I am in search of another planet in the universe where life exists. I can't see this planet with my naked eyes or even with the most powerful telescopes we currently possess. But I know that it's there. And understanding contradictions that occur in nature will help us find it.
U potrazi sam za drugom planetom u univerzumu gde postoji život. Ovu planetu ne mogu videti golim okom ili čak najjačim teleskopima koje imamo trenutno. Ali znam da postoji. Razumevanje protivrečnosti koje se dešavaju u prirodi pomoći će nam da je pronađemo.
On our planet, where there's water, there's life. So we look for planets that orbit at just the right distance from their stars. At this distance, shown in blue on this diagram for stars of different temperatures, planets could be warm enough for water to flow on their surfaces as lakes and oceans where life might reside. Some astronomers focus their time and energy on finding planets at these distances from their stars. What I do picks up where their job ends. I model the possible climates of exoplanets. And here's why that's important: there are many factors besides distance from its star that control whether a planet can support life.
Na našoj planeti, gde ima vode, ima i života. Tako tražimo planete koje kruže na tačno određenoj udaljenosti od svojih zvezda. Na ovoj udaljenosti, prikazanoj u plavom na ovom crzežu za zvezde na različtim temperaturama, planete mogu biti dovoljno tople da na njihovim površinama teče voda u vidu jezera i okeana gde može biti života. Neki astronomi troše svoje vreme i energiju tražeći planete na ovoj udaljenosti od svojih zvezda. Ono što ja radim počinje tamo gde se njihov posao završava. Pravim moguće klimatske uslove egzoplaneta. Evo zašto je to bitno: postoji mnogo faktora, pored udaljenosti od zvezde, koji kontrolišu to da li planeta može da podrži život.
Take the planet Venus. It's named after the Roman goddess of love and beauty, because of its benign, ethereal appearance in the sky. But spacecraft measurements revealed a different story. The surface temperature is close to 900 degrees Fahrenheit, 500 Celsius. That's hot enough to melt lead. Its thick atmosphere, not its distance from the sun, is the reason. It causes a greenhouse effect on steroids, trapping heat from the sun and scorching the planet's surface. The reality totally contradicted initial perceptions of this planet. From these lessons from our own solar system, we've learned that a planet's atmosphere is crucial to its climate and potential to host life.
Uzmimo planetu Veneru. Ime je dobila po rimskoj boginji ljubavi i lepote, zbog svoje benigne, eterične pojave. Ali merenja svemirskih letelica otkrila su drugačiju priču. Površinska temperatura iznosi blizu 900 stepeni farenhajta, odnosno 500 celzijusa. To je dovoljno vrelo da istopi olovo. Razlog se nalazi u gustoj atmosferi, a ne u njenoj udaljenosti od Sunca. Dobija se pojačan efekat staklene bašte, toplota od Sunca se zarobljava i žari po površini planete. Stvarnost je bila potpuno drugačija od prvog utiska o ovoj planeti. Iz ovih lekcija iz našeg Sunčevog sistema, naučili smo da je atmosfera planete ključna za njene klimatske uslove i mogućnost održavanja života.
We don't know what the atmospheres of these planets are like because the planets are so small and dim compared to their stars and so far away from us. For example, one of the closest planets that could support surface water -- it's called Gliese 667 Cc -- such a glamorous name, right, nice phone number for a name -- it's 23 light years away. So that's more than 100 trillion miles. Trying to measure the atmospheric composition of an exoplanet passing in front of its host star is hard. It's like trying to see a fruit fly passing in front of a car's headlight. OK, now imagine that car is 100 trillion miles away, and you want to know the precise color of that fly.
Ne znamo kakve su atmosfere ovih planeta jer su planete tako male i slabe svetlosti u odnosu na svoje zvezde i toliko su daleko od nas. Na primer, jedna od najbližih planeta koje bi mogle da imaju vodu na površini - zove se Glise 667 Cc - baš spektakularno ime, zar ne, broj telefona umesto imena - udaljena je 23 svetlosne godine. To je više od 160 triliona kilometara. Kada biste pokušali da izmerite atmosferski sastav egzoplanete koja prolazi ispred svoje zvezde domaćina, to bi bilo veoma teško, kao kada biste pokušavali da vidite voćnu mušicu kako prolazi ispred svetala automobila. OK, sada zamislite da je taj automobil udaljen 160 triliona kilometara i želite da znate tačnu boju te voćne mušice.
So I use computer models to calculate the kind of atmosphere a planet would need to have a suitable climate for water and life.
Stoga koristim kompjuterske modele da izračunam kakva bi atmosfera bila potrebna planeti da ima povoljne klimatske uslove za vodu i život.
Here's an artist's concept of the planet Kepler-62f, with the Earth for reference. It's 1,200 light years away, and just 40 percent larger than Earth. Our NSF-funded work found that it could be warm enough for open water from many types of atmospheres and orientations of its orbit. So I'd like future telescopes to follow up on this planet to look for signs of life.
Evo umetničkog koncepta planete Kepler-62f, gde je Zemlja referentna tačka. Udaljena je 1200 svetlostnih godina i samo 40% je veća od Zemlje. U našem radu koji je finansirala Nacionalna fondacija za nauku otkrili smo da bi mogla da bude dovoljno topla za otvorenu vodu iz mnogih tipova atmosfera i orijentacije njene orbite. Volela bih da teleskopi u budućnosti prate ovu planetu i traže znakove života.
Ice on a planet's surface is also important for climate. Ice absorbs longer, redder wavelengths of light, and reflects shorter, bluer light. That's why the iceberg in this photo looks so blue. The redder light from the sun is absorbed on its way through the ice. Only the blue light makes it all the way to the bottom. Then it gets reflected back to up to our eyes and we see blue ice. My models show that planets orbiting cooler stars could actually be warmer than planets orbiting hotter stars. There's another contradiction -- that ice absorbs the longer wavelength light from cooler stars, and that light, that energy, heats the ice.
Led na površini planete takođe je bitan za klimu. Led upija duže, crvenije talasne dužine svetlosti i odbija kraću, plavlju svetlost. Zato ledeni breg na ovoj slici izgleda tako plavo. Crvenije svetlo od sunca upije se na putu do leda. Samo plava svetlost dopire do dna. Onda se odbija sve do naših očiju i vidimo plavi led. Moj model pokazuje da planete koje kruže oko hladnijih zvezda zapravo mogu biti toplije od planeta koje kruže oko toplijih zvezda. Postoji još jedna kontradikcija - taj led upija svetlost dužih talasnih dužina od hladnijih zvezda, i ta svetlost, ta energija zagreva led.
Using climate models to explore how these contradictions can affect planetary climate is vital to the search for life elsewhere.
Korišćenje klimatskih modela za istraživanje toga kako ove kontradikcije utiču na klimatske uslove planete ključno je za potragu života tamo negde.
And it's no surprise that this is my specialty. I'm an African-American female astronomer and a classically trained actor who loves to wear makeup and read fashion magazines, so I am uniquely positioned to appreciate contradictions in nature --
Nije čudno da sam stručna u ovome. Ja sam Afro-amerikanka astronom i glumica sa klasičnim obrazovanjem koja voli da se šminka i čita modne časopise tako da imam jedinstvenu poziciju gde cenim kontradikcije u prirodi -
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... and how they can inform our search for the next planet where life exists.
i kako mogu da pomognu našoj potrazi za sledećom planetom gde postoji život.
My organization, Rising Stargirls, teaches astronomy to middle-school girls of color, using theater, writing and visual art. That's another contradiction -- science and art don't often go together, but interweaving them can help these girls bring their whole selves to what they learn, and maybe one day join the ranks of astronomers who are full of contradictions, and use their backgrounds to discover, once and for all, that we are truly not alone in the universe.
Moja organizacija, Rising Stargirls, predajemo astronomiju obojenim devojčicama viših razreda osnovne škole koristeći pozorište, pisanu reč i vizuelnu umetnost. To je druga kontradikcija - nauka i umetnost često ne idu zajedno, ali njihovo kombinovanje može pomoći ovim devojčicama da se potpuno posvete tome što uče i možda se jednog dana pridruže astronomima koji su puni kontradikcija i koriste svoje poreklo da otkriju, jednom za svagda, da zaista nismo sami u univerzumu.
Thank you.
Hvala vam.
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