So when you look out at the stars at night, it's amazing what you can see. It's beautiful. But what's more amazing is what you can't see, because what we know now is that around every star or almost every star, there's a planet, or probably a few.
Kur shikon yjet naten ajo qe mund te shohesh eshte e mrekullueshme. Eshte e bukur. Por, me mahnitese eshte ajo qe nuk shohim, sepse nga ato qe dime tani, rreth yjeve ose pothuajse cdo ylli, ndodhet nje planet, ose ndoshta disa.
So what this picture isn't showing you are all the planets that we know about out there in space. But when we think about planets, we tend to think of faraway things that are very different from our own. But here we are on a planet, and there are so many things that are amazing about Earth that we're searching far and wide to find things that are like that. And when we're searching, we're finding amazing things. But I want to tell you about an amazing thing here on Earth. And that is that every minute, 400 pounds of hydrogen and almost seven pounds of helium escape from Earth into space. And this is gas that is going off and never coming back. So hydrogen, helium and many other things make up what's known as the Earth's atmosphere. The atmosphere is just these gases that form a thin blue line that's seen here from the International Space Station, a photograph that some astronauts took. And this tenuous veneer around our planet is what allows life to flourish. It protects our planet from too many impacts, from meteorites and the like. And it's such an amazing phenomenon that the fact that it's disappearing should frighten you, at least a little bit.
Pra ajo qe kjo foto nuk po ju tregon jane te gjithe planetet qe ne dime qe jane ne hapesire. Mendojme rreth planeteve per gjera qe jane shume te ndryshme nga ai i joni. Pra ja ku jemi ne nje planet, dhe ka kaq shume fakte qe jane mahnitese per Token qe po i kerkojme gjere e gjate qe t'i gjejme. Dhe gjate kerkimeve, po gjejme gjera mahnitese. Por, une dua t'ju flas per nje fakt interesant ketu ne Toke. Kjo eshte se cdo minute, 200 kg hidrogjen, dhe pothuajse 3,5 kg helium largohen nga Toka per ne hapesire. Ky eshte gaz qe largohet dhe nuk kthehet me pas. Pra, hidrogjeni, heliumi dhe disa gjera te tjera perbejne ate qe quhet atmosfera e Tokes. Atmosfera jane thjeshte keto gazra, qe formojne nje shtrese te holle blu e shikuar ketu nga Stacioni Nderkombetar Hapesinor ku disa astronaute e fotografuan. Kjo mbulese e parendesishme ne planetin tone ben qe jeta te vazhdoje. Ajo e mbron planetin tone nga shume rreziqe, qe nga meteoritet dhe te tjera me rradhe. Eshte aq fenomen mahnites saqe fakti se po zhduket duhet t'ju frikesoje juve, paksa.
So this process is something that I study and it's called atmospheric escape. So atmospheric escape is not specific to planet Earth. It's part of what it means to be a planet, if you ask me, because planets, not just here on Earth but throughout the universe, can undergo atmospheric escape. And the way it happens actually tells us about planets themselves. Because when you think about the solar system, you might think about this picture here. And you would say, well, there are eight planets, maybe nine. So for those of you who are stressed by this picture, I will add somebody for you.
Pra, ky proces eshte ajo qe une studioj dhe quhet hollimi i atmosferes. Hollimi i atmosferes nuk eshte specifike vetem per Token. Sipas meje, eshte dicka qe u ndodh te gjitha planeteve sepse planetet, jo vetem ketu ne Toke por ne te gjithe universin, i nenshtrohen hollimit te atmosferes. Menyra sesi ndodh kjo na tregon ne rreth vete planeteve. Sepse kur mendon, rreth sistemit diellor, mund te mendosh si kjo fotoja ketu. Dhe mund te thuash, ne rregull, ka 8 planete, ose ndoshta 9. Keshtu qe per ata qe , jane shqetesuar nga kjo foto, po shtoj dicka per ju.
(Laughter)
(Te qeshura)
Courtesy of New Horizons, we're including Pluto. And the thing here is, for the purposes of this talk and atmospheric escape, Pluto is a planet in my mind, in the same way that planets around other stars that we can't see are also planets. So fundamental characteristics of planets include the fact that they are bodies that are bound together by gravity. So it's a lot of material just stuck together with this attractive force. And these bodies are so big and have so much gravity. That's why they're round. So when you look at all of these, including Pluto, they're round.
Fale dashamiresise se misionit te NASA, New Horizons, po perfshijme Plutonin. Ceshtja ketu qendron se, per qellimin e ketij fjalimi dhe hollimit te atmosferes, Plutoni eshte planet ne mendjen time, sic jane te gjitha planetet e tjera rreth yjeve qe ne nuk mund t'i shohim, qe gjithashtu jane planete. Karakteristike thelbesore e planeteve eshte fakti se ata jane trupa qe jane te lidhur se bashku nga graviteti. Pra eshte gjithe ai material, qe qendron i lidhur me kete force terheqese. Keta trupa jane kaq te medhenj dhe kane shume gravitet. Ja pse ata jane te rrumbullaket. Pra, kur i shikon te gjithe ata, perfshire edhe Plutonin, ata jane te rrumbullaket.
So you can see that gravity is really at play here. But another fundamental characteristic about planets is what you don't see here, and that's the star, the Sun, that all of the planets in the solar system are orbiting around. And that's fundamentally driving atmospheric escape. The reason that fundamentally stars drive atmospheric escape from planets is because stars offer planets particles and light and heat that can cause the atmospheres to go away. So if you think of a hot-air balloon, or you look at this picture of lanterns in Thailand at a festival, you can see that hot air can propel gasses upward. And if you have enough energy and heating, which our Sun does, that gas, which is so light and only bound by gravity, it can escape into space. And so this is what's actually causing atmospheric escape here on Earth and also on other planets -- that interplay between heating from the star and overcoming the force of gravity on the planet.
Pra mund te shikosh qe graviteti ka nje rol te rendesishem. Por nje tjeter karakterisetike thelbesore per planetet eshte ajo qe nuk shikohet ketu, dhe ky eshte ylli, Dielli, rreth te cilit rrotullohen gjithe planetet e sistemit diellor. Kjo arsye po shton kryesisht hollimin e atmosferes. Arsyeja kryesore se pse yjet nxisin hollimin e atmosferes nga planetet eshte sepse yjet u ofrojne planeteve grimca, drite dhe nxehtesi, qe mund te shkaktoje largimin e atmosferes. Nese mendon per nje balone me ajer te nxehte, ose shikoni kete foto me fanare ne nje festival ne Tajlande, mund te vereni se ajri i nxehte ve ne levizje gazrat perpjete. Dhe nese ke mjaftueshem energji dhe nxehtesi, te cilat Dielli i ka, ky gaz, i cili eshte shume i lehte dhe lidhet vetem nga graviteti, mund te largohet neper hapesire. Ajo qe aktualisht po shkakton hollimin e atmosferes ne Toke por edhe ne planetet e tjera gjithashtu-- eshte nderveprimi midis nxehtesise nga yjet dhe kapercimi i forces se gravitetit ne planet.
So I've told you that it happens at the rate of 400 pounds a minute for hydrogen and almost seven pounds for helium. But what does that look like? Well, even in the '80s, we took pictures of the Earth in the ultraviolet using NASA's Dynamic Explorer spacecraft. So these two images of the Earth show you what that glow of escaping hydrogen looks like, shown in red. And you can also see other features like oxygen and nitrogen in that white glimmer in the circle showing you the auroras and also some wisps around the tropics. So these are pictures that conclusively show us that our atmosphere isn't just tightly bound to us here on Earth but it's actually reaching out far into space, and at an alarming rate, I might add.
Iu thashe se kjo ndodh ne normen e 200 kg per min per hidrogjenin dhe pothuajse 3,5 kg per min per heliumin. Por si duket kjo? Ne vitet '80 ne kemi bere foto te Tokes te rrezeve ultraviolet duke perdorur sonden e NASA-s "Dynamic Explorer" Pra, keto dy imazhe te Tokes paraqesin se si digjet hidrogjeni kur largohet, i treguar me te kuqe. Mund te shikoni karakteristika te tjera si oksigjeni dhe nitrogjeni ne ate dritezen e bardhe rrethore qe na paraqesin aurorat dhe gjithashtu disa fije perreth tropikeve. Pra, keto jane foto qe perfundimisht na tregojne qe atmosfera jone nuk eshte thjesht e lidhur fort te planeti yne por aktualisht eshte duke u larguar ne hapesire, ne menyre alarmante, sipas meje.
But the Earth is not alone in undergoing atmospheric escape. Mars, our nearest neighbor, is much smaller than Earth, so it has much less gravity with which to hold on to its atmosphere. And so even though Mars has an atmosphere, we can see it's much thinner than the Earth's. Just look at the surface. You see craters indicating that it didn't have an atmosphere that could stop those impacts. Also, we see that it's the "red planet," and atmospheric escape plays a role in Mars being red. That's because we think Mars used to have a wetter past, and when water had enough energy, it broke up into hydrogen and oxygen, and hydrogen being so light, it escaped into space, and the oxygen that was left oxidized or rusted the ground, making that familiar rusty red color that we see.
Por nuk eshte vetem Toka qe po i nenshtrohet hollimit te atmosferes. Marsi, fqinji yne me i afert eshte shume me i vogel se Toka, keshtu qe ka shume me pak gravitet, me te cilin te mbaje atmosferen e tij. Pra, edhe pse Marsi ka nje atmosfere, shohim se shume me e holle se e Tokes. Vetem shikoni siperfaqen. Dallohen kratere qe tregojne se nuk ka patur nje atmosfere qe mund te ndalonte rreziqet. Gjithashtu, shikojme se eshte "planeti i kuq" dhe hollimi atmosferik luan nje rol qe Marsi te jete i kuq. Ne mendojme se Marsi ka patur nje te kaluar me lageshtire, dhe kur uji kishte energji te mjaftueshme, u nda ne hidrogjen dhe oksigjen, mirepo duke qene i lehte hidrogjeni u leshua per ne hapesire, dhe oksigjeni qe ngeli u oksidua ose ndryshku dheun, qe u kthye ne kete ngjyren e kuqe te ndryshkut qe shohim ne.
So it's fine to look at pictures of Mars and say that atmospheric escape probably happened, but NASA has a probe that's currently at Mars called the MAVEN satellite, and its actual job is to study atmospheric escape. It's the Mars Atmosphere and Volatile Evolution spacecraft. And results from it have already shown pictures very similar to what you've seen here on Earth. We've long known that Mars was losing its atmosphere, but we have some stunning pictures. Here, for example, you can see in the red circle is the size of Mars, and in blue you can see the hydrogen escaping away from the planet. So it's reaching out more than 10 times the size of the planet, far enough away that it's no longer bound to that planet. It's escaping off into space. And this helps us confirm ideas, like why Mars is red, from that lost hydrogen. But hydrogen isn't the only gas that's lost. I mentioned helium on Earth and some oxygen and nitrogen, and from MAVEN we can also look at the oxygen being lost from Mars. And you can see that because oxygen is heavier, it can't get as far as the hydrogen, but it's still escaping away from the planet. You don't see it all confined into that red circle.
Pranohet te shikosh fotot e Marsit dhe te thuash se ndoshta hollimi atmosferik ka ndodhur, por NASA ka nje sonde qe ndodhet ne Mars qe quhet sateliti MAVEN, ku puna e tij eshte te studioje hollimin e atmosferes. Eshte Atmosfera e Marsit dhe sonda Volatile Evolution. Gjetjet atje kane treguar foto qe jane shume te ngjashme me ato qe keni pare ketu ne Toke. E kemi ditur gjate qe Marsi po e humbiste atmosferen, por kemi disa foto shokuese. Per shembull, ketu, mund te shikoni ne rrethin e kuq madhesine e Marsit, dhe ne blu mund te shihni hidrogjenin qe largohet nga planeti. Pra, po arrin 10 fishin e madhesise se planetit, larg nga kufiri i ketij planeti. Po leshohet neper hapesire. Kjo na ndihmon te konfirmojme idete, si ajo pse Marsi nga humbja e hidrogjenit, eshte i kuq. Por nuk eshte hidrogjeni gazi i vetem qe po humb. Permenda heliumin ne Toke dhe pak oksigjen dhe nitrogjen, por nga MAVEN mund te verejme oksigjenin qe po largohet nga Marsi. Mund te shikoni se ngaqe oksigjeni eshte me i rende, nuk mund te largohet aq larg sa hidrogjeni por sidoqofte po largohet nga planeti. Nuk shihet te jete i teri i permbledhur ne ate rrethin e kuq.
So the fact that we not only see atmospheric escape on our own planet but we can study it elsewhere and send spacecraft allows us to learn about the past of planets but also about planets in general and Earth's future. So one way we actually can learn about the future is by planets so far away that we can't see. And I should just note though, before I go on to that, I'm not going to show you photos like this of Pluto, which might be disappointing, but that's because we don't have them yet. But the New Horizons mission is currently studying atmospheric escape being lost from the planet. So stay tuned and look out for that. But the planets that I did want to talk about are known as transiting exoplanets.
Pra fakti qe nuk shohim hollim atmosferik vetem ne Toke por mund ta studiojme kudo dhe te dergojme sonda na lejon te mesojme rreth te shkuares se planeteve por gjithashtu per planetet ne pergjithesi dhe per te ardhmen e Tokes. Nje menyre qe mund te mesojme per te ardhmen eshte nga planetet e larget qe ne nuk mund t'i shohim. Me duhet te permend se, para se te vazhdoj me kete, nuk kam per t'iu treguar foto si Plutoni, qe mund te duket zhgenjyese, por kjo sepse nuk i kemi akoma fotot. Por, misioni i New Horizons eshte qe te studioje hollimin atmosferik qe largohet nga planeti. Keshtu qe kini mendjen per kete. Planetet qe une dua te flas jane te njohur si ekzoplanetet.
So any planet orbiting a star that's not our Sun is called an exoplanet, or extrasolar planet. And these planets that we call transiting have the special feature that if you look at that star in the middle, you'll see that actually it's blinking. And the reason that it's blinking is because there are planets that are going past it all the time, and it's that special orientation where the planets are blocking the light from the star that allows us to see that light blinking. And by surveying the stars in the night sky for this blinking motion, we are able to find planets. This is how we've now been able to detect over 5,000 planets in our own Milky Way, and we know there are many more out there, like I mentioned.
Keshtu qe cdo planet ne orbiten e nje ylli qe nuk eshte Dielli quhet ekzoplanet, ose planet jashte sistemit solar. Dhe keto planete qe ne i quajme kalimtare kane karakteristiken se nese shikon yllin ne mes mund te shikosh se po vezullon. Arsyeja se pse po vezullon eshte sepse atje ka planete qe kalojne me rradhe gjate gjithe kohes dhe eshte nje orientim special ku planetet bllokojne driten nga ylli qe na lejon te shohim driten qe vezullon. Duke survejuar yjet gjate nates per kete vezullim levizez, jemi ne gjendje te gjejme planetet. Keshtu kemi qene ne gjendje te zbulojme mbi 5000 planete ne Rrugen e Qumeshtit, dhe sic e permenda atje jane shume me teper planete.
So when we look at the light from these stars, what we see, like I said, is not the planet itself, but you actually see a dimming of the light that we can record in time. So the light drops as the planet decreases in front of the star, and that's that blinking that you saw before. So not only do we detect the planets but we can look at this light in different wavelengths. So I mentioned looking at the Earth and Mars in ultraviolet light. If we look at transiting exoplanets with the Hubble Space Telescope, we find that in the ultraviolet, you see much bigger blinking, much less light from the star, when the planet is passing in front. And we think this is because you have an extended atmosphere of hydrogen all around the planet that's making it look puffier and thus blocking more of the light that you see.
Kur shikojme driten nga keto yje sic thashe, ajo qe shikojme, nuk eshte vete planeti, po aktualisht shikohet nje zbehje e drites qe e regjistrojme ne kohe. Drita bie sapo planetet dalin perballe yllit dhe kjo eshte vezullimi qe pate me pare. Jo vetem qe i zbulojme keto planete por mund ta shikojme kete drite ne gjatesi vale te ndryshme. Une permenda shikimin e Tokes dhe Marsit ne driten ultraviolet. Nese e shikojme nje eksoplanet me Teleskopin Hapesinor Hubble, zbulojme se ne rrezet ultraviolet, shikohen vezullime me te medha, shume me pak drite nga ylli, kur planeti i kalon perballe. Ne mendojme se kjo ndodh se ka nje atmosfere te mbushur me hidrogjen perreth planetit qe e ben te duket me te fryre e bllokohet me shume drite qe ne shikojme.
So using this technique, we've actually been able to discover a few transiting exoplanets that are undergoing atmospheric escape. And these planets can be called hot Jupiters, for some of the ones we've found. And that's because they're gas planets like Jupiter, but they're so close to their star, about a hundred times closer than Jupiter. And because there's all this lightweight gas that's ready to escape, and all this heating from the star, you have completely catastrophic rates of atmospheric escape. So unlike our 400 pounds per minute of hydrogen being lost on Earth, for these planets, you're losing 1.3 billion pounds of hydrogen every minute.
Nga perdorimi i kesaj teknike kemi qene ne gjendje te zbulojme disa eksoplanete kalimtare qe po i nenshtrohen hollimit atmosferik. Keto planete mund te quhen Jupitere te nxehte, per disa nga ato qe gjetem. Kjo, sepse ndodhen disa planete gazore si Jupiteri por ato jane kaq afer me yllin e tyre, rreth 100 here me afer se Jupiteri. Per shkak se atje ndodhet gjithe ky gaz i lehte qe eshte gati te largohet dhe gjithe ajo nxehtesi nga ylli, ka norma shume katastrofike te hollimit atmosferik. Ndryshe nga 200 kg per min te hidrogjenit qe largohen ne Toke, per keto planete, humbasin 590 milion kg hidrogjen cdo minute.
So you might think, well, does this make the planet cease to exist? And this is a question that people wondered when they looked at our solar system, because planets closer to the Sun are rocky, and planets further away are bigger and more gaseous. Could you have started with something like Jupiter that was actually close to the Sun, and get rid of all the gas in it? We now think that if you start with something like a hot Jupiter, you actually can't end up with Mercury or the Earth. But if you started with something smaller, it's possible that enough gas would have gotten away that it would have significantly impacted it and left you with something very different than what you started with.
Pra ju mund te mendoni, a ben kjo qe keto planete te ndalojne se ekzistuari? Kjo eshte nje pyetje qe i beri te mendonin njerezit kur pane ne sistemin tone diellor, sepse planetet sa me afer Diellit jane shkembor dhe planetet me larg jane me te medhenj dhe gazor. Mund ta filloje me dicka si Jupiteri qe ishte aktualisht afer Diellit, dhe te largosh gjithe gazin ne te? Tani ne mendojme se nese e fillon me dicka si Jupiteri i nxehte nuk mund te perfundosh me Merkurin apo me Token. Por nese do ta nisje me dicka me te vogel, eshte e mundur qe te largohej mjaftueshem gaz qe do te ndkonte ndjeshem dhe do te t'ju linte me dicka shume te ndryshme nga ajo qe e filluat.
So all of this sounds sort of general, and we might think about the solar system, but what does this have to do with us here on Earth? Well, in the far future, the Sun is going to get brighter. And as that happens, the heating that we find from the Sun is going to become very intense. In the same way that you see gas streaming off from a hot Jupiter, gas is going to stream off from the Earth. And so what we can look forward to, or at least prepare for, is the fact that in the far future, the Earth is going to look more like Mars. Our hydrogen, from water that is broken down, is going to escape into space more rapidly, and we're going to be left with this dry, reddish planet.
Kjo tingellon si dicka e zakonshme, dhe ne mund te mendojme rreth sistemit diellor, por cfare ka te beje kjo me ne ketu ne Toke? Ne te ardhmen e larget, Dielli do te behet me i shndritshem. Dhe ndersa kjo ndodh, nxehtesia qe vjen nga Dielli do te behet me e forte. Ne te njejten menyre qe shikon gazin te leshohet nga Jupiteri i nxehte, gazi do te leshohet nga Toka. Keshtu qe ajo qe mund te presim nga ose te pakten te pergatitemi eshte fakti se ne te ardhmen e larget, Toka do te duket me shume si Marsi. Hidrogjeni jone, nga uji qe eshe i zberthyer, ka per t'u leshuar neper hapesire me shpejt, dhe ne do te mbetemi me kete planet te thate dhe te kuqerremte.
So don't fear, it's not for a few billion years, so there's some time to prepare.
Mos u frikesoni, per disa miliarda vjet, Pra kemi kohe per tu pergatitur.
(Laughter)
(Te qeshura)
But I wanted you to be aware of what's going on, not just in the future, but atmospheric escape is happening as we speak. So there's a lot of amazing science that you hear about happening in space and planets that are far away, and we are studying these planets to learn about these worlds. But as we learn about Mars or exoplanets like hot Jupiters, we find things like atmospheric escape that tell us a lot more about our planet here on Earth.
Por une doja t'ju vija ne dijeni se cpo ndodh, jo vetem ne te ardhmen, por hollimi atmosferik po ndodh teksa ne flasim. Ka kaq shume shkence te mahnitshme qe degjojme se po ndodh ne hapesire dhe ne planete qe jane larg, dhe ne po i studiojme keto planete te mesojme me shume per keto bote. Por teksa mesojme rreth Marsit apo eksoplaneteve si Jupiteri i nxehte, ne gjejme gjera si hollimi i atmosferes qe na tregojne shume rreth planetit tone ketu ne Toke.
So consider that the next time you think that space is far away.
Keshtu qe mendoni kete, heren tjeter qe do te mendoni se hapesira eshte larg.
Thank you.
Faleminderit
(Applause)
(Duartrokitje)