Are We Alone in the Universe? with Lisa Kaltenegger – AMNH SciCafe


>>LISA KALTENEGGER:
I wanted to say that we live in this amazing time, that for the first time in human history
we actually have the means, the technological means—part of them developed here at the
Museum—to figure out whether we’re alone in the Universe. And I know there’s a lot of things that
are going wrong in our times and a lot of things are going through the news that you’re
not proud of, that I’m not proud of. But this is something that to me is astonishing. That our generation could be—we’re building
these telescopes right now and I show you what we found so far—that generation that
figures out if, when you look up in the sky, that there are other planets like ours with
signs of life out there. And I think that’s, to me, is one of the
most fascinating questions humankind has asked for thousands of years—are we alone? So what I want to do today is I would like
to change your view of our sky. And I’m a little bit cheeky. I’m saying 4.6 billion years of solitude. It could be more. We haven’t found life on other planets yet. But, as I said, we have the means and we are
building the telescopes to actually be able to spot signs of life on other words, planets
orbiting alien suns right now. And here, this is just my graphical expertise. This is the Earth in different colors, so
this is not images we get from anywhere. If you ever see an exoplanet image, an image
of a planet around another star, we have no idea what its surface looks like. We have no idea if there’s any plants. We have not much idea if there’s any colors,
okay? Artist’s impressions. So a lot of the things that I’ll show you
is our imagination leading us on to discover these worlds and glimpse into what they’re
made out of. So, are we alone in the Universe? When you have a look at this image—I found
that online, I don’t really like it, because it’s a human basically stretching out the
hand towards the sky. And the sky is really our new horizon. Because we discovered other continents. We discovered other worlds. But now our next horizon is actually the sky
out there. And, when you go out at night, and I know
it’s a little hard to do in New York City, but when you go out at night and in New York
somebody says you can spot two stars if you’re lucky. There are thousands of stars that you would
see in a nice, dark place like Ithaca, New York. Having said that, there’s not much else
happening, it’s very pretty. But we do see the sky. That’s, like, it’s a tradeoff right there. And so, when you go out in a darker place,
just go and do one, two, three, four, five. Science has told us we have found that one
out of five alien suns—those stars that you see up there are other suns—our sun
is a star. One out of five out of these alien suns that
you see in the night sky actually have a planet that could potentially be like ours. What that means is that it’s at the right
distance, where it’s not too hot and not too cold, so you could have liquid water on
the surface. And we could pick up signs of life if they
exist just by looking at the light from that planet. And that the planet is small enough that it’s
a rock like the Earth. And so if you had a huge cosmic bathtub, you
throw the Earth in, it would actually sink. You throw Saturn in, Saturn would actually
swim. Because the mean density of Saturn, a gas
giant, a very different kind of planet than the Earth, is less then water. While the mean density of the Earth is actually
more than water, so you’d sink. So our view of the night sky is our view to
other alien suns. And even so, we [can 4:39] spot them yet. It’s also our [view] to unseen other worlds,
where somebody could ask themselves a similar question: Are we alone in this universe? Let me just give you a bit of an overview
how we fit in this universe. This is an image of our galaxy. You Are Here—this is where we are. About halfway out from the center where there’s
a big black hole and the whole universe is about a hundred thousand light years across. What that means is that light needs a hundred
thousand years to get from this side to this side. It’s like when you’re driving a car, it’s
four-and-a-half hours to get to Ithaca. So, if you don’t have any cellphone reception,
when you get to Ithaca, the message that you have, the news that you have, is four-and-a-half
hours old, right? So, then all of these stars that you see out
in the night sky, what they also are, they’re our view back in time. Our closest star is four light-years away. So we see it today like it was four years
ago. And anybody who wants a nice birthday present,
let’s say somebody turns 20, Google a star 20 light years away, find it, bring your friend
and say, “I give you this star. The light that is arriving right now was sent
out when you were born.” Works every year. It’s a beautiful present. Really owns costs Internet access, that’s
mostly free. You do learn stuff in grad school. So, let me just go back—oh, one of the things
that I wanted to point out, all of these thousands of other worlds that we already have discovered—and
we’re above 3,000 now—are actually in this tiny region around our sun, in about
a thousand light years. So in our solar neighborhood. And, as I said before in our solar system,
we were used to these planets. The inner ones are rocky because it’s very
hot close to the sun. So gas and ice evaporated, only left rocky
material here. And the outer ones have much more gas and
ice, as I said, a cosmic bathtub, Jupiter or Saturn would swim. The Earth would sink. This is a size comparison. This is our Earth and this is Jupiter, the
gas giant. And, yes, our Earth fits into the storm that
is the red spot on Jupiter’s surface. But how have we found these thousands of planets
we’ve found so far? Well, actually, we don’t find the planets,
per se, but the star gives away that the planet exists. And so think about this way—you go through
Central Park and you see somebody walking like this, right? And this is the person who doesn’t want
to go the direction the dog wants to go, right? You don’t have to see the dog to know that
somebody’s actually pulling this person. And the further they go back, the bigger the
dog. In a way, it’s the same for stars. A planet pulls. The star leans back—they’re really going
around the center of mass, but it’s an analogy—the start leans back. And so, even though I don’t see the planet
here, I see that the star goes this direction when the planet is behind and … Now this
is not working. This direction when the planet’s here. So, by the wobble of the star, I can actually
tell that somebody’s tugging on it, something’s tugging on it, and it’s not a dog in this
case, it’s actually a planet. And that’s what you see here. And so sometimes the viewing geometry is right
so that, when this tugging occurs or this planet goes in front of the star, it actually
blocks part of the stellar surface, of the hot stellar surface that makes the star bright
from our view. And so the star for a little amount of time,
a couple of hours, appears a little bit darker than it used to be. And that tells you that something blocks its
surface light from your view and that something, if it’s small enough, is a planet. So it’s bright, bright, bright, then it’s
less bright because we don’t see all the hot surface, and then, when the planet goes
out of our point of view, we see the full brightness of the star again. And that’s what’s called the transit method. This is what Keppler used to find thousands
of planets out there in the sky. And, if you look very closely at this animation—and
this is an animation again—you see that when the planet’s in front of the star,
part of the light from the star gets filtered through the atmosphere of the planet allowing
us to read the chemical composition of the air off this other planet, just by looking
at the light that we get. And if you draw how many planets we’ve actually
found, it’s about 3,600 in current count. I think it’s 3,691, but who can keep up,
luckily? I usually tell my grad students, don’t worry,
there’s more than one planet for everyone. And then we have a lot of signals that we
still look at. But, basically, if this is the size of the
planet, 11 is the size of Jupiter and 1 is the size of the Earth, then this is how many
there are. So we have many, many more of the small planets
than of the big planets. What’s really exciting for me, because I
like the small planets, because I would like to find life in our lifetime. And I said most of the stars we see indirectly
by the movement of their stars. Most of these planets we actually don’t
see directly. But we already have a handful of these planets—and
there’s a brown dwarf just over there on this image—where the planet is far enough
away from the star, or we can block out the stellar light with a mask, so we can see this
dot of a planet. And of course to me, personally, the ones
that are most interesting are the ones that are in this temperate zone, where it’s not
too hot and not too cold for there to be liquid water on the surface. So, liquid water’s one of the key ingredients
for life and it also allows us to actually see the gases that life breathes in and out
in the air. If you have a huge layer of ice, and Enceladus
was the example we had before, this icy moon, you actually have to go, drill a hole and
see if there’s a fish. Could be a fish. Could be something else. Could be no life at all. This is why we have to go and look. And one of the things I wanted to point out
is that our sun, like every other star, is becoming brighter and bigger with time. And so in a couple of billion years—so,
don’t worry, we have a couple of billion years—we better be a spacefaring nation,
international nation, because this is how big our sun is going to get. This is how big it is now. This is how big it’s going to be. And this is the orbit, the distance of Mercury,
Venus and Erath. So, the good news is, in a couple of years,
billions of years, so lots of time, couple of billion years, you can touch the sun. The bad news is, it’s probably a smidgen
hot while you do that. But we have one, one object that has left
our solar system: Voyager I. Voyager I is the only human-made object, human-touched
object that ever left our own solar system. And before it did that, it actually had a
look back and looked at the Earth. And this is what it saw. This is the Earth. This tiny, pale blue dot that Carl Sagan wrote
an amazing, beautiful poem about. And this tiny dot still tells you a lot of
information. So you have this tiny dot and you really can’t
see continents or oceans, but if you split the light in its colors, the light that gets
to you gets filtered through the planet’s atmosphere to you, then you can check if there’s
some energy missing. Because light is energy. You put your hand out and you see that it
gets warm. So light, when it hits molecule in the air
all around us can actually hit them so they start to swing and rotate. And that light is unique. The one that’s missing to the molecule that
it hits. And therefore the light that does not get
to my telescope tells you what the composition, the chemical composition of the air on another
world is. And it looks a little bit like you had an
apple and you took bites out of it. This I show you can say which molecules in
the air of a world that are really, really far away. Of course, we also have planets that don’t
have life, like Venus, and they have their own light fingerprint. So we know how life light fingerprint looks
like—that’s oxygen with a reducing gas like methane—and how other planets that
don’t have life look like. And so the spectral fingerprint of life for
our own planet is ozone with methane and water. And that’s what we’re trying to find on
other worlds. And the last tiny point that I wanted to make—life
of course doesn’t have be like you and me. Life can be very, very different. And then the planet would also appear very
different. If you think about a huge algae bloom, for
example, that could cover the whole world. It could be red or it could be yellow, it
could be any color you really want. And life could be very cute or this is a really
interesting extremophile. It’s called a water bear and it basically
survives anything. You can radiate it. You can even put it into space, they took
it space, opened the door, put it out without any protection. Three days later, they put it back in, put
a little bit of water on it and it was like dadadadada, it was fine. So this is probably really where astronauts
go in the future, something like this. Dehydrate them, get a little bit of water
on them. I actually gave a talk to about a hundred
astronauts. They did not like that joke at all. You find these extreme forms of life here
on our planet. For example, in Yellowstone, all these different
colors are different forms of life. And so we’re looking at that and we’re
making a color catalogue of life, of life that’s just not the flower you think of
or the tree, but different forms of life that can live in very, very different conditions. And this is just a sub-sample of the color
catalogue of life we assembled. And one of them is a coral that biofluorescences. So, why I want to bring that up is that, in
addition to these other Earths maybe not being a pale blue dot, but red blue dots and green
blue dots and any other color you can think of, we could actually also have really weird
lifes. And some of the last planets that were discovered
are orbiting small, red suns. One of them, our closest star. Even our closest neighboring star, our closest
star is the sun, 8 light minutes from us—the one after is four light years away from us,
Proxima Centauri. So if you shrink our solar system to the size
of a cookie and I want everybody to think about cookies and astronomy together now whenever
you have a cookie, then the next star in the same scheme is two football fields away. And I was told not to use “soccer” here. Even so, the ladies’ team is doing great. But the question is, this star, this red sun
is very different because it has flares, so it hits its planet with huge amounts of UVs. But actually the coral I just showed you before,
if you hit it with huge amounts of UV, what it does, it actually biofluorescences. So maybe—and this is a big “maybe”—on
another world, this is work that one of my postdocs did in my lab, on another world such
a huge flare of UV radiation that might be really bad for life could actually lead to
a sign of life for us to be able to detect it in the biofluorescent flare. And of course to think about this, there’s
this other system we discovered small star, seven Earth-sized planets. The other planets in your night sky, if you
were standing on that planet would be as big as the full moon. And then just imagine you’d see two of them
on each side of you and they might actually flare in this beautiful biofluorescent colors. Does it exist? I don’t know. But it’s definitely something that we should
look for with the next telescopes. And so our reach towards the star is one that
we’re just starting. And I sometimes like to think about this,
like we’re making a travel list for the coolest destinations around our solar system
and beyond. We’re taking together what we have and we’re
making like a Lonely Planet’s top ten list for travel bucket lists. We don’t have the ships yet to get there,
but one of the things we do have is the first information of our travel destination. And in 2019, we’ll start the follow-up of
Hubble, it’s a 6.5 meter telescope, so it’s about 4 times me in size, that will be in
space. And for the first will be capable to collecting
enough light to actually find signs of life on other worlds close by, if such life exists. And so I think we live in an incredible, exciting
time. And we are the generation that can actually
transition from “are we alone to the Universe?” to “Ooh, we figured it out.”

30 Replies to “Are We Alone in the Universe? with Lisa Kaltenegger – AMNH SciCafe”

  1. What’s not to be proud of? Inserting blatantly ignorant political opinion into what should be politically agnostic science?

  2. What makes me confused is Why we always want to colonise mars? Why always mars of every planet? It seems like the conditions of this planet is mot particular suit for us? All the documentaries and Hollywood movies always focusing on mars? There is even a program in NASA to make it to mars and colonise?

  3. Fermi-paradox solution?

    Evolution of intelligence may depend on small social groups, as we observe in human evolution, and in Earth's most intelligent birds, wolves, dolphins and apes. Groups of a dozen to a couple of hundred individuals, seem to be a prerequisite for developing any kind of higher intelligence.

    If that is a general principle, then no Kardashev 2 or 3 civilization can ever exist.

    In fact, large coherent civilizations may only be a short-lived artefact, of an intelligent species lack of technology to roam free. And as soon as such technology is realized, civilization will disintegrate naturally.

    I mean, if you owned a UFO, that provide everything you need for free, and lets you travel anywhere in the universe … Would you stay in your apartment? … Would you keep your job? … Probably not.

    Rather than living and corporating with strangers, in a competitive and stressful environment, most people would prefer to travel with friends and family. 'Tuning out' is a strong inclination, due to our evolutionary roots. An inclination currently only suppressed by our need for goods and convenience.

    If indeed intelligence only evolves via small social groups, then such inclination must be true for any aliens as well. And, the Fermi-paradox actually suggest that this is a universal principle, just by demonstrating a lack of large detectable civilizations in our universe.

    Technologically mature civilizations may simply disintegrate, and small groups of individuals spread so thinly across the universe, that detection becomes impossible.

    This could be our faith as well.

  4. of course we are not alone … you would have to be self centered to think otherwise. Life is probably not anything like earth though… so what we are looking for is probably wrong. Further, an advanced civilization would be smart to use neutrinos to communicate since they can go through all types of matter unimpeded. So, we should look for neutrino signals not em signals. em signals are too noisy with many sources.

  5. You need modern technology to tell you we aren't alone?! If the universe is infinite its silly to think we are the only ones here. We havent found life? Can you reach into the infinite universe and check? No? Stop treating our galaxy like its special and rare

  6. We are not alone and never have been. ETs have been visiting Earth forever. Governments know all about it but have suppressed it to maintain a monopoly of power. Corrupt people in power will do anything to maintain that structure of control – and they have. The existence of alien life undermines EVERYTHING about our control and governmental structure. It undermines the economic system, mind control through religions, the energy system we pay so much for and everything else.

    The governments know all about the free energy that's available, Tesla/ Zero Point energy etc but it would collapse the economy and the control they depend on to exist. We could all be living in a FREE WORLD – RIGHT NOW, if enough people wake up to this. We are all responsible for what happens..do not rely on the same corrupt governments who have lied to keep this secret and profit-based media to tell you the truth.. plenty of free information is available about this. Check out The Disclosure Project on youtube where many high level people have testified to this cover up.

  7. These "nobody out there" videos are annoying to me. My wife and I were out stargazing at the NC beach one night and a brightly glowing perfect triangle-bright red-flew smoothly and silently over our heads and right down the beach. This was 1989. Yes it could have been faked by someone who built a perfectly triangular airplane out of translucent material and internally lit it with many red lights until it glowed evenly like a charcoal briquette and it had a silent engine-sure. If you can't tell, I'm being sarcastic. Put yourself in my shoes for a second. I concluded we were observing an alien vehicle. I've since heard the testimony of retired military officers who observed what could only have been alien spacecraft hovering over and then shutting down the nuclear missiles on their bases (and FOIA-requested AirForce documents and other military witnesses back them up) or who chased UFO's with fighter jets like https://www.cnn.com/videos/us/2017/12/20/david-fravor-intv-us-navy-pilot-ufo-encounter-sot-ebof.cnn . Videos like the one this criticizes completely ignore the UFO phenomena either innocently or intentionally. More denial is just annoying at this point. Government denial is fading and disclosure is being unfolded in bits and drabs but it is happening finally. See the videos of gun camera footage by military jets on https://www.youtube.com/watch?v=tf1uLwUTDA0 and the pilot again
    https://www.youtube.com/watch?v=jCaruUtiPHo&t=51s

  8. I'm pretty sure we are not asking the right question, whenever we ask whether there is life on other planets, let alone so-called intelligent living things (it may be a good question, although not an original one, I think it merely reflects our lack of knowledge and narrow-mindedness, and the fact that we are unable to imagine other highly complex entities outside the realm of living organisms (that includes all human-made things, too, of course) with which we are more or less familiar with). Sure, it is highly likely that there are similar life forms on other planets that are similar to Earth, but there may be some other extraterrestrial things on other planets which we wouldn't even call LIFE because these things would be very alien to us and radically different from everything else that we currently know about – strange manifestations of matter that we can't even imagine yet with our present knowledge and understanding of matter and the universe. Just think about it, simply put, living organisms on this planet are really just highly complex manifestations of matter. Who knows what else there is outside this Earth…?

  9. Are WE alone in the universe? A universe that encompasses so many things beyond our knowledge we can't count them all. There are black holes, countless stars and planets. Would this universe really therefore have Donald Trump be the most powerful man in it? Doubtful.

  10. Adam didn't become a living soul until God breathed life into Him. And if God withdrew His Spirit man would wither and die.
    The Lord, who stretches out the heavens, who lays the foundation of the earth, and who forms the human spirit within a person…
    I have not met anyone who hasn't heard of Gods message of salvation given through Jesus. As in these last days God has spoken to us by His Son.
    Gods salvation is forever – the present creation along with our bodies has been subjected to decay by the creator
    Lift up your eyes to the heavens,

    and look at the earth beneath;
    for the heavens vanish like smoke,

    the earth will wear out like a garment,

    and they who dwell in it will die in like manner;

    but my salvation will be forever,

    and my righteousness will never be dismayed.
    For those who believe in the Son and go to Him for life they will be raised with new bodies not of the dust of the earth.
    And God will provide
    "See, I will create new heavens and a new earth. The former things will not be remembered, nor will they come to mind.

  11. Yet another one that poses the question relative to the “universe” instead of the “galaxy.” Believe whatever you like about the universe, which is truly vast, but we will never detect signs of intelligent life in galaxies other than our own.

  12. There is no other life. The chances of life happening as we did is 10 to the 123rd power. There are 10 to the 53rd power stars in the Universe.

  13. Yes we are alone. If 1 out of every 5 stars had an earth like planet and if 1 in a million of those had intelligent life, then there would be technologically advance species everywhere we look. We would have found them by now and they would have found us by now.

  14. Whenever NASA decide to launch the James Webb Telescope, It will search exoplanets for biosignatures. This may lead to the discovery of life.

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