The Real Science of Avatar's Pandora
By Charles Q. Choi | Excerpt: space.com
The movie is set on the fictional Pandora, one of the many moons of a fictional Saturn-sized gas giant, Polyphemus, which is located in the real Alpha Centauri system, which at nearly 4.4 light-years away is the closest star system to Earth.
While astronomers have yet to discover moons beyond our solar system, they expect to. And the Alpha Centauri system could be a place worth looking. The larger of the two real, sunlike stars that make up this alien system, Alpha Centauri A, is the fictional Pandora's sun.
In reality, scientists might soon be able to detect habitable moons with the James Webb Space Telescope and also study their atmospheres for key life-related gases such as oxygen, and water vapor.
Tropical rainforests cover most of Pandora's continents, which suggests its mother planet must be fairly close to its sun to take advantage of its light.
A few years ago, this might have seemed implausible, but most of the alien planets scientists have discovered so far are in fact gas giants that are exceedingly close to their stars. However, life on a gas giant's moon might present a host of challenges.
Jupiter's moons exist within an intense radiation belt of electrons and ions trapped in the planet's magnetic field, and Saturn's gravitational pull leads to extraordinary tidal effects that may have once ripped apart nascent moons to produce its rings, and today can drive winds and volcanic eruptions on its moon Titan.
The draw that Pandora has for humans is a naturally occurring ore dubbed "unobtanium," an old in-joke in science fiction for materials with physically impossible qualities. (Technically, since it's a mineral, it might better be called "unobtainite," but that's a pretty nerdy quibble.)
Unobtanium is the best superconductor known, and apparently works at room temperature. Just as real-world superconductors can float in the presence of a magnetic field, mountains on Pandora apparently loaded with unobtanium can float in the powerful magnetic pockets that dot the moon's surface.
The films show these magnetic fields can interfere with technology, just as they would in real life — although, apparently, not whatever wireless links which allow the main characters to link with their "avatars."
Avatar: A New World That NASA Is Ignoring
By Keith Cowing | Excerpt: spaceref.com
[Link no longer available]
"Avatar", a film by former NASA Advisory Committee member James Cameron, will debut across the planet on 18 December. Widely hailed as "ground breaking" the film may well push the boundaries of what can be portrayed on the big screen.
The film centers around humans mining precious materials on a world in the Alpha Centauri star system - and the inevitable conflict that arises with the local (sentient) inhabitants. The film delves into a wide range of issues that intersect with what NASA's Astrobiology Institute and Exobiology Programs have looked into in one way or another.
Unparalleled simulations of an extrasolar planet with a whole new ecology - but it would seem that NASA is not really interested in this film.
NASA has made a variety of attempts to collaborate with Hollywood in the past to promote movies that have some resonance with what NASA does (or what people think it does). Recent examples include "Buzz Lightyear" and "Planet 51".
Some of these collaborative efforts have resulted in substantial public interaction - often with people who would not normally stop to ponder what it is that NASA does or how it might relate to them. On the other hand, NASA has also engaged in a campaign to refute the utter stupidity contained in the recently released film "2012".
Given that NASA is not afraid to weigh in on both positive and negative (stupid) films, is NASA going to take advantage of this film's debut to engage the public on issues relevant to Astrobiology and life in the universe? So far, I am told that the answer is "no".
If NASA can spend taxpayers dollars to shoot down stupid movies and fly action figures and DVDs in space to promote a film, then you'd think that they'd also consider something focusing more on hard science.
With regard to "Avatar", were NASA so inclined to do so, one outreach effort might include materials distributed in (online and in person) in coordination with the film that focus upon how topics of interest to both Astrobiologists - and the general public - are addressed in this movie. So far NASA has told me that no outreach activities in connection with this film are being considered.
If that ends up being what happens, then I think that NASA will have wasted a sterling opportunity to engage the public in a meaningful way - using a film that hundreds of millions of people will see - one that blends awe and wonderment of tomorrow with the things that are being done - by NASA - today.
"And one thing that seems certain is that the alien world depicted in the film, Pandora, is poised to join the ranks of sci-fi's best designed and most epically memorable planets. " . . . IGN.com
Articles exploring Avatar's Pandora. Some articles contain excerpt highlights, click on the source link for the complete article.
The Moon Pandora and it's Floating Mountains
By Mark Sappenfield | Excerpt: abcnews.go.com
[Link no longer available]
The producer of "Avatar" is fond of saying that writer and director James Cameron does not write science fiction, he writes science fact.
From the reclining, cup-holdered seat of a local multiplex, that seems a generous statement. Neither mountains floating in midair or fauna that lights up like the Las Vegas Strip at night would seem to have the slightest foundation in reality. And yet they do.
To be sure, Mr. Cameron likes to bring his fair share of Hollywood to the cosmos, painting his scenes with the brush of fantasy. But beneath some of his most outlandish visions is often a kernel of scientific possibility.
The Floating Hallelujah Mountains
The topic of how an entire mountain range can bob over the landscape like corks is never explicitly addressed in the film, yet the explanation is woven throughout the story. It all has to do with superconductors. When superconductors are in the presence of a magnetic field, they can float. "Avatar's" alien world of Pandora, it turns out, is simply a massive superconductor. At the very beginning of the story, we are told that humans have come to Pandora to mine unobtanium.
Unobtanium is the ultimate superconductor. (The very name, "unobtanium," is a nod to sci-fi afficionados, who coined the word to describe a material with mythical properties.) In Cameron's world, unobtanium can conduct electricity without resistance at room temperature; the best current superconductors work only when the temperature is below minus 200 degrees F. The discovery of unobtanium, which exists only on Pandora, revolutionized technology on Earth, the story goes, and the future human economy is dependent upon it.
On Pandora, however, entire mountains loaded with unobtanium float in the world's massive magnetic field. In a glimpse of how thoroughly Cameron has thought through the science behind his creation, he and his team have written a 380 page "Pandorapedia" that explains (among other things) the tectonics behind how such mountains could form.
Natural Phenomena Inspire Cameron's Visions
In effect, they crumble upward. This happens because Pandora is not a planet but a moon of a gas giant the size of Saturn – the fictional planet Polyphemus. Moons of gas giants are constantly tugged and deformed by the stresses of gravity. One of Jupiter's moons, Io, is pulled so violently by the gravitational forces of both Jupiter and Jupiter's other large moons, that it has ground tides – the ground literally rises and falls like a sea tide on Earth.
On a second moon of Jupiter, Europa, these tidal forces have heated the interior of the moon to the point that part of its crust has melted, creating a sea of liquid water beneath a surface of ice, scientists say. On Cameron's Pandora, those tidal stresses have fractured the landscape, and, in the case of the Hallelujah Mountains, sent it up into the sky. A companion book to the movie explains the larger process: "This … energy drives continental drift at a much faster rate than on Earth, causing tectonic plates to fracture more extensively because of the increased stress."
Cameron's fascination with the deep sea has already led to one of the most successful films of all time: "Titanic." It appears to have shaped "Avatar," too. The oceans' depths have a curious answer to sunlight, which has never been seen there. It's called bioluminescence – organisms' ability to create their own light. Fireflies are perhaps the most obvious example, but the bioluminescent fish of the deep sea tell a different story – that nature, when deprived of light, sometimes creates its own.
On Pandora, where the nights can be many Earth days long, Cameron has suggested that an entire bioluminescent ecosystem could emerge. This is where Cameron's decision to make Pandora a moon – and not a planet – comes in. Moons, including Earth's, are typically "locked" to their planets, with one side eternally facing the planet and one side eternally facing out into space. What this means is that one day on a moon equals the time it takes to orbit its parent planet – a long time.
Home Sweet Moon
But could a moon hold life? Potentially, yes. Actually, making Pandora a moon appears to be an acknowledgment of recent science. Astronomers are still looking for planets like Earth – small and rocky – within the so-called "Goldilocks zone": Not so close to its star that its life-giving water evaporates, yet not so far away that it freezes into ice. But small planets are hard to find. Instead, scientists have found gas giants like Saturn in the habitable zone around stars. Those planets are not inhabitable – but their moons could be.
That makes moons a good place to start looking for alien life. "All of the gas giant planets in our solar system have rocky and icy moons," Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., told AP. "That raises the possibility that alien Jupiters will also have moons. Some of those may be Earth-sized and able to hold onto an atmosphere."
The problem is that gas giants emit tremendous amounts of radiation. The daily radiation on Jupiter's Io, for instance, is 4,000 times the lethal dose. Yet here again, Cameron uses science to solve science's own problems. The robust magnetic field created by Pandora's superconductivity deflects the radiation. At one point in the film, a spectacular aurora dances overhead. Striking filmmaking, yes.
Pandora: A look at Polyphemis' Exomoon
By Larry Klaes | Excerpt: centauri-dreams.org
When the United States was preparing to send the first humans to Earth’s largest natural satellite in the 1960s with Project Apollo, there were numerous scientists of the day who protested this effort. They felt that knowledge and even surface material could be gathered from the Moon far more cheaply and efficiently with automated probes than with astronauts.
On a technical and pragmatic level, those scientists were essentially correct. But as with many things in human society, the primary reasons for the existence of Apollo were about politics and power, specifically in this case to show up America’s chief Cold War rival, the Soviet Union, in the vast arena of space.
Most astronomers of the era eventually realized that if they wanted to learn a lot about the Moon and beyond, they had to jump on the relatively expensive and resource-intensive government-sponsored bandwagon or end up literally left behind in a cloud of smoke. Apollo may not have been the most efficient and productive way to reveal the ancient secrets of our nearest celestial neighbor, but it did work in the end.
This is how I have decided to approach the currently quite prominent existence of the new science fiction film Avatar by James Cameron in terms of educating the general public when it comes to the film’s themes of exobiology, exomoons, exoplanets, and human interaction on an interstellar scale.
Interstellar Ideas and the Public
Avatar is hardly the most efficient or inexpensive way to bring these major topics to a wide swath of society. However, just as the money, resources, and technology poured into Apollo brought hundreds of pounds of lunar rock and other invaluable space science data to Earth – as compared to the few ounces of lunar regolith retrieved by the three successful automated Soviet Luna craft during the 1970s – Cameron’s latest cinematic extravaganza will probably do more to make people aware and think about these literally universal ideas than dozens of books, articles, and documentaries on the same subject.
I and others may not agree with this, but the reality is that many people do get much of their “education” about the world and especially science from film and television, which is not obliged to be any more accurate and educational than it has to when their primary goal is to entertain in order to make a profit. So to dismiss Avatar out of hand because it may have a less than original plot and characters of limited depth is to dismiss as well a major opportunity to guide a public that may otherwise never bother to contemplate and confront the issues raised in this film.
Astronomers have detected over 400 alien worlds since 1995. Every day we come closer to finding the first Earth-type exoplanets and the first exomoons. When this happens, many consider it a given that various space agencies will begin to make serious efforts to reach those distant places in the galaxy, first to study them and then to send humans there in person to colonize. Just as other influential films have actually played a role in inspiring or deterring people from grand efforts, Avatar will probably be cited as either one of the catalysts for launching humanity to the stars or holding us back out of fear from alien unknowns or what we might do to others unlike us.
The realm of Avatar is the moon Pandora, which circles a gas giant world named Polyphemus that in turn orbits the star Alpha Centauri A, among the closest of suns to Earth at just 4.3 light years, or about 25 trillion miles. Though in reality Jupiter-type exoplanets have not been detected in the Alpha Centauri system, which implies that such bodies may not exist, Avatar does help to make its audiences aware of the concept of moons as places for life to form and evolve, since most of the exoplanets found so far are giant worlds, many of them larger than Jupiter.
Thoughts on the Setting
As we have seen with our own Jovian planets since the days of the twin Voyager space probes, gas giant worlds do have retinues of large and dynamic moons, some of which may be homes for simple organisms. There is no reason not to think that alien gas giants might have exotic companions as well, though whether they would be like the residents of Pandora is much too early to say.
On the subject of living on the moon of a gas giant planet: Note how huge Polyphemus looms in the skies of Pandora as we are witness to throughout the film. It is certainly a very awe-inspiring and aesthetically pleasing image, enhancing the alienness of the moon and its inhabitants. However, I would think that being so close to a gas giant would cause all sorts of geological turmoil, which in turn would greatly upset the balance of life on Pandora, perhaps even to keep it from becoming complex.
An Exomoon’s Culture
Putting aside whether or not a tropical rainforest type ecology could evolve on a moon being so close to a gas giant planet, I had to wonder why the alien intelligence on Pandora, the Na’vi, did not seem to focus much attention on such an incredible sight as the planet Polyphemus, which seems to take up most of the sky over Pandora. Now granted I know the Na’vi are aliens, but since they also bear more than a slight resemblance to aboriginal peoples on our planet, I am surprised they didn’t focus at least some of their culture on the great world hanging over their heads.
Avatar's moon Pandora could be real
In the new blockbuster Avatar, humans visit the habitable - and inhabited - alien moon called Pandora. Life-bearing moons like Pandora or the Star Wars forest moon of Endor are a staple of science fiction.
With NASA's Kepler mission showing the potential to detect Earth-sized objects, habitable moons may soon become science fact. If we find them nearby, a new paper by Smithsonian astronomer Lisa Kaltenegger shows that the James Webb Space Telescope (JWST) will be able to study their atmospheres and detect key gases like carbon dioxide, oxygen, and water vapor.
"If Pandora existed, we potentially could detect it and study its atmosphere in the next decade," said Lisa Kaltenegger of the Harvard-Smithsonian Center for Astrophysics (CfA).
So far, planet searches have spotted hundreds of Jupiter-sized objects in a range of orbits. Gas giants, while easier to detect, could not serve as homes for life as we know it. However, scientists have speculated whether a rocky moon orbiting a gas giant could be life-friendly, if that planet orbited within the star's habitable zone (the region warm enough for liquid water to exist).
"All of the gas giant planets in our solar system have rocky and icy moons," said Kaltenegger. "That raises the possibility that alien Jupiters will also have moons. Some of those may be Earth-sized and able to hold onto an atmosphere." Kepler looks for planets that cross in front of their host stars, which creates a mini-eclipse and dims the star by a small but detectable amount. Such a transit lasts only hours and requires exact alignment of star and planet along our line of sight. Kepler will examine thousands of stars to find a few with transiting worlds.
Once they have found an alien Jupiter, astronomers can look for orbiting moons, or exomoons. A moon's gravity would tug on the planet and either speed or slow its transit, depending on whether the moon leads or trails the planet. The resulting transit duration variations would indicate the moon's existence. Once a moon is found, the next obvious question would be: Does it have an atmosphere? If it does, those gases will absorb a fraction of the star's light during the transit, leaving a tiny, telltale fingerprint to the atmosphere's composition.
The signal is strongest for large worlds with hot, puffy atmospheres, but an Earth-sized moon could be studied if conditions are just right. For example, the separation of moon and planet needs to be large enough that we could catch just the moon in transit, while its planet is off to one side of the star. Kaltenegger calculated what conditions are best for examining the atmospheres of alien moons. She found that alpha Centauri A, the system featured in Avatar, would be an excellent target.
"Alpha Centauri A is a bright, nearby star very similar to our Sun, so it gives us a strong signal" Kaltenegger explained. "You would only need a handful of transits to find water, oxygen, carbon dioxide, and methane on an Earth-like moon such as Pandora." "If the Avatar movie is right in its vision, we could characterize that moon with JWST in the near future," she added. While alpha Centauri A offers tantalizing possibilities, small, dim, red dwarf stars are better targets in the hunt for habitable planets or moons.
The habitable zone for a red dwarf is closer to the star, which increases the probability of a transit. Astronomers have debated whether tidal locking could be a problem for red dwarfs. A planet close enough to be in the habitable zone would also be close enough for the star's gravity to slow it until one side always faces the star. (The same process keeps one side of the Moon always facing Earth.) One side of the planet then would be baked in constant sunlight, while the other side would freeze in constant darkness.
An exomoon in the habitable zone wouldn't face this dilemma. The moon would be tidally locked to its planet, not to the star, and therefore would have regular day-night cycles just like Earth. Its atmosphere would moderate temperatures, and plant life would have a source of energy moon-wide.
Newly Discovered Exoplanets Point the Way
to Avatar's Pandora
By Christine Fall | Excerpt: amctv.com
[Link no longer available]
In case the 3D effects and out-of-this-world action scenes haven't convinced you Avatar is the must-see movie of the year, real science is adding to the excitement.
On Monday, researchers announced the discovery of as many as six low-mass planets orbiting two nearby stars that add weight to the promise of detecting habitable worlds within the next few years.
It's the perfect promotion for the spectacular movie that, as ComingSoon.net explains, "makes you think what could possibly be out there in space waiting to be discovered on another planet."
What makes the discovery so exciting is that two of the planets are "super-Earths" (more massive than Earth but less massive than Uranus and Neptune) and they're the first ones ever found around a Sun-like stars. "If we want to one day find habitable planets that are really like the Earth in systems that are really like ours," explains team member Chris Tinney of the University of New South Wales, "then those are the sorts of stars we need to be able to find low-mass planets around."
Three of the newfound planets, with masses ranging from about 5 to 25 times that of Earth, orbit 61 Virginis (our stellar neighbor most like the Sun in terms of age, mass, and other essential properties) and have great potential for alien life, bioluminescent or otherwise. Unfortunately, even though the star is one of the closest to our solar system, at 28 light-years away, the system remains far out of reach. Even fictional spaceships can't make that trip: It would take Avatar's ISV Venture Star over 40 years to make the journey.
But that doesn't mean the only other world you'll ever see in 3D is the one James Cameron created for the Na'vi. "Neptune in our Solar System has a mass 17 times that of the Earth. It looks like there may be many Sun-like stars nearby with planets of that mass or less," says Tinney. "They point the way to even smaller planets that could be rocky and suitable for life." Perhaps even ones, scifi fans would hope, located in Alpha Centauri. The planet hunters also found a 7.5-Earth-mass planet orbiting HD 1461, another near-perfect twin of the Sun located 76 light-years away.
They can't tell if it is a scaled-up version of Earth, composed largely of rock and iron, like Uranus and Neptune, composed mostly of water, or like the fictional Pandora composed of unobtainium and other valuable minerals that will help us survive in the future. Given that Cameron's biography is called The Futurist and that he has a proven track record of making science fiction that turns out to be more fact than fiction, there's a good chance the planet is covered in Hometrees and features floating mountains.
Just as Cameron developed new motion-capture tech to create Pandora, today's researchers are developing new detection tech to find it. By combining data gathered at the W. M. Keck Observatory in Hawaii and the Anglo-Australian Telescope (AAT) in New South Wales, Australia, they inferred the existence of the planets by noting the worlds' gravitational effects on the parent star's orbit.
"What is truly exciting about the current ground-based radial velocity detection method is that it is capable of locating the very closest potentially habitable planets," says team member Gregory Laughlin, professor of astronomy and astrophysics at UCSC. By watching Avatar we'll have an idea of what we might find once they pin down a nearby location. We just need to figure out how to get out there.
Sci-Fi's Coolest Worlds
Pandora makes IGN's list
With James Cameron's long-awaited return to genre filmmaking, Avatar, hitting screens just two months from now, we're starting to get a sense of what the top-secret film is going to look like. And one thing that seems certain is that the alien world depicted in the film, Pandora, is poised to join the ranks of sci-fi's best designed and most epically memorable planets.
That's got us thinking lately about the coolest worlds of genre cinema. We've seen a lot of alien landscapes and futuristic planets over the years, but which ones are the major worlds that have been most influential in sci-fi film? So with that question raised, take a look back with us at a few of our favorites -- the awesome alien lands that Pandora is poised to join come this December.
Avatar's Pandora: Pandora is a lush, tropical sort of world that looks to be equal parts Eden, FernGully, and Star Wars (with a little bit of Endor, Yavin, and Dagobah all rolled into one). Filled with fearsome creatures and hot, blue, alien cat-women, Pandora is the kind of place where you can fly on a pterodactyl, inhabit your own personal Thundercat avatar, and lead the charge to save an entire race of honorable and noble creatures.
And then there's Cameron's reportedly groundbreaking technology which he developed to create this world and its inhabitants... suffice to say, we're there in December. The other sci-fi worlds that made their list: Dune's Arrakis, The Worlds of Star Wars, Star Trek's Genesis Planet, Alien's LV-426, Solaris, Cybertron, and Alternate Earths (Blade Runner / Planet of the Apes). Click on the source link above for the complete article.