How Astronomers Plan to Solve the Mystery of the “Alien Megastructure Star”

By Corey S. Powell | July 31, 2016 11:10 pm
In the constellation Cygnus, one faint star displays enigmatic changes in brightness. Something huge is passing in front of the star–but what? (Credit: Stellaruim, Boyajian et al)

In the constellation Cygnus, the faint star formally known as KIC 8462852 displays irregular, enigmatic changes in brightness. Something huge is passing in front of the star and blocking its light–but what? (Credit: Stellaruim, Boyajian et al)

If you look in enough places, eventually you’ll find something profoundly strange. That’s been a reliable rule of thumb through the history of science, and last year it proved dramatically true again for astronomer Tabetha Boyajian. While digging through data from NASA’s Kepler space telescope, which has been monitoring 150,000 stars for signs of orbiting planets, she realized that one of these things is not like the others. A single star in that set, formally catalogued as KIC 8462852 but informally known as Tabby’s Star, flickers in an inexplicable way: unlike the shadows produced by planets, unlike any known type of stellar pulsation, simply unlike anything seen before.

Tabby’s Star is so unusual that a few scientists, including Boyajian’s colleague Jason Wright, raised the possibility that its flickering is not natural but is due to the presence of an enormous artificial construct. That speculation quickly lent KIC 8462852 another nickname, the “alien megastructure star,” and prompted a flood of breathless news stories; it even got a shout out on Saturday Night Live. Boyajian’s subsequent TED lecture drew even more attention to her star. [Update: A week after I posted this interview, Tabby’s Star star got weirder still: A new study shows that it has been inexplicably getting dimmer over the past three years.]

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Getting Under the Alien Skin of the New ‘Independence Day’

By Corey S. Powell | June 24, 2016 4:01 pm
Aliens arrive with everything cranked to 11 in Independence Day: Resurgence. (Credit: Twentieth Century Fox Film Corporation)

The aliens are back and everything is cranked up to 11 in Independence Day: Resurgence, a 20-years-later sequel. (Credit: Twentieth Century Fox Film Corporation)

If you are looking for cerebral science fiction stories that meticulously explore the outer limits of known science, Roland Emmerich is not your guy. The auteur behind the 1996 alien-invasion movie Independence Day and its new sequel, Independence Day: Resurgence, is all about spectacle over subtlety. (2012 and The Day After Tomorrow are also his handiwork.) Blowing up cities? Check. Sciencing the sh*t out of things? Not so much.

Taken on its own terms, though, the first Independence Day was a lot of fun and—beneath the popcorn-chewing action—smarter than it looked. Emmerich’s best idea was not trying to give his aliens convoluted, ludicrous motivations. Instead he envisioned them as a rapacious swarm, roaming instinctively from planet to planet in search of resources. The sequel maintains that premise and supersizes it, in the inevitable Hollywood style.

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The Billionaire and the Doomsday Dust-up

By Corey S. Powell | May 31, 2016 11:52 pm
Map of "potentially hazardous objects" shows 1,400 such bodies that come unsettlingly close to our planet. (Credit: NASA/JPL-Caltech)

Map of “potentially hazardous objects” shows 1,400 such bodies that come unsettlingly close to our planet. (Credit: NASA/JPL-Caltech)

First of all, let me reassure you that this post has nothing at all to do with Donald Trump. The billionaire in question is not the presidential candidate but Nathan Myhrvold, the former chief technology officer at Microsoft. The doomsday I’m talking about is not political but physical. And the dust-up comes down to a contentious but ultimately quantifiable issue: What is the real risk from asteroid impacts?

In a recent paper, Myhrvold charges that NASA scientists have made some serious errors in calculating the size and properties of the asteroids that come dangerously close to our planet. The specific details are fairly technical (you can read a semi-popular summary of his argument here in PDF form), but the upshot is plain enough. If the estimated asteroid sizes are wrong, so are the associated dangers posed by these objects. That would raise a whole new level of uncertainty around a type of natural disaster that is already the subject of highly polarized hype and dismissals.

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To Planet 9 and Beyond: An Interview with Mike Brown

By Corey S. Powell | April 30, 2016 11:53 pm
A man and his planet: Mike Brown alongside the most likely orbit of Planet 9. (Credit: Caltech)

A man and his planet: Mike Brown alongside the most likely orbit of Planet 9. (Credit: Caltech)

I mean no disrespect when I say that Mike Brown is a man on the edge. In fact, it is one of the highest forms of praise I can imagine. Brown, an astronomer at Caltech, has been one of the most aggressive scientific explorers of the dark, outer boundaries of the solar system. His campaign to extend human vision into the poorly understood region beyond Neptune led to the discovery of a whole menagerie of large object including Pluto’s near-twin, Eris. That work led to the official demotion of Pluto from planet to “dwarf planet.”

Brown has no regrets (he proudly calls himself @plutokiller on Twitter), not because he considers Pluto unimportant but because he considers the whole vast region beyond Neptune so hugely important for understanding the evolutionary history of Earth and the rest of the solar system. Most recently, Brown and his colleague Konstantin Batygin tracked down strong evidence for Planet 9, a large planet–about 10 times the mass of Earth–orbiting at least 200 times as far from the sun as we are. The announcement made headlines around the world. But Planet 9 is still just a beginning.

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MORE ABOUT: Nibiru, Planet 9, Pluto

The Solar System is a-Changing

By Corey S. Powell | March 31, 2016 11:14 pm
Three of the five big impacts (that we know of!) on Jupiter over the past 22 years. Comet Shoemaker-Levy 9 left a series of huge blemishes (left), but the less celebrated 2009 strike left scars of its own (middle). Two weeks ago, Gerrit Kernbauer of Austria caught another impact in the act (right). Credit: ESA/NASA/STScI; Anthony Wesley; Gerrit Kernbauer.

Three of the five impacts observed on Jupiter over the past 22 years: Comet Shoemaker-Levy 9 left a series of huge blemishes (left). The less celebrated 2009 strike created scars of its own (middle). Two weeks ago, Gerrit Kernbauer of Austria caught an impact in the act (right). Credit: ESA/NASA/STScI; Anthony Wesley; Gerrit Kernbauer.

When I was a kid and got hooked on astronomy (sometime around age 7), one of the things I deeply enjoyed about the night sky was its constancy. The human world is full of unwanted variables: Families move, friends get into fights with you, bicycles crash, birthday parties don’t turn out the way you wanted…but all you have to do is look up and you can make contact with another realm that never produces such disappointments. The stars are always in the same places. The planets slide around in the sky, but they don’t really change. Every time you see Jupiter, it is the same old reliable Jupiter.

Except that it isn’t. The closer you look at the solar system, the more you see change happening, and on all time scales. The constancy was an illusion, created by humans (not just my younger self!) watching the sky too erratically and too impatiently to see what is really going on. Jupiter is not always the same old Jupiter, as is abundantly clear from amateur video showing the planet getting whacked by a small asteroid or comet on the night of March 17. Watch other worlds and you’ll see the same thing happening. Wait longer–quite long by human standards, but very short in astronomical terms–and some really weird, extreme events unfold.

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Hunting Ghosts Across the Cosmos

By Corey S. Powell | February 29, 2016 11:56 pm
Credit: LIGO, NSF, Aurore Simonnet (SSU).

What we see versus what we believe: The bottom signal represents the vibration signal at the two LIGO gravitational wave facilities. The illustration above indicates the astrophysical interpretation of the signal–two black holes merging into one. It has taken a century to come up with the concept and technology to track down invisible gravitational waves (Credit: LIGO, NSF, Aurore Simonnet)

The recent discovery of gravitational waves by the twin LIGO detectors drove home the gaping chasm between the popular image of how astronomers explore the cosmos and the way it actually happens. In the layperson’s view — which, to be fair, aligns well with daily experience of how we find out new things — exploration is a matter of looking, seeing, and understanding. In reality, most of what astronomers do involves looking without seeing, or seeing without understanding. It involves not just working at the edge of perception, but trying to deduce what lies beyond perception.

At the risk of sounding unscientific, I’d call it cosmic ghost hunting.

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A Little Perspective on the New “9th Planet” (and the 10th, and the 11th)

By Corey S. Powell | January 22, 2016 7:15 pm
Planet 9 from Outer Space: The peculiar alignment and tilt of the 6 most distant objects in the solar system hint at the presence of an unseen massive planet orbiting far beyond Pluto. (Credit: Caltech/R. Hurt/IPAC)

Planet 9 from Outer Space: The peculiar alignment and tilt of the six most distant objects in the solar system hint at the presence of an unseen massive planet orbiting far beyond Pluto. (Credit: Caltech/R. Hurt/IPAC)

By now you’ve probably heard the announcement that astronomers Konstantin Batygin and Mike Brown think they’ve tracked down “Planet 9,” a long-rumored large world orbiting in the distant wilderness of the solar system. Even if you haven’t heard, the news may sound familiar, since a confusingly similar but completely separate report made the rounds just a month ago. (Students of history will recall that Planet X stories also circulated in 2014 and 2006, and have been a staple of the astronomy hype machine all the way back to the discovery of Ceres in 1801.)

The dreary truth is that the Batygin and Brown claim, while stronger than the ones that came before, is still soaked in uncertainty. But there’s another truth, far more exciting, that goes with it: The latest efforts to find Planet X are hugely revealing, even if these particular ones don’t hold up.

Reason #1: The competing claims starkly illustrate the difference between seeing and believing. The case for Planet 9 is much stronger than for the ones described in December, even though researchers have directly observed the earlier objects but have not seen Planet 9 at all. Better yet is reason #2: These stories keep popping up because overwhelming majority of the solar system is cloaked in darkness, and is just now coming into view. Even the latest maybe-planets turn out not to exist, it’s nearly certain that there are big, exotic things out beyond Pluto waiting to be found.

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Best of 2015: The Idiot’s Guide to Pluto

By Corey S. Powell | December 31, 2015 7:55 pm
Before and after: Pluto as seen by the New Horizons spacecraft in January and July of 2015. (Credit: NASA/JHUAPL/SwRI)

Before and after: Pluto as seen by the New Horizons spacecraft in January and July of 2015. (Credit: NASA/JHUAPL/SwRI)

What was the biggest news in astronomy this past year? The editorial board of Discover has helpfully provided an answer, one that I heartily endorse (and not only because I wrote the related story in the magazine): It was the exploration of Pluto by the New Horizons spacecraft. To appreciate just why that mission was, and still is, such a big deal, join me in a little act of mental time travel.

If you could move 6 months back in time, it would be shockingly simple to summarize what astronomers knew about Pluto–and mind you, they knew more about Pluto than about any of the other myriad frozen worlds out beyond Neptune. The Idiot’s Guide to Pluto would not include an exact diameter (nobody knew it), or structure of the atmosphere, the geology, the topography, the composition, or even Pluto’s distinctive markings (nobody knew any of those, either).

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MORE ABOUT: New Horizons, Pluto

What I’m Thankful For: The Science and Technology Edition

By Corey S. Powell | November 26, 2015 3:16 pm
Ice mountains, nitrogen glaciers, and enigmatic flows on Pluto--just one small sample of the magical images returned by the New Horizons probe this past year. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

Ice mountains, nitrogen glaciers, and enigmatic flows on Pluto–just one small sample of the inspirational images returned by the New Horizons probe this past year. (Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute)

It can feel inappropriate celebrating the exploration of the universe while the media are saturated with grim stories about warfare, terrorism, and other forms of human suffering. The issue boils down to matters of sensitivity and propriety: How can you talk about something so theoretical and remote when there are so many problems all around us? I wrote a column on this theme last year, and it feels especially timely right now as I (like so many other Americans) am stepping back to think about the things I’m thankful for.

What really struck me from that perspective was the sense of progress: The old-fashioned sense of forward motion through history, from less civilized to more, toward a better and more fulfilling lifestyle for all of humanity. It is easy to lose sight of the pattern while being barraged by news stories that give the impression we are living in the worst time ever–but by most measures, we are living in the best time ever. I’m not talking just about scientific exploration (in which 2015 witnessed historic explorations the small worlds Pluto and Ceres), but also about the overall quality of human life. Both are getting better and better, and the reasons why are intertwined.

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The Designer Behind the Greatest Fake-Mars Mission Ever

By Corey S. Powell | October 16, 2015 3:09 pm
Life on Mars: Fictional astronaut Mark Watney contemplates a very realistic landscape in The Martian. (All images credit: 20th Century Fox)

Life on Mars: Fictional astronaut Mark Watney contemplates an exceptionally realistic landscape in The Martian. (All images credit: 20th Century Fox)

With its strong showing at the box office, The Martian joins Gravity and Interstellar in the club of science-fiction movies that succeed by emphasizing the science and downplaying the anything-goes fantasy elements. But even in this rarefied company, The Martian stands apart. Unlike Interstellar, it is rooted in present-day technology and challenges. And unlike Gravity, it fully respects the physical rules of space travel; in fact, it makes them central to the plot.

The Martian comes at a pivotal time for NASA. With space imagery getting better and better–taking on an almost cinematic quality–the need for human exploration in some ways seems less obvious than ever. At the same time, the difficulty of getting any concrete answers about life on Mars (or even definitive answers about water and methane) illustrates the huge limitations of doing science using robots. Artificial intelligence and remote control are just not cutting it. By treating the human exploration of Mars with scientific respect and genuine emotion, The Martian make its case more powerfully than NASA’s slick posters and earnest Congressional testimony have managed to do.

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