Kepler's 'Bizarre' Signal Sparks Alien Intelligence Speculation
The fascinating speculation surrounding a recent Kepler observation of a star 1,500 light-years away has reignited questions of alien life in our universe and what it means for future studies.
The fascinating speculation surrounding a recent Kepler observation of a star 1,500 light-years away has reignited questions of alien life in our universe and what it means for future studies.
First I really want to emphasize, as I did in my previous blog about KIC 8462852, that the root cause of a very strange Kepler transit signal is most likely due to natural phenomena. (A transit occurs when an exoplanet - or, in this case, something else - drifts in front of its star and Kepler detects a slight dimming of starlight.) After analyzing the unique transit signal identified as being "bizarre" by the Planet Hunters community, researchers did a thorough job identifying a possible mechanism by which significant and distinct dimming events could have been triggered.
Among the likely natural causes of the star brightness dimming outlined in a paper submitted to the journal Monthly Notices of the Royal Astronomical Society and made available on the arXiv preprint service on Sept. 11, astronomers looked into debris from a possible planetary collision, the presence of circumstellar rings, starspots, and a clump of comets. All possibilities were investigated, but all were unsatisfactory, except for the latter.
The comet clump explanation seems to answer many of the mysteries about the strange transit signal. A nearby star, only 1,000 AU from KIC 8462852, could have caused some gravitational perturbations during close approach, possibly sending a swarm of comets toward the star, blotting out up to 22 percent of the star's light from Kepler's view.
The exocomet explanation seems reasonable. Although exocomets have been detected around other stars in the past, this would be the first detection of a vast clump of comets big enough to significantly dim the light of a mature F-type star (around 50 percent larger than our sun).
However, an observation of this kind would have to be an incredible stroke of luck; for us to have a NASA space telescope looking in the right place at the right time of this rare collection of comets to pass in front of one star of only 150,000 stars in Kepler's field of view (over a very short time period of 4 years), is crazy lucky.
But just because it's a serendipitous observation doesn't mean it's not caused by comets; we were just really, really lucky to see it.
Wait, There's More It is a great piece of research that stands by itself, an outstanding discovery first by citizen scientists poring over publicly-available data and confirmed by an international collaboration of professional astronomers.
But then, on Tuesday, an article appeared in The Atlantic; an article that provided a further look into the scientific process of seeking out more extreme possibilities. Once again, for the commenters who were upset at my blogging about these alternate hypotheses, I am in no way concluding that the transit signal observed from KIC 8462852 isn't caused by comets or some other natural phenomenon that we haven't accounted for. I'm exploring a possible avenue of investigation that the astronomers involved in the original research are exploring themselves.
Post-doctorate researcher Tabetha Boyajian, at Yale University and lead author of the original paper, spoke with The Atlantic's Ross Andersen, mentioning that she was currently considering "other scenarios" for the strange transit pattern. And, after sharing the data with Penn State University astronomer Jason Wright, who is planning a follow-up publication, one of those other scenarios came to light: the strange transit signal from KIC 8462852 might be caused by a huge artificial structure.
Excerpt from The Atlantic article:
Wright and his co-authors say the unusual star's light pattern is consistent with a "swarm of megastructures," perhaps stellar-light collectors, technology designed to catch energy from the star.
As discussed in Wednesday's Discovery News report, should this signal really be artificial, it could be the first evidence of an advanced alien intelligence that is well on its way to becoming a Type II Kardashev civilization. This is a remote possibility but if all other explanations are exhausted, why not test the alien hypothesis?
Alien Speculation So, what's next? Unfortunately, with Kepler's primary mission over, we only have 4 years of transit data from KIC 8462852 and only 2 key transit events to study. The first dip in starlight occurred for one week in 2011 and then the second significant event was actually a series of variations over the course of a few months in 2013. That's all we have for now.
The researchers are now hoping to get some observing time on a radio observatory to "eavesdrop" on the star in the hope of carrying out a "directed SETI" campaign, hunting for artificial radio signals emanating from the star system. If they draw a blank on this observing run - and, let's face it, the chances of detecting alien communications are still as slim as ever - it doesn't necessarily mean the "structure" isn't artificial, it could just mean that this hypothetical race isn't communicating via radio waves... or it could mean the alien civilization is no longer there.
Our galaxy, which contains hundreds of billions of stars and countless more planets, is over 13 billion years old. The human race has evolved in the tiniest fraction of this time and modern astronomy has only just opened our eyes to the cosmos over the last couple of hundred years. The likelihood of seeing a thriving civilization of advanced extraterrestrials building some kind of solar array around KIC 8462852 at this precise moment in time is extremely tiny. So it is more likely that if the radio signal hunt turns up empty handed, but the object is proven to be an artificial megastructure, it could be the remnant of a civilization that has come and gone - it could be a huge artifact of a bygone alien age.
Seeking out alien artifacts is not a new idea. The Search for Extraterrestrial Artifacts (SETA) and, indeed, the Search for Extraterrestrial Technology (SETT) are both variations of the Search for Extraterrestrial Intelligence (SETI) theme and one such project recently concluded that our local galaxy is devoid of advanced alien beings that can harness all the energy from their star.
Coincidentally, British theoretical physicist Stephen Hawking re-iterated his views on encountering an alien race in a recent interview. Hawking has warned against transmitting signals into space before, lest we get noticed and invaded/assimilated/blended by vastly more powerful entities. For those that have expressed concern about a potentially aggressive race of aliens sending an armada of battleships at Earth from KIC 8462852, it's worth remembering that we are seeing the light from the star that was generated 1,500 years ago - it's 1,500 light years away, so it's taken light that long to travel the distance. If, 1,500 years ago, that hypothetical alien race noticed Earth, it wouldn't have detected any transmissions (radio or otherwise) - as advanced as the Roman Empire was around 500 AD, it's highly doubtful that anything outwardly resembling an intelligent species would have been noticed at those interstellar distances.
But what of our resources? Earth, after all, occupies the habitable zone of our star and it has done for a few billion years, possessing liquid water in abundance, now supporting a thriving biosphere - perhaps a space-traveling alien race would want to take up home here? Well, to our hypothetical alien explorers/conquerors, the sheer distance between us would be Earth's greatest defense. Regardless of how advanced a civilization becomes, they are still bound by physics and limited by the speed of light. A trip that distance (assuming the warp drive isn't out there, somewhere) would take hundreds of thousands or even millions of years by "conventional" means.
Also, as the Kepler mission itself is teaching us, our galaxy is filled with a bountiful array of small rocky worlds. It seems, in this early stage of discovery at least, that there are many small worlds orbiting within the habitable zones of their stars, potentially also with global oceans of liquid water. If they wanted to invade purely for our resources, there's probably some easier-to-reach options out there.
All these ideas are pure conjecture as we don't have the faintest clue as to whether there's any other life form out there, let alone an intelligent civilization building solar energy collectors around a certain F-type star in our little corner of the galaxy. But as we look deeper into the cosmos through an increasingly defined lens, we're changing our perspective on the universe.
Although this new research into KIC 8462852 most likely has an elegant, natural explanation, probably centering around a huge clump of comets, speculation about the possibilities of of life in our galaxy is no bad thing. Indeed, the reasons why we haven't detected anything even remotely intelligent elsewhere in the galaxy is a paradox that defies our very existence.
If life is inevitable in the universe, and we know the ingredients are out there to spark life, where is everybody? Now we are developing the technology to directly probe the orbits around other stars in the shape of Kepler and other planned exoplanet hunting missions, we are in a very privileged time for our civilization; we can speculate, hypothesize and test our theories about alien life with precision that, until only a few years ago, we wouldn't have dreamed.
So on this voyage of discovery, right at this moment, a few astronomers are investigating a couple of bizarre light curves discovered by citizen scientists and analyzed by astronomers to see if something artificial is at play. In my view, this is an awesome thing.
Exoplanets are mysterious, bizarre and some are just a little bit scary. With the help of the Kepler space telescope and advanced ground-based exoplanet-hunting techniques, for the first time we're directly observing a veritable menagerie of alien worlds, making this a historic time in human history. Through exoplanetary studies, we're beginning to even understand our place in the Universe. However, despite all the excitement, many of these alien worlds seem downright weird. Some are being called "impossible," while others sound like they belong in the storyline of the next low budget slasher flick. Phantom worlds are on the prowl; ghosts dance in exoplanets' atmospheres; entire worlds are even having their guts ripped out! Welcome to the world of Exoplanetary Horror, a rundown of the scariest alien worlds likely to frighten even Captain Jean-Luc Picard back into his shuttlecraft.
The majority of exoplanets discovered thus far are gas giant worlds, often many times the size of Jupiter. Sometimes these worlds will orbit so close to their host stars that they are called "hot-Jupters." So, if you were an alien creature living in the gaseous atmosphere of one of these hellish worlds, where would you hide to get away from the searing heat? Well, you'd navigate away from the star, toward the night-side of the exoplanet, right? Bad move little floating alien! An exoplanet recently discovered by the Spitzer space telescope discovered a mysterious "hot spot" in its atmosphere, a full 80 degrees offset from the star. This means that the hottest part of the atmosphere isn't on the day-side (with the star directly overhead) but toward the night-side at sunrise and sunset -- where the temperatures exceed 1,000 degrees Celsius! That's hotter than molten rock! It is theorized that this extreme hotspot is caused by ultra-fast winds blasting like a blowtorch around the planet away from the star, generating shocks that boost atmospheric heating. So, unless you wanted to vaporize faster than a vampire bathed in sunlight, that's where you wouldn't want to be.
One would think that the only thing that makes exoplanet Fomalhaut b scary is the fact that it orbits within a dusty cloud that looks exactly like the evil "
" from the epic trilogy The Lord of the Rings. But no, the alien world is more subtle than that. It may not exist. Conflicting studies suggested that Fomalhaut b may be a ghost as it has exhibited strange movement not fitting with it being an exoplanet. But -- like the ghostly Flying Dutchman forever lost at sea, never to make it to port -- astronomers think they've spotted Fomalhaut b adrift in its ocean of dust once more. We'll have to wait and see until the world is either confirmed, or forever be a ghost story.
Recent studies have identified a new classification of exoplanets -- they're small, rocky and have hellish orbits around their host stars. What's more, they shouldn't even exist. Kepler-78b is one of these worlds that orbits a star some 400 light-years away. It is of the approximate size and mass of Earth and likely contains an iron core. But that's where any similarity ends. This is a lava world, suitable only for fire-dwelling demons, or the devil itself. Interestingly, there is no known planetary evolution theory that can explain these worlds.
In the cult sci-fi horror flick Chronicles of Riddick: Pitch Black, anti-hero convict Riddick (Vin Diesel) crashes onto a rather unsettling alien planet infested with horrific flying bat-like creatures hell-bent on eating Riddick and the rest of the surviving crew. But it's not as simple as that -- these flying nasties only come out at night. Cue the screaming, running and killing... all in the dark. As Pitch Black proves: at night, horror comes out to play. And in the case of an exoplanet called TrES-2b, script writers' imaginations would run wild as to what sci-fi horror could be waiting deep in its inky atmosphere. The world is literally pitch black -- darker than coal. What's more, as it orbits so close to its star, TrES-2b is tidally locked, meaning one side of the exoplanet is in continuous nighttime. I wonder how Vin Diesel would deal with that.
Nobody likes stuff that oozes. Especially when it's oozing brain matter, blood, slime or some mystery extraterrestrial fluid that inextricably likes to cuddle its pray's face. So, on that note, welcome to 55 Cancri e! It's a whole exoplanet that -- you guessed it -- oozes. It could be the home world of The Blob, or perhaps a place where the Star Trek baddie Armus likes to vacation. But why is this world oozing? As this super-Earth exoplanet has such a tight orbit with its star and observations suggest there must be a huge quantity of some unidentified liquid inside its body, any fluids that appear on its surface will likely be solvents that have oozed from below.
Don't open the Ark of the Covenant! If you remember that famous "melting Nazi" scene from the classic Indiana Jones and the Raiders of the Lost Ark, you'll know exactly what I mean. The iconic scene included angry spirits, melting faces and the exploding head of Jones' nemesis Dr. René Belloq. At the time, it was cutting-edge horror animation, but imagine if you faced the rage of the Ark's spirits every... single... day. One world with a perpetual "melting face" is poor old CoRoT-2a, a world facing its own angry spirits from its host star in the form of powerful X-rays. The radiation is so strong that scientists using the Chandra space telescope think 5 million tons of material is being ripped from the world every second! If that's not a tortuous death, I don't know what is.
Ever wanted to know what it must feel like to be boiled alive? Well, try landing on this exoplanet and you'll quickly find out! At face value, Gliese 1214 b may not sound too bad -- it's a "super-Earth" rich in water. However, astronomers have noticed that this isn't the kind of water you'd want to be drinking. The bone-crushing pressures and eyebrow-singing temperatures maintain this water in a plasma state, creating a dense, deadly ocean at the bottom of its atmosphere. It's basically an extreme exoplanetary pressure cooker.
"I see dead people," said Haley Joel Osment in the 1999 ghost film The Sixth Sense when he broke the news to Bruce Willis that he has a rather unhealthy habit of seeing... well... dead people. [Spoiler!] It turned out that Willis was also one of those dead people. Now, combine this with ancient folklore that said the aurora was in fact dancing souls of the dead (forget the aurora is, in reality, a beautiful side-effect of solar plasma raining through the upper atmosphere) and what do you get? We see dead people too! (It's a stretch, I know.) So, if the aurora is interpreted as the souls of the dead, spare a thought for what you'd see if you lived on an exoplanet with a global magnetic field, orbiting close to its host star. Scientists think that closely-orbiting "hot Jupiters" will experience awesome auroral displays as plasma from their nearby star floods their atmospheres. The result? Aurorae 100-1000 times brighter than the displays we see on Earth -- like ghosts dancing all over the planet.
Loners. Particularly weird loners with unpronounceable names. Carrying an axe.
. Yep, that's scary -- a storyline that has been used for generations to scare the pants off cinema-goers. So, what about loner exoplanets? There are thought to be loads of exoplanets out there, but a few of them are too small and too distant from their host stars to be detected by conventional telescopes. However, sometimes, astronomers get lucky and spot one of these extra-solar loners. Take MOA-2009-BLG-266Lb for example. (Sounds like a weirdo, right?) It's a "super-Earth" that would normally orbit its star too far away to be spotted. But, with the help of general relativity, its 10-Earth mass bulk bends spacetime just enough to focus its star's light when seen from Earth. This is known as a "microlensing" event, and though rare, it can pick out tiny rocky worlds floating far from home. And then there's the case of PSO J318.5-22 (pictured here) -- a free-floating exoplanet that appears to have lost its parent star all together. But then again, it might not be a planet at all, more of a "failed star." That moniker shouldn't give this lonely guy self esteem issues at all... These exoplanetary loners may not be carrying an axe, but they do pose many questions as to how they evolved so far away from their stars (if they had stars in the first place, that is).
When Jeff Goldblum grew spiky hair and other weird fly-like appendages in the human-experimentation-gone-wrong horror movie The Fly, needless to say, his friends grossed out. I'm sure exoplanet HD 209458b would sympathize with Goldblum's predicament. As it's orbiting close to its star, powerful stellar winds are stripping its atmosphere into space, creating a comet-like tail. HD 209458b must be wondering why its exoplanet friends are pointing, nervously laughing and slowly backing away.
Sure, the idea of a "diamond exoplanet" may sound luxurious. Sadly, life as we know it (i.e. you) probably wouldn't get much of a chance of walking barefoot across diamond-enriched beaches. Scientists have modeled carbon-rich worlds (as opposed to silicate-rich worlds like Earth) to find out that the carbon that formed the planets in carbon-rich stars likely sucked out all of the oxygen during the stars' formative years. With no oxygen, water couldn't form (a molecule that consists of two hydrogen atoms and an oxygen atom). Therefore, carbon worlds (the most exotic of which may be rich in diamonds) are dead, parched worlds with no hope for life as we know it. Bummer.
In a star system, far, far away, an exoplanet is being menaced by the gravitational pull of another world, causing it to slow down and speed up as it orbits its parent star... And yes, this is a real phenomenon, and not just a butchered opening for a Star Wars spin-off. Some 650 light-years away, an exoplanet orbits a sun-like star called Kepler-19. The world, Kepler-19b, has a very strange orbit in that sometimes it speeds up, completing its 9 day orbit 5 minutes fast, and at other times, it will complete an orbit 5 minutes slow. This orbital weirdness is all down to an invisible world whose gravitational influence is tugging at Kepler-19b. "Transit timing variations" may sound a little spooky, but the method has since been used in other star systems to detect the presence of hidden, phantom worlds.
"Look out! You're about to get--" *BOOM* It's the classic cliffhanger: there's an exoplanet, minding its own business, floating way too close to its parent star when, literally, all hell breaks loose. In the case of HD 189733b, located some 60 light-years from Earth, its star decided unleash a powerful flare that the Hubble Space Telescope was able to see. If you needed an example of the Gates of Hell opening, this is it. What's more, the exoplanet suffered horribly. Hubble was able to discern massive quantities of hydrogen blast from the exoplanetary atmosphere. By astronomers' reckoning, such powerful displays of star fury may explain why we've been discovering small rocky worlds so close to other stars -- perhaps they are the charred husks of what were once mighty gas giants. Nice. Exoplanetary corpses.
Zombies are awesome for chopping up, shooting or dismembering. And if we're to believe all those George Romero movies, no matter how you slice 'em and dice 'em, a zombie "World War Z"-like apocalypse is inevitable (unless you can destroy their brains quickly). So what has this got to do with exoplanets? Well, it depends how you interpret this little story, but it certainly sounds like we have a zombie exoplanet on our hands (figuratively speaking). Twelve years ago, astronomers using data from the Hubble Space Telescope thought they saw an exoplanet orbiting a star. On closer inspection, other astronomers couldn't find the world and declared the exoplanet dead. But in 2009, it appears the exoplanet, called TMR-1C, is back from the dead having been spotted by astronomers using the Canada-France-Hawaii telescope. OK, so it's not much of a zombie exoplanet -- and it's certainly not a reanimated corpse -- it was just hiding.
Sure, some exoplanets may have some horrific qualities, but more often than not it's their parent stars that have a nasty side. Take white dwarfs -- they may sound cute, but their tidal forces are living hell to anything orbiting them. When a sun-like star approaches death, it puffs up into a red giant, shedding its outer layers. What's left is a little shining jewel of a star -- a white dwarf -- with any planets and asteroids that survived the stellar death. Unfortunately for anything in orbit, if they get too close, the tidal shear of the tiny star will literally shred anything that gets too close... much like a blender. Astronomers have even used the blended debris surrounding white dwarfs to decipher whether any rocky planets were once in orbit. Funny thing is, in a few billion years time, alien astronomers may be looking at the dusty remains of our planet drifting around our dead, white dwarf sun.