The flower-shaped starshade that might help us detect Earth-like planets | Jeremy Kasdin

Prevodilac: Vesna Savić Lektor: Mile Živković

The universe is teeming with planets.

Univerzum je preplavljen planetama.

I want us, in the next decade,

Ja želim da u narednoj deceniji

to build a space telescope that'll be able to image

napravimo teleskop koji će moći

an Earth about another star

da uslika drugu Zemlju koja orbitira oko svog Sunca

and figure out whether it can harbor life.

i koji će moći da vidi da li na toj planeti ima života.

My colleagues at the NASA Jet Propulsion Laboratory

Moje kolege i ja radimo u Nasinoj laboratoriji za mlazni pogon na Prinstonu,

at Princeton and I are working on technology

i trenutno razvijamo tehnologiju

that will be able to do just that in the coming years.

koja će narednih godina upravo to raditi.

Astronomers now believe that every star

Astronomi sada veruju da svaka zvezda

in the galaxy has a planet,

u galaksiji ima po jednu planetu,

and they speculate that up to one fifth of them

i pretpostavljaju da bar jedna petina njih

have an Earth-like planet

ima planetu sličnu Zemlji na kojoj može postojati život,

that might be able to harbor life,

but we haven't seen any of them.

ali nijednu još nismo videli.

We've only detected them indirectly.

Samo smo ih posredno detektovali.

This is NASA's famous picture of the pale blue dot.

Ovo je Nasina poznata slika blede plave tačke.

It was taken by the Voyager spacecraft in 1990,

Uslikao ju je svemirski brod Vojadžer 1990. godine

when they turned it around as it was exiting the solar system

kada su ga okrenuli dok je izlazio iz Sunčevog sistema

to take a picture of the Earth

kako bi slikao Zemlju s udaljenosti od 6 milijardi km.

from six billion kilometers away.

Hoću da isto tako slikamo planetu sličnu Zemlji

I want to take that

of an Earth-like planet about another star.

koja se kreće oko svoje zvezde.

Why haven't we done that? Why is that hard?

Zašto to još nismo uradili?

Zašto je to toliko teško?

Well to see, let's imagine we take

Zamislićemo da angažujemo svemirski teleskop Habl

the Hubble Space Telescope

and we turn it around and we move it out

i da ga okrenemo i izbacimo iz Marsove orbite.

to the orbit of Mars.

We'll see something like that,

Videli bismo nešto slično ovome, kao mutnjikavu sliku Zemlje,

a slightly blurry picture of the Earth,

because we're a fairly small telescope

jer je teleskop koji orbitira oko Marsa prilično mali.

out at the orbit of Mars.

Now let's move ten times further away.

Hajde da se udaljimo deset puta.

Here we are at the orbit of Uranus.

Evo nas u orbiti Urana.

It's gotten smaller, it's got less detail, less resolve.

Umanjena je, manje detaljna, ređa.

We can still see the little moon,

I dalje vidimo mali mesec,

but let's go ten times further away again.

ali hajde da se opet udaljimo deset puta.

Here we are at the edge of the solar system,

Evo nas na ivici Sunčevog sistema, na Kojperovom pojasu.

out at the Kuiper Belt.

Now it's not resolved at all.

Sada uopšte nije retka.

It's that pale blue dot of Carl Sagan's.

Liči na bledu plavu tačku Karla Sejgana.

But let's move yet again ten times further away.

Udaljimo se opet deset puta.

Here we are out at the Oort Cloud,

Evo nas na Ortovom oblaku, izvan Sunčevog sistema,

outside the solar system,

and we're starting to see the sun

i vidimo kako Sunce ulazi u vidno polje

move into the field of view

and get into where the planet is.

i smešta tamo gde je planeta.

One more time, ten times further away.

Još jednom, udaljavamo se deset puta.

Now we're at Alpha Centauri,

Evo nas na Alfi Kentauri, našoj najbližoj zvezdi,

our nearest neighbor star,

and the planet is gone.

i planeta se više ne vidi.

All we're seeing is the big beaming image of the star

Vidimo samo veliku blještavu sliku zvezde

that's ten billion times brighter than the planet,

koja je 10.000 puta sjajnija od planete,

which should be in that little red circle.

koja bi trebalo da se nalazi u tom crvenom kružiću.

That's what we want to see. That's why it's hard.

To želimo da vidimo. Zato je toliko teško.

The light from the star is diffracting.

Svetlost zvezde se difraktuje.

It's scattering inside the telescope,

Rasipa se u teleskopu

creating that very bright image

i stvara upravo tu blještavu sliku koja spira planetu.

that washes out the planet.

So to see the planet,

Da bismo videli planetu, moramo uraditi nešto po pitanju svetlosti.

we have to do something about all of that light.

We have to get rid of it.

Moramo je ukloniti.

I have a lot of colleagues working on

Puno mojih kolega radi na sjajnoj tehnologiji koja bi to postigla,

really amazing technologies to do that,

but I want to tell you about one today

ali ću vam sada pričati o onoj koju smatram najviše kul,

that I think is the coolest,

and probably the most likely to get us an Earth

i koja će nam najverovatnije u narednoj deceniji

in the next decade.

prikazati planetu srodnu Zemlji.

It was first suggested by Lyman Spitzer,

Rešenje je prvi predložio Lajman Spicer,

the father of the space telescope, in 1962,

otac svemirskog teleskopa, 1962. godine, inspirisan jednim pomračenjem.

and he took his inspiration from an eclipse.

You've all seen that. That's a solar eclipse.

Svi ste ovo videli.

The moon has moved in front of the sun.

To je pomračenje Sunca.

Mesec se postavio ispred Sunca

It blocks out most of the light

i blokira veliki deo svetlosti,

so we can see that dim corona around it.

tako da se oko njega vidi pomračena korona.

It would be the same thing if I put my thumb up

Isto bi se desilo kada bih podigao palac

and blocked that spotlight that's getting right in my eye,

i blokirao reflektor koji mi bije u oči,

I can see you in the back row.

te bih video vas u zadnjim redovima.

Well, what's going on?

Šta se, dakle, desi?

Well the moon

Mesec baca senku na Zemlju.

is casting a shadow down on the Earth.

We put a telescope or a camera in that shadow,

Kada stavimo teleskop ili kameru pod tu senku i pogledamo u Sunce

we look back at the sun,

and most of the light's been removed

svetlost nestaje i možemo da vidimo lep zamračen oblik u koroni.

and we can see that dim, fine structure

in the corona.

Spitzer's suggestion was we do this in space.

Spicer je predložio da isto uradimo i u svemiru.

We build a big screen, we fly it in space,

Da napravimo veliki štit, pošaljemo ga u svemir,

we put it up in front of the star,

postavimo ga ispred zvezde, blokiramo svetlost,

we block out most of the light,

we fly a space telescope in that shadow that's created,

pošaljemo svemirski teleskop u stvorenu senku, i eto ga!

and boom, we get to see planets.

Možemo da vidimo planete.

Well that would look something like this.

To bi izgledalo otprilike ovako.

So there's that big screen,

Eto tog platna, ali nema planeta

and there's no planets,

because unfortunately it doesn't actually work very well,

jer nažalost ne radi dobro,

because the light waves of the light and waves

zbog toga što svetlosni talasi difraktuju oko tog platna,

diffracts around that screen

the same way it did in the telescope.

isto kao u teleskopu.

It's like water bending around a rock in a stream,

Kao kada se voda u potoku preliva preko kamena.

and all that light just destroys the shadow.

Ta svetlost samo uništi senku.

It's a terrible shadow. And we can't see planets.

Senka je loša i ne možemo da vidimo planete od nje.

But Spitzer actually knew the answer.

Ali, Spicer je znao rešenje tog problema.

If we can feather the edges, soften those edges

Ako se ivice iseku, ublaže,

so we can control diffraction,

difrakcija se može kontrolisati

well then we can see a planet,

i onda možemo da vidimo planetu.

and in the last 10 years or so we've come up

Već oko 10 godina radimo

with optimal solutions for doing that.

na pravom rešenju za postizanje toga.

It looks something like that.

I ono izgleda otprilike ovako.

We call that our flower petal starshade.

Zovemo ga cvetni zvezdobran.

If we make the edges of those petals exactly right,

Ako ivice latica podesimo kako treba,

if we control their shape,

ako kontrolišemo njihov oblik,

we can control diffraction,

onda kontrolišemo i difrakciju,

and now we have a great shadow.

i dobijamo odličnu senku.

It's about 10 billion times dimmer than it was before,

Oko 10 milijardi puta je tamnija od prethodne,

and we can see the planets beam out just like that.

i planete se odjednom pojavljuju.

That, of course, has to be bigger than my thumb.

Taj branik, naravno, mora biti veći od mog palca.

That starshade is about

Zvezdobran je otprilike

the size of half a football field

veličine pola stadiona za američki fudbal

and it has to fly 50,000 kilometers away from the telescope

i mora da se udalji oko 50.000 km od teleskopa,

that has to be held right in its shadow,

da stoji u njegovoj senci kako bi se planete lepo videle.

and then we can see those planets.

This sounds formidable,

Ovo možda zvuči nedostižno,

but brilliant engineers, colleagues of mine at JPL,

ali genijalni inženjeri, moje kolege u Laboratoriji za mlazni pogon,

came up with a fabulous design for how to do that

smislile su spravu fantastičnog dizajna

and it looks like this.

i ona izgleda ovako.

It starts wrapped around a hub.

Umotana je oko točka.

It separates from the telescope.

Prvo se otisne od teleskopa.

The petals unfurl, they open up,

Latice se odmotaju, otvore,

the telescope turns around.

teleskop se okreće.

Then you'll see it flip and fly out

Sprava se onda okrene i udalji

that 50,000 kilometers away from the telescope.

50.000 km od teleskopa.

It's going to move in front of the star

Kada se namesti ispred zvezde - ovako - bacaće divnu senku.

just like that, creates a wonderful shadow.

Boom, we get planets orbiting about it.

I eto ga! Vidimo kako planete orbitiraju oko zvezde.

(Applause)

(Aplauz)

Thank you.

Hvala.

That's not science fiction.

Ovo nije naučna fantastika.

We've been working on this for the last five or six years.

Na ovome smo radili u poslednjih 5-6 godina.

Last summer, we did a really cool test

Prošlog leta smo sproveli veoma kul test

out in California at Northrop Grumman.

u kompaniji Nortrop Gruman, u Kaliforniji.

So those are four petals.

To su četiri latice

This is a sub-scale star shade.

umanjenog zvezdobrana.

It's about half the size of the one you just saw.

Otprilike je upola manji od prethodnog.

You'll see the petals unfurl.

Vidite kako se latice odmotavaju.

Those four petals were built by four undergraduates

Napravili su ih naši studenti

doing a summer internship at JPL.

na letnjoj praksi u Laboratoriji.

Now you're seeing it deploy.

Sad ćete videti kako radi.

Those petals have to rotate into place.

Latice moraju da dođu na svoje mesto.

The base of those petals

Baza latica svaki put mora da dođe na svoje mesto,

has to go to the same place every time

to within a tenth of a millimeter.

u milimetar.

We ran this test 16 times,

Test smo radili 16 puta

and 16 times it went into the exact same place

i svaki put su se postavile baš na svoje mesto,

to a tenth of a millimeter.

do u desetinu milimetra.

This has to be done very precisely,

To mora biti vrlo precizno,

but if we can do this, if we can build this technology,

i ako to uspemo, ako napravimo tu spravu,

if we can get it into space,

ako je pošaljemo u svemir,

you might see something like this.

možemo videti nešto poput ovoga.

That's a picture of one our nearest neighbor stars

Ovo je slika jedne od naših najbližih zvezda,

taken with the Hubble Space Telescope.

slikao ju je svemirski teleskop Habl.

If we can take a similar space telescope,

Ako sličan teleskop, samo malo veći,

slightly larger,

put it out there,

pošaljemo u svemir, oko njega ostavimo štit,

fly an occulter in front of it,

what we might see is something like that --

onda možemo videti ovako nešto -

that's a family portrait of our solar system -- but not ours.

to je porodični portret sunčevog sistema - ali ne našeg.

We're hoping it'll be someone else's solar system

Nadamo se da će to biti tuđi sistem,

as seen through an occulter,

viđen kroz štit, kroz takav zvezdobran.

through a starshade like that.

You can see Jupiter, you can see Saturn,

Vide se Jupiter, Saturn, Uran, Neptun,

Uranus, Neptune, and right there in the center,

next to the residual light

a tamo u centru, odmah pored ostatka svetlosti,

is that pale blue dot. That's Earth.

to je ona bleda plava tačka.

We want to see that, see if there's water,

To je Zemlja.

Hoćemo da vidimo ima li vode, kiseonika, ozona -

oxygen, ozone,

the things that might tell us that it could harbor life.

stvari koje bi nam rekle postoji li život.

I think this is the coolest possible science.

Mislim da je to nauka koja je najviše kul.

That's why I got into doing this,

Ja sam počeo da se bavim ovim poslom

because I think that will change the world.

zato što smatram da će to promeniti svet.

That will change everything when we see that.

To će promeniti sve - kad sve to vidimo.

Thank you.

Hvala.

(Applause)

(Aplauz)