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TEDGlobal 2011

Lucianne Walkowicz: Finding planets around other stars

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How do we find planets -- even habitable planets -- around other stars? By looking for tiny dimming as a planet passes in front of its sun, TED Fellow Lucianne Walkowicz and the Kepler mission have found some 1,200 potential new planetary systems. With new techniques, they may even find ones with the right conditions for life.

- Stellar astronomer
Lucianne Walkowicz works on NASA's Kepler mission, studying starspots and "the tempestuous tantrums of stellar flares." Full bio

Planetary systems outside our own
00:15
are like distant cities whose lights we can see twinkling,
00:17
but whose streets we can't walk.
00:20
By studying those twinkling lights though,
00:23
we can learn about how stars and planets interact
00:25
to form their own ecosystem
00:28
and make habitats that are amenable to life.
00:30
In this image of the Tokyo skyline,
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I've hidden data
00:35
from the newest planet-hunting space telescope on the block,
00:37
the Kepler Mission.
00:39
Can you see it?
00:41
There we go.
00:43
This is just a tiny part of the sky the Kepler stares at,
00:45
where it searches for planets
00:48
by measuring the light from over 150,000 stars,
00:50
all at once, every half hour,
00:53
and very precisely.
00:55
And what we're looking for
00:57
is the tiny dimming of light
00:59
that is caused by a planet passing in front of one of these stars
01:01
and blocking some of that starlight from getting to us.
01:04
In just over two years of operations,
01:07
we've found over 1,200
01:10
potential new planetary systems around other stars.
01:12
To give you some perspective,
01:15
in the previous two decades of searching,
01:17
we had only known about 400
01:20
prior to Kepler.
01:22
When we see these little dips in the light,
01:24
we can determine a number of things.
01:26
For one thing, we can determine that there's a planet there,
01:28
but also how big that planet is
01:30
and how far it is away from its parent star.
01:33
That distance is really important
01:36
because it tells us
01:38
how much light the planet receives overall.
01:40
And that distance and knowing that amount of light is important
01:42
because it's a little like you or I sitting around a campfire:
01:45
You want to be close enough to the campfire so that you're warm,
01:48
but not so close
01:50
that you're too toasty and you get burned.
01:52
However, there's more to know about your parent star
01:54
than just how much light you receive overall.
01:57
And I'll tell you why.
01:59
This is our star. This is our Sun.
02:01
It's shown here in visible light.
02:04
That's the light that you can see with your own human eyes.
02:06
You'll notice that it looks pretty much
02:08
like the iconic yellow ball --
02:10
that Sun that we all draw when we're children.
02:12
But you'll notice something else,
02:14
and that's that the face of the Sun
02:16
has freckles.
02:18
These freckles are called sunspots,
02:20
and they are just one of the manifestations
02:22
of the Sun's magnetic field.
02:24
They also cause the light from the star to vary.
02:26
And we can measure this
02:29
very, very precisely with Kepler and trace their effects.
02:31
However, these are just the tip of the iceberg.
02:34
If we had UV eyes or X-ray eyes,
02:37
we would really see
02:40
the dynamic and dramatic effects
02:42
of our Sun's magnetic activity --
02:44
the kind of thing that happens on other stars as well.
02:46
Just think, even when it's cloudy outside,
02:49
these kind of events are happening
02:51
in the sky above you all the time.
02:53
So when we want to learn whether a planet is habitable,
02:57
whether it might be amenable to life,
03:00
we want to know not only how much total light it receives
03:02
and how warm it is,
03:04
but we want to know about its space weather --
03:06
this high-energy radiation,
03:09
the UV and the X-rays
03:11
that are created by its star
03:13
and that bathe it in this bath of high-energy radiation.
03:15
And so, we can't really look
03:18
at planets around other stars
03:20
in the same kind of detail
03:22
that we can look at planets in our own solar system.
03:24
I'm showing here Venus, Earth and Mars --
03:27
three planets in our own solar system that are roughly the same size,
03:29
but only one of which
03:32
is really a good place to live.
03:34
But what we can do in the meantime
03:36
is measure the light from our stars
03:38
and learn about this relationship
03:41
between the planets and their parent stars
03:43
to suss out clues
03:45
about which planets might be good places
03:47
to look for life in the universe.
03:49
Kepler won't find a planet
03:51
around every single star it looks at.
03:53
But really, every measurement it makes
03:55
is precious,
03:57
because it's teaching us about the relationship
03:59
between stars and planets,
04:01
and how it's really the starlight
04:03
that sets the stage
04:05
for the formation of life in the universe.
04:07
While it's Kepler the telescope, the instrument that stares,
04:09
it's we, life, who are searching.
04:12
Thank you.
04:15
(Applause)
04:17

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About the speaker:

Lucianne Walkowicz - Stellar astronomer
Lucianne Walkowicz works on NASA's Kepler mission, studying starspots and "the tempestuous tantrums of stellar flares."

Why you should listen

Lucianne Walkowicz is an Astronomer at the Adler Planetarium in Chicago. She studies stellar magnetic activity and how stars influence a planet's suitability as a host for alien life. She is also an artist and works in a variety of media, from oil paint to sound. She got her taste for astronomy as an undergrad at Johns Hopkins, testing detectors for the Hubble Space Telescope’s new camera (installed in 2002). She also learned to love the dark stellar denizens of our galaxy, the red dwarfs, which became the topic of her PhD dissertation at University of Washington. Nowadays, she works on NASA’s Kepler mission, studying starspots and the tempestuous tantrums of stellar flares to understand stellar magnetic fields. She is particularly interested in how the high energy radiation from stars influences the habitability of planets around alien suns. Lucianne is also a leader in the Large Synoptic Survey Telescope, a new project that will scan the sky every night for 10 years to create a huge cosmic movie of our Universe.

More profile about the speaker
Lucianne Walkowicz | Speaker | TED.com