"Mysteries of Deep Space"
Program 3: "The Search for Alien Worlds"
This could be the Rosetta Stone...
A distant star offers a startling revelation.
This could be a for-real solar system.
Thatís frightening, is what it is.
Now that weíre realizing there are planets out there, that there may be life out there, I think the galaxy is beginning to seem like something of a romantic place again.
From Mars and other worlds within our solar system...
To the far reaches of the Milky Way...
We've got to come to terms with life being so much bigger than anything that we have recognized just by having one set of planets.
The question resounds across deep space: Are we alone?
In 1994, astronomers detected a planet around another star. But itís a world that was stillborn -- formed of material thrown into space when its sun blew up.
They found a second that is no planet at all. It turned out to be a dim star called a brown dwarf that's simply caught in the orbit of a much larger star.
And yet, there is reason to believe our galaxy teems with planets. Fifteen hundred light years from earth, the Orion Nebula is one of its most active regions of starbirth -- And a hotbed of new solar systems.
Using the Hubble Space Telescope, astronomers are combing this region for moments that mark the early lives of stars -- and even planets.
Something remarkable has appeared around fully half the young stars sighted: vast platters of dust and gas, ten times larger than our own solar system.
In time, gravity will concentrate this material... Drawing it together into asteroids and comets -- but also planets and moons.
There are a hundred billion stars in our galaxy. A recent study claims that there may be half a trillion planets. Where, astronomers ask, are there worlds like our own?
Weíve seen ourselves as alone in this enormous universe in which, ah, the distances are so, so great that they boggle our minds. And yet if we could only find life in other places, we would realize that we belong with them, that all together we make up something that the universe was calling forth because it needed it.
If we were to discover life elsewhere in the universe, so long as it can be shown to be independent of life on Earth, I think that will be the greatest scientific discovery of all time. Now the reason I make this statement is because, according to conventional biology, life is -- is a freak, a fluke, a statistically extremely improbable accident that occurred just here on Earth.
For millennia, we have locked our gaze on the heavens, awaiting some glimmer of other worlds. Tonight, our suspense is finally rewarded.
At the Lick Observatory near San Jose, California, a momentous discovery is at hand.
These four are locked in.
These four are rolling. I will get these two going next. I think these are the next two highest.
I mean I think this... If we had to give a talk tomorrow on giant planets, those four stars would be the ones we would be talking about.
Paul Butler and Geoff Marcy are planet hunters. They are astronomers who study the nuances of stellar motion for hints of planets... Using a technique they pioneered.
For eight hard years theyíve been laboring in obscurity. Now theyíve been beaten to the punch. Rivals just scored the first true planet ever discovered beyond our solar system.
The Swiss team of Michel Mayor and Didier Queloz have announced the detection of a planet circling the star 51 Pegasi. The news made headlines around the world.
Marcy and Butler confirmed the Swiss finding.
It was not the kind of planet anyone expected to find: a giant, even larger than Jupiter, yet so close to its star that it speeds around it every four days. Its atmosphere is heated to about two thousand degrees Fehrenheit.
Its parent star, 51 Pegasi, is as bright as our own sun. Planet hunters cannot see through its glare, but they can tell thereís a planet by charting the minute effects of its gravity.
Okay, Wayne, roll ëem, 51 Peg.
So 51 Peg would be expected to have a radius of about 30% larger than our own Jupiter...
...itís gonna have the same radius.
Starting the exposure...
Well, you can think of it this way. Our sun sits like a giant bowling ball and the biggest planet in our solar system, Jupiter, is one/one thousandth of the mass of our sun. So when Jupiter goes around, it barely moves the sun around. So our sun is an -- an almost immovable rock in the face of Jupiter, but the sun does move a little bit and hereís how fast. The sun moves about 12 meters per second, which is about the same speed as the fastest Olympic sprinters. So our sun is in effect sprinting around in a little circle due to the pull of Jupiter.
We just got a great exposure on 51 Peg. Forty-six hundred counts? Thatís excellent...
A star's wobble, even a slight one, is the calling card of a planet. Marcy and Butlerís readings are so precise, they can study stars one hundred light years away, and detect a wobble down to three meters per second -- the equivalent of human jogging speed.
Marcy and Butler are looking for a wobble that displays a more complex pattern -- The sign of an actual solar system. The prospect is that much closer -- as eight years of data come into sharp focus.
This is... This is huge.
Thatís frightening, is what it is.
Itís frightening, itís huge. There is something really wacky going on in this system. Itís happening wacky literally on periods of days or weeks. But then over many years youíve got this wild trend going on. So this could be the first authentic real live solar system thatís detected. We wonít really know until we get another year or two of observations.
This star, 55 Cancri, is one of the hundred and twenty candidates in our corner of the galaxy that Marcy and Butler are surveying.
This could be two or even three planets.
This is beyond our wildest expectations from when we started this eight years ago.
We're going to have a few dozen new planets discovered within the next year. So we've gone almost all of humanity's existence discovering the nine planets in our solar system and suddenly our inventory of planets is going to double or triple within the next -- literally the next year.
I want to see two, three more points, then Iíll believe it.
As our discoveries mount, so do our hopes. Each new one brings us closer to solving one of the deepest mysteries in science...
The question is are there other planetary systems which have a planet somewhere in that system which has the characteristics, ah, which make life possible, liquid water primarily.
People have wondered since antiquity whether life on Earth is an accident, whether -- whether, ah, things happened in other places the way they happened here. I think we now have a scientific basis to conclude that it's quite likely that life has happened elsewhere. In fact, I would say an absolute certainty. So I think youíd have to be made out of stone not to want to know the answer to that question.
It would certainly surprise me if we were unique. Having said that we were interesting and complicated, I still at the same time think that we arose according to perfectly understandable, if complicated, steps. I donít think there was any magic or divine intervention. So it seems reasonable to me to think that there are a lot of hospitable places where people like us could have evolved.
Technology is advancing our search for other worlds. Through history, weíve also employed a tool just as powerful: hope.
The Seventeenth Century astronomer Johannes Kepler imagined that intelligent creatures had constructed dwellings on the sides of moon craters.
In 1835, a newspaper announced that a noted astronomer had glimpsed astonishing details of moon creatures. They were the Selenites, a civilization of lunar man-bats.
Plans were hatched to make contact. Missionaries stood ready, while abolitionists vowed to rid the moon of any incidents of slavery. If anything, the great "Moon Hoax" only fueled our appetite for aliens.
To early civilizations the Red Planet evoked blood, fire and war. The Romans named it for their god of battle... Mars.
At the end of the 19th century, the Italian astronomer, Giovanni Schiaparelli, noted markings running down the planet. On closer examination, he saw lattices of double lines. He began to name them, and connect them in a vast global network.
He speculated that they carried melting snow from the poles to the dry interior.
For one astronomer, Percival Lowell, the lure of these features was irresistible. He commissioned a new telescope to study the martian landscape for himself.
Lowell saw them as canals, and found twice as many as Schiaparelli. He came to a dramatic conclusion. They were traces of a sophisticated society intent on shaping its environment on the grandest of scales.
Lowell looked at Mars and he thought he saw the future of Earth. He looked at this planet, the red planet Mars, and thought here was a dying civilization desperate to rescue itself from what we would today call an ecological crisis. He thought the same thing would happen to Earth and eventually Earth would dry up as well and become a planet where we had to build a -- some kind of network of canals to save ourselves from -- from drought and famine. So he thought that Mars was a vision of our own future.
With an impassioned series of best selling books, Lowell pitched his vision of Mars to his eager public. But was it true?
No, said his peers. But Lowell would not be deterred. He sent the astronomer David Todd to South America to gather more evidence.
Todd took pictures by the thousands, and analyzed them in detail. His conclusion: canals aplenty.
Oh, I think at the end of the last century, it was still possible to be a serious astronomer and believe that there might be advanced life there. Although astronomy was in a fairly advanced state at the turn of the century, biology certainly wasn't. The -- the nature of life was very ill understood, the molecular basis for life was still at least 50 years away. And so, nobody really had a clue about how life originated or would evolve on other planets.
While the debate raged, Mars gripped the popular imagination.
Who were these martians who had mastered the elements through engineering? They must have evolved even beyond the human. They owed their large heads, barrel chests and long snouts to reduced gravity and a thin atmosphere.
Mars was alluring... And it sold soap.
Schemes for making contact abounded. Giant mirrors would flash a greeting. Light beams. Call them up. Or use mental telepathy.
Perhaps, said one French astronomer, an ancient race of martians had been signalling us since the age of the dinosaur. They simply got tired of trying.
Today, astronomers routinely monitor radio energy from space. In the 1920s, however, the notion was nothing short of radical.
One maverick believed he could receive messages from Mars:
it was David Todd.
He was a visionary in one sense. He saw the coming age of interplanetary communication when humans would routinely communicate with other worlds, not with martians, but with space probes that humans have sent out to Mars and to other planets. Ah, Todd, ah, made what was probably the first feasible proposal for interplanetary communication, which was launching a balloon with him aboard and a radio receiver that could, he hoped, detect signals from martians who might be trying to contact Earth.
With great fanfare, Todd announced his fateful launch. He would listen for martian signals from high in the atmosphere. The project never got off the ground.
In 1924, Todd convinced the U.S. Armed Forces to suspend communications for an unprecedented three-day period. As Mars approached its closest orbit to earth, all ears were tuned in. Speculation abounded. But there was only silence.
Then, the aliens found us.
Whatís that? Some sort of a war tank? Theyíre not human!
What did they want from us and our fertile planet? In the years that followed, motion pictures enacted the moment of contact when aliens would make their case.
They came to take control of our world...
Youíll find that conquering the Earth isnít so simple.
Big eyed alien
This is our planet, Astron Delta.
They sought haven from a hostile universe...
Big eyed alien
During our twenty-third time rotation, our sun began to die. Our eyes developed to this state to combat the ever growing darkness. We were forced to migrate.
They yearned for our family values...
Welcome Santa Claus, we hope youíll make the children on Mars very happy.
Iíll try dear lady.
They would stop at nothing to recover the one resource they had lost in a cataclysmic war... Men!
Who are you?
Devil Girl from Mars
My name is Naya. I will select some of your strongest men to return with me to Mars.
And if they donít want to go with you?
Devil Girl from Mars
There is no "if."
Scientists adopted a somewhat more sober view. In the 1950s, they began to envision the day when astronauts would actually venture to Mars to explore it.
But much of Lowellís vision of the planet had endured. Mars was depicted as harsh, barren, yet Earth-like, with running water and sparse vegetation. This myth was about to be dashed.
In 1964, the Mariner Four mission sent back a startling set of images of the martian surface. Lowellís canals were not the product of Nature or martians -- But of his fertile imagination.
I will never forget as long as I live seeing the front page newspaper with these pictures from the Mariner IV Space Probe. And I realized at age twelve that there were no martians, there were no martian canals, all those marvelous visions of life on the red planet were all wrong. And, for me, it was much worse than ceasing to believe in Santa Claus or, for that matter, ceasing to believe in God, because it took so much romance out of the solar system. And after that the solar system began to seem like a more alien, inhuman place.
Mariner showed that Mars was barren, but perhaps not lifeless. In the 1970s, the Viking mission landed two probes on the planetís surface to look for chemical traces of life. The venture gave voice to a new generation of optimists.
JPL Control Room announcer
Yes, we have a touch down time of 12 hours....
The probes spent months scooping and analyzingmartian dirt. In the end, they failed to find any evidence of life.
At Earthís doorstep, it seems, creation has placed a lifeless desert.
But today, scientists are looking at Mars anew.
If in the distant past life did develop on Marsí surface, it was killed off by an increasingly severe environment. Once the planet was warm and wet like earth. Then its atmosphere thinned, and it plunged into a deep ice age.
The surface of Mars has remained frozen in time. For billions of years, the planetís thick crust has prevented the welling up of molten rock from its core. What Mars lacks is the volcanic activity that has long replenished our atmosphere, and circulated water from below.
By three-and-a-half to four billion years ago, Mars still had water. So it's not at all unreasonable that early Mars, as well as early Earth, had abundant microbial life. However, then Mars and Earth diverge very substantially geologically, for reasons that we donít understand fully at this time. Mars now is left with only a very small atmosphere, an atmosphere which is only a few-thousandths the pressure of our own atmosphere. Mars dried up a billion or a billion-and-a-half years after its formation. Earth, on the other hand, retained its water.
The search formartian life isnít over. In preparation for future expeditions to Mars, scientists are studying another harsh corner of the solar system.
Welcome to Mono Lake, California. On the eastern side of the Sierra Nevada Mountains, this is an otherworldly realm.
Jack and Maria Farmer are paleontologists, of a sort. Itís not dinosaur bones theyíre after. They work for NASA, and they are setting out to discover an extraterrestrial empire -- of microbes -- the kind that may have thrived on Mars in its early days.
Most of this area where we worked last year, you know the waterís come up and covered the....the spot, so weíll have to try to relocate everything...
My feeling is that life could well be just a by-product of solar system evolution and wherever you have the right kinds of environments, namely liquid water and the right mix or organic compounds, that life will originate and get going.
Mono Lake is stocked with a kind of primordial soup. Encased in its rock formations are primitive organisms. Billions of years ago, they were among the first life forms on our planet.
Remarkably, this basin has much in common withmartian craters formed by large meteors.
This spot on Mars called Gusev Crater we think, ah, is a place where there was once a lake, and the commonality here is that all of the streams that flow into the Mono basin end here. There -- there are no out-flowing streams. It's a terminal lake basin. Water comes in, but it only leaves by evaporation. If you look at Gusev Crater on the surface of Mars, you see the same sort of thing, where you have a big channel flowing in, but nothing flowing out. So it was also a terminal lake basin.
Along these banks are towering rock formations known as "tufa." They are rich in carbonates, a mineral that forms when salt and fresh water meet. These microbial spawning grounds make Mono Lake a living laboratory for primitive life forms.
Okay Maria, this tufaís very porous. It has large cavernous openings...
And these basically are spring deposits. They form where water flows up into the lake floor. And these structures, as they form, entrap micro-organisms and preserve them as fossils.
At the microscopic level, the remains of tiny microbes are encased within layers of minerals.
Itís fossils like these that NASA hopes to find on Mars. Already, the planet may have given us a sneak preview.
The scientists will lay out for you how an ancient rock found itís way from Mars and got to earth. After billions of years, to have this rock to tell the people of America and the world an amazing story.
According to scientists, three billion years ago, a meteor struck Mars and sent a rain of debris into space. One rock wandered through our solar system till earthís gravity finally drew it in.
A group of NASA scientists concluded that the rock bears markings that may indicate the presence of ancient microbes.
But Martians, be they men or microbes, have defied our speculations before, so caution reigns.
I quote Carl Sagan: "extraordinary claims require extraordinary evidence." And I happen to regard the claim of life on Mars present or past as an extraordinary claim, and I think it is right of us to require extraordinary evidence in support of that claim.
Okay, now minus five, four, three, main engine start....one, zero, and LIFT OFF of the Delta Rocket with Mars Pathfinder.
In pursuit of that evidence, we are now venturing back to Mars.
In December 1996, a spacecraft called Pathfinder began a seven month journey to renew the search for ancientmartian life.
July 4th, 1997: Pathfinder approaches Mars, moving around to its night side. Its goal: to begin a planet-wide search for a staging ground, suitable for collecting specimens.
Its arrival is cushioned by technology borrowed from the modern highway... Airbags.
When the lander finally comes to rest, a rover, no bigger than a microwave oven, emerges. For five months, the sun powers its work, as it tests rocks for an array of minerals. And the rocks will test it.
Meanwhile a second probe arrives and orbits the planet. Using remote sensors, the Mars Global Surveyor maps the distribution of minerals across its surface.
Finally, with its destination chosen, another rover will follow up in the first decade of the millenium. It will collect mineral samples and return them to earth.
A big part of the Farmersí work is to help calibrate the sensors of these probes. They are taking readings along the shores of Mono Lake.
The plan is to do a series of points down to the shoreline. Why donít we start with this loose ash where thereís no plant cover.
Sample description: Loosely consolidated ash and...?
During this early period in Marsí history there was a constant rain of organic molecules onto the surface being delivered by comets, by interplanetary dust particles, and so on, and at the same time that was happening we also know we had liquid water available at the surface. Life could have originated on Mars because we had all the basic ingredients: liquid water, all the organic chemicals, and enough time.
In our seach formartian life, we may be only scratching the surface. Deep underground living microbes may still flourish there.
Where do we go to find extantmartian life, if it exists? I think that the most logical place to go is sites associated with volcanism.
And if you have a hot spot, water in the crust, that water will at some point be melted. And thatís the sort of setting we have to be able to seek if we're to see life on Mars. I donít believe that thereís any standing water on Mars. We must be prepared to drill for it or if we find open volcanism on Mars -- open volcanism as manifested by fumerols, steam vents, for example. Thatís also where the very earliest life on Earth was.
If it turned out that the biochemistry ofmartian life was fundamentally different from that of Earth life, it would show that life can emerge and evolve in more than one place, and it would, I think, strike at the -- at the very heart of the basic paradigm on which our understanding of -- of biology is based, which is that it's a result of just a sequence of incredibly improbable accidents.
To find other life in our solar system, we may have to prospect for it, and Mars may not be the only place to dig. The conditions of life may also exist on one of Jupiterís moons.
Beneath Europaís crust, scientists believe, is an ocean of volcanically heated mud -- just the kind of environment that can spawn primitive microbes.
The turbulence churning below is written across a veneer of ice. Europaís surface is rent with fractures. The spacecraft Galileo recently sent back images of a zone, bulging with spill-over from the moon's roiling interior.
If life exists here, then who can doubt it also has emerged in the universe beyond?
Today we are searching for alien life with new technology and new energy, but with the same optimism that once bouyed the hopes of Lowell and Todd.
At the vanguard of this quest is a venture that believes firmly that advanced civilizations are even now trying to contact us -- With radio signals. We have only to put our ears to the cosmic rail and listen.
It's called SETI, the Search for Extraterrestrial Intelligence.
This is not just another piece of science, as interesting as that may be. This really hits at the gut level. Are we alone? Are there other creatures? What do they look like? How do they act? How do they deal with their environment? Are they going to come visit? What can they tell us?
Paul Horowitz's search began in 1985 at the Harvard Radio Telescope. Backing the venture was Steven Spielberg, along with a host of extraterrestrial enthusiasts.
If thereís a plausible argument that there isnít anybody out there, bearing in mind that we can be wrong, we ought to keep looking. Because the question is of the most supreme importance. It calibrates our place in the universe. It tells us who we are. And so it is worthwhile trying to find other civilizations, I would say, no matter what.
In those days, Horowitz monitored a million radio channels across the entire sky. Today, he's upgraded to a billion channels.
Earth is routinely barraged by a shower of radio waves, generated by myriad natural sources throughout the cosmos. What SETI is listening for is a distinctive, repeated signal that could only be produced deliberately.
During the quarter century that SETI has been tuning in, there have been a handful of tantalizing receptions -- but little more to bolster the vigil. Still, its supporters are willing to wait decades for a sure sign of intelligent life.
Those of us who are -- who are devoting our scientific lives, or a significant fraction of it, to searching for signals from creatures that we have no evidence even exist clearly are driven by something. And I think in my case it's simply the realization that we are literally the first generation on Earth that could realistically communicate over galactic distances. We are the first. Fifty years ago we didn't have a radio telescopes that were required. There's all the reason to believe that other life exists in the galaxy and, in fact, other advanced life may well be signalling to us at this very moment. So how can you not search for signals in space?
SETI is a gamble, but it's an intelligent gamble because you can take modern science and, with it, make certain reasonable predictions of what the rest of the universe is like. We can reasonably forecast that other worlds out there in space may have life on them and that that life may have evolved over millions or billions of years into creatures that are intelligent and that may be interested in communicating with us.
It's not a question of having enough power. We can send radio communications and receive them a long way. We just have to decide how to look and this discovery of planets that's going on now is opening up this whole field for further study. If we can discover other solar systems, then we'll know where to point.
Announcer, KTVU News
Two San Francisco State University astronomers say they have discovered yet another planet outside our solar system, circling a star some 40 lightyears from earth...
The word is out.
We live in a solar system ourselves, and we know that life...
(Translates Geoffís words)
In a string of announcements, Geoff Marcy and Paul Butler have unveiled the discovery of three new worlds around nearby stars.
The names Butler and Marcy are in the news.
These latter day Columbuses are hot on the trail of new planets.
All they need now is a press agent.
Hello, you have reached the office of Geoff Marcy and Paul Butler. Please leave a message at the tone.
Phone Voice 1
Hi. This is a message either for Geoff or Paul. This is Mike Shapiro with the magazine "Web Review," weíre an internet publication, and I'd like to talk with you, hopefully within the next couple of hours, about your discovery, and your publication of it on the web.
Phone Voice 2
Hi, my name is Leslie Koren, K-o-r-e-n, and I'm calling from KPIX Radio in San Francisco. I was hoping to set up an interview with you tomorrow morning about your new planet....my number is 415....
This radio thing ain't gonna' happen.
Weíre swamped. I got three or four calls from TV stations this morning. I told one of them at 1:00 P.M. Iíll be free. The problem is we have an enormous amount of work to get done right now. We have proposals to write. We have planets just waiting on our hard discs and we just need enough time to analyze, and it's sort of a Catch-22. The media is taking up our time which is preventing us from doing what it is the media wants to talk to us about. Itís kind of curious.
The public is clammoring for news of other worlds -- With its expectations perhaps shaped by those planets we know.
Nine companions move around our sun, in nearly circular orbits. Inner planets, such as Venus are subject to the seering heat of the sun.
Jupiter is one of four gas giants that skirt the fringes of the solar system. They are no place for life...
But the third planet out boasts a remarkable combination of attributes. It's just the right size -- set in the right orbit, at the right distance from the sun. It passes its time squarely in what scientists call the life zone.
But are there other solar systems like ours? Marcy and Butler offer some answers in the planets they've found.
The one around 47 Ursa Majoris, is a planet of about two Jupiter masses. If you put that planet in our solar system at the right distance, you'd say, "Gee, that looks like a normal planet." On the other hand, weíre seeing other planets around these other stars that really look very, very different. Some of the planets are in too close. We have two planets that are extraordinary close to their star and we have two planets that are in orbits that are noncircular, very eccentric, elongated orbits. And we don't see planets like that in our solar system.
This is one of the most important revelations of Marcy and Butler's discoveries: most planets discovered so far, it seems, do not inhabit solar systems like ours.
55 Cancri has a planet the size of Jupiter, but it's so close to its sun, it races around it every fifteen days.
A planet orbiting 70 Virginis is six times heavier than Jupiter. Its path takes it drastically close to its star, then swings it wide.
Scientists are now using supercomputers to understand what forces conspired to shape their orbits.
Theyíve designed a solar system with two large planets, close enough to fall under each otherís gravitational spell.
Each time the pair passes, their mutual gravity tugs them gradually out of orbit. Inevitably, they cross paths.
One planet is flung to the outer reaches of the solar system. The other hurtles toward the sun, where it is captured. This is also the fate that would await a smaller planet, the size of Earth -- and with it would go the prospect of life.
What is exciting with regard to theory is that we are finding planets that completely defy our prior conceptions as to how planets sort of formed. And that's the glory of science. We can reject in part some of the notions that were too narrow about how planets formed and we can now embrace a much wider range of processes that lead to planets.
Hostile solar systems may well be the rule in our galaxy. The question will fall to the next generation of planet hunters. Theyíll use an arsenal of new technology.
This mirror, nearing completion at the University of Arizona, is eight meters across. One of the largest in the world, it will be outfitted with advanced optics that will further the search for smaller planets.
Itís the brainchild of Roger Angel.
The bigger the mirror, the sharper the image you can make if you correct for the atmosphere. The curiosity about whatís out there, where we live, are there other planets like ours,I think these are universal questions. The richness of the universe goes beyond our imagination. And it's telescopes like this that let us go out and find things that perhaps we could never have imagined.
Astronomers are planning to begin searching from a new vantage point: space. In an earthly realm devised to simulate conditions in zero gravity, a crew rehearses for a space-age overhaul.
Two astronauts are prepping for a return mission to the Hubble Space Telescope. In a massive tank at the Marshall Space Flight Center in Alabama, they practice installing a new set of instruments.
As in space, a team of engineers guides them through the delicate procedures. Divers and camera operators document their every move.
Good copy, Pete, good copy.
The instrument package they are installing includes a special camera designed to block out the glare of a star and reveal any planets in its midst.
Well itíll be a lot easier in space that it is in the water. Thereís so much drag in the water and all the tools on the end of the tether fall to the bottom of the, fall down, instead of being in your work envelope. We keep pulling them back up.
I think Hubble has gained quite an appreciation by the general public in just the last few years because of all the spectacular pictures. Itís a great mission. You know, itís one of those missions that only come along so often, and most of the astronauts want to be on flights like this.
Our ultimate view of other worlds is waiting in the wings.
Early in the next century, NASA plans to launch a device into orbit around the sun, at a distance beyond Mars. Known as an "Interferometer," it is a series of mirrors, arranged along a line, that combine their signals as one.
This is a new breed of telescope, complete with infrared detectors, that can read light reflected off the surface of planets.
A space-borne interferometer, multi-mirror telescope, which would allow us for the first time to take a direct picture of an Earth-like planet. At first, it would just be a dot. Then you can take that dot of light and spread it out into all of its colors, blue through red, even to the infrared, and with that spectrum of colors, detect the chemicals that are making up the atmosphere of that planet. By detecting the chemicals, we can look for oxygen, methane, CO2, and so on, and those chemicals will be the signatures of life, if it exists, on those Earth-like planets.
Iím certain that Earth-like planets exist. Iím certain that if you put them roughly at an Earth-sun distance away from its mother star, that water will exist in liquid form and, ah, with a hundred-billion stars serving essentially as a hundred-billion labs in which to run this experiment, I'm sure that life will evolve on some of them.
As for those other worlds we are now discovering, we populate them with the distant hope that the pulse of life is not our planetís alone.
As we extend our horizons, no doubt we will come to see planets -- And life itself -- From a whole new perspective.
From their point of view, their life might, for example, have hydrogen sulfide in its atmosphere and oxygen would be hopelessly inappropriate. And they would say -- say, "Gee, whatís oxygen doing? Thatís poison," whereas we, in looking at them and saying -- seeing hydrogen sulfide, would say, "What's the planet doing with hydrogen sulfide there? Thatís a bad smell." We've got to come to terms with life being so much bigger than anything that we have recognized just by having one set of planets around and one that happens to be at the right temperature here.
Well weíve received hundreds of pictures from children of our planets drawn in crayon.
We can only imagine what technology will someday reveal.
Now a lot of planets have one set of rings... This planet you see, has two rings....theyíre orthoginal to each other.....
This is the planet Zeus; everybody knows the planet Zeus....
Hereís a planet called Columbus, I donít know what that is.
Every child has done something different. Theyt didnít actually just copy each other.
Hereís the famous Unknown planet....lake of mercury....this is a very brilliant child....this child thinks there might be liquid mercury on this planet...
Hereís the famous planet, "Hand."
Hereís the planet "Whatever." You are here, in case you didnít know where you are. And then of course hereís the planet and who knows what this is around it, some coronal hot gases or something...
For about 20-30 years after we stopped believing inmartians, there was a tendency to think that maybe the galaxy is a relatively lifeless place, but now that weíre realizing there are planets out there, that there may be life out there, I think the galaxy is beginning to seem like something of a romantic place again, a place where there might be other intelligences and beings out there perhaps something like ourselves, beings that we can communicate with over -- over the centuries to come.
I would see human beings as occupying not a central place, but not a trivial place either. A sort of intermediate position. We have a place in the universe, we belong to it, we have emerged from the universe as part of a natural process. We're not freaks. But nor are we at the center either. I think that this sort of middle position is actually one to be celebrated, because I think we can feel that the universe is in -- in some sense our home, that weíre meant to be here.
Like an only child, we wish we had company. And we wish, at the same time, to be Creationís one and only. As we continue to search for our place in the universe, all we know for sure is that our imaginations will guide our journey.
If what was called forth in Creation was not just life on this little tiny speck, but life on this speck and that speck and another speck and another, then life is being called -- called forth everywhere and it would give meaning to our existence in not the way that we originally thought we wanted, to be special, but it would make us significant in being the same.
I had one of my most amazing experiences as an astronomer looking at the Milky Way in the Southern Hemisphere. It was glowing, brilliant stars in the foreground, these massive dust clouds. I thought of all the other civilizations that might be floating in it at the same time and I had a vision of one great galactic community and I felt myself to be a citizen not of Santa Cruz or the United States or Earth, but a citizen of the galaxy for the first time.
And, of course, I had to wonder whether or not we would ever fly around it and meet up with all of these other civilizations.
Episode 1: To the Edge of the Universe || Episode 2: Exploding Stars and Black Holes