still forming.
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0:21 - 0:24This rusty lump of nickel and iron
may not appear special, -
0:25 - 0:26but when it is cut open ...
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0:28 - 0:31you can see that it is different
from earthly metals. -
0:31 - 0:35This pattern reveals metallic crystals
that can only form out in space -
0:35 - 0:38where molten metal
can cool extremely slowly, -
0:38 - 0:40a few degrees every million years.
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0:41 - 0:43This was once part
of a much larger object, -
0:43 - 0:46one of millions left over
after the planets formed. -
0:46 - 0:48We call these objects asteroids.
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0:49 - 0:53Asteroids are our oldest
and most numerous cosmic neighbors. -
0:53 - 0:56This graphic shows near-Earth asteroids
orbiting around the Sun, -
0:56 - 0:57shown in yellow,
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0:57 - 0:59and swinging close to the Earth's orbit,
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0:59 - 1:00shown in blue.
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1:01 - 1:04The sizes of the Earth, Sun and asteroids
have been greatly exaggerated -
1:04 - 1:05so you can see them clearly.
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1:05 - 1:09Teams of scientists across the globe
are searching for these objects, -
1:09 - 1:11discovering new ones every day,
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1:11 - 1:13steadily mapping near-Earth space.
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1:13 - 1:15Much of this work is funded by NASA.
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1:16 - 1:20I think of the search for these asteroids
as a giant public works project, -
1:20 - 1:23but instead of building a highway,
we're charting outer space, -
1:23 - 1:26building an archive
that will last for generations. -
1:26 - 1:32These are the 1,556 near-Earth asteroids
discovered just last year. -
1:34 - 1:37And these are all of the known
near-Earth asteroids, -
1:37 - 1:41which at last count was 13,733.
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1:41 - 1:44Each one has been imaged, cataloged
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1:44 - 1:46and had its path
around the Sun determined. -
1:46 - 1:48Although it varies
from asteroid to asteroid, -
1:48 - 1:51the paths of most asteroids
can be predicted for dozens of years. -
1:51 - 1:55And the paths of some asteroids can be
predicted with incredible precision. -
1:55 - 1:58For example, scientists
at the Jet Propulsion Laboratory -
1:58 - 2:02predicted where the asteroid Toutatis
was going to be four years in advance -
2:02 - 2:04to within 30 kilometers.
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2:04 - 2:05In those four years,
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2:05 - 2:09Toutatis traveled 8.5 billion kilometers.
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2:09 - 2:11That's a fractional precision
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2:11 - 2:20of 0.000000004.
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2:20 - 2:22(Laughter)
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2:22 - 2:25Now, the reason I have
this beautiful asteroid fragment -
2:25 - 2:27is because, like all neighbors,
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2:27 - 2:29asteroids sometimes drop by unexpectedly.
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2:29 - 2:31(Laughter)
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2:33 - 2:34Three years ago today,
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2:34 - 2:38a small asteroid exploded
over the city of Chelyabinsk, Russia. -
2:38 - 2:40That object was about 19 meters across,
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2:40 - 2:42or about as big as a convenience store.
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2:43 - 2:46Objects of this size hit the Earth
every 50 years or so. -
2:48 - 2:5066 million years ago,
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2:50 - 2:52a much larger object hit the Earth,
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2:52 - 2:53causing a massive extinction.
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2:53 - 2:5775 percent of plant
and animal species were lost, -
2:57 - 2:59including, sadly, the dinosaurs.
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2:59 - 3:02That object was
about 10 kilometers across, -
3:02 - 3:06and 10 kilometers is roughly
the cruising altitude of a 747 jet. -
3:06 - 3:08So the next time you're in an airplane,
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3:08 - 3:12snag a window seat, look out
and imagine a rock so enormous -
3:12 - 3:14that resting on the ground,
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3:14 - 3:16it just grazes your wingtip.
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3:17 - 3:21It's so wide that it takes your plane
one full minute to fly past it. -
3:21 - 3:24That's the size of the asteroid
that hit the Earth. -
3:25 - 3:26It has only been within my lifetime
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3:26 - 3:30that asteroids have been considered
a credible threat to our planet. -
3:30 - 3:32And since then, there's been
a focused effort underway -
3:32 - 3:34to discover and catalog these objects.
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3:35 - 3:37I am lucky enough
to be part of this effort. -
3:37 - 3:41I'm part of a team of scientists
that use NASA's NEOWISE telescope. -
3:41 - 3:44Now, NEOWISE was not
designed to find asteroids. -
3:44 - 3:48It was designed to orbit the earth
and look far beyond our solar system -
3:48 - 3:51to seek out the coldest stars
and the most luminous galaxies. -
3:51 - 3:55And it did that very well
for its designed lifetime of seven months. -
3:56 - 3:59But today, six years later,
it's still going. -
3:59 - 4:02We've repurposed it
to discover and study asteroids. -
4:02 - 4:04And although it's
a wonderful little space robot, -
4:04 - 4:06these days it's kind of like a used car.
-
4:07 - 4:10The cryogen that used to refrigerate
its sensors is long gone, -
4:10 - 4:12so we joke that
its air-conditioning is broken. -
4:12 - 4:17It's got 920 million miles
on the odometer, -
4:17 - 4:18but it still runs great
-
4:18 - 4:22and reliably takes a photograph
of the sky every 11 seconds. -
4:22 - 4:25It's taken 23 photos
since I began speaking to you. -
4:26 - 4:28One of the reasons NEOWISE is so valuable
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4:28 - 4:31is that it sees the sky
in the thermal infrared. -
4:31 - 4:34That means that instead of seeing
the sunlight that asteroids reflect, -
4:34 - 4:36NEOWISE sees the heat that they emit.
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4:36 - 4:40This is a vital capability
since some asteroids are as dark as coal -
4:40 - 4:43and can be difficult or impossible
to spot with other telescopes. -
4:43 - 4:46But all asteroids, light or dark,
shine brightly for NEOWISE. -
4:49 - 4:52Astronomers are using
every technique at their disposal -
4:52 - 4:54to discover and study asteroids.
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4:54 - 4:57In 2010, a historic milestone was reached.
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4:57 - 5:01The community, together, discovered
over 90 percent of asteroids -
5:01 - 5:03bigger than one kilometer across --
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5:03 - 5:06objects capable
of massive destruction to Earth. -
5:06 - 5:07But the job's not done yet.
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5:08 - 5:12An object 140 meters or bigger
could decimate a medium-sized country. -
5:12 - 5:16So far, we've only found
25 percent of those. -
5:16 - 5:20We must keep searching the sky
for near-Earth asteroids. -
5:20 - 5:22We are the only species
able to understand calculus -
5:22 - 5:24or build telescopes.
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5:24 - 5:26We know how to find these objects.
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5:26 - 5:28This is our responsibility.
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5:28 - 5:32If we found a hazardous asteroid
with significant early warning, -
5:32 - 5:34we could nudge it out of the way.
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5:34 - 5:37Unlike earthquakes, hurricanes
or volcanic eruptions, -
5:37 - 5:40an asteroid impact
can be precisely predicted -
5:40 - 5:41and prevented.
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5:41 - 5:44What we need to do now
is map near-Earth space. -
5:44 - 5:46We must keep searching the sky.
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5:46 - 5:48Thank you.
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5:48 - 5:53(Applause)
- Title:
- Adventures of an asteroid hunter
- Speaker:
- Carrie Nugent
- Description:
-
TED Fellow Carrie Nugent is an asteroid hunter -- part of a group of scientists working to discover and catalog our oldest and most numerous cosmic neighbors. Why keep an eye out for asteroids? In this short, fact-filled talk, Nugent explains how their awesome impacts have shaped our planet -- and how finding them at the right time could mean nothing less than saving life on Earth.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TEDTalks
- Duration:
- 08:09
Brian Greene edited English subtitles for Adventures of an asteroid hunter | ||
Brian Greene edited English subtitles for Adventures of an asteroid hunter | ||
Brian Greene approved English subtitles for Adventures of an asteroid hunter | ||
Brian Greene edited English subtitles for Adventures of an asteroid hunter | ||
Brian Greene edited English subtitles for Adventures of an asteroid hunter | ||
Joanna Pietrulewicz accepted English subtitles for Adventures of an asteroid hunter | ||
Joanna Pietrulewicz edited English subtitles for Adventures of an asteroid hunter | ||
Joanna Pietrulewicz edited English subtitles for Adventures of an asteroid hunter |