Chasing Science at Dragon Con

It’s that time of year again already! I’m heading to Dragon Con in Atlanta, and as always I’ve got a packed schedule of awesome science to chase around the pop culture convention. See you there?

The Year in Science (So Far)
Friday 02:30pm in Marriott A601-A602
So far this year we’ve visited Pluto, created the previously-theoretical pentaquark particle, saw the rise of dramatic new gene manipulation techniques due to CRISPR, and more. Even Shark Week went back to being more scientific! [Read more.]

TimeTrips: Can a Stargate Do That?
Friday 04:00pm in Westin Chastain HIJ 
Time travel: how real could it be? Find out how the WHEN meets the WHERE in Stargate.

Creating Science Stories
Friday 07:00pm in Hilton 202
How do you write an article about a scientific topic? Or draw a science-themed comic? Or turn a science story into a video or podcast? Writers, artists, and producers talk about the challenges and the successes of creating science media. [Read more.]

Science of The Martian
Friday 08:30pm in Hilton 202
Andy Weir’s book is a marvel of science-driven plot. Dive deeper into chemistry, rocketry, agriculture and other science topics in the book, and learn where Weir drew his information from. This way, when you see the movie with friends, you can correct the movie in a totally not-annoying manner! [Read more.]

Carter, Frasier, & Women in Sciences!
Saturday 01:00pm in Westin Chastain HIJ
Strong female characters in StarGate inspired a generation of women toward the STEM fields.

Relativity Is Practical
Saturday 05:30pm in Hilton 202
Einstein’s theory relating mass and energy, gravity and space-time, seems esoteric. But it’s more than an abstract principle. It underlies a lot of in-the-lab research, as well as technology like GPS. [Read more.]

Solve for X Show
Sunday 10:00 pm in Hilton Grand Ballroom East
Solve for X features talented comedians, musical acts, dancers, storytellers, burlesque troupes, puppeteers,and other assorted nonsense-makers who use science as their prompt for performance. [Read more.]

Space in 2050
Monday 02:30pm in Hilton 309-310
Space people think/dream BIG! We’ll ask ‘how big’? Our experts & fans will discussion their predictions for our future in space. [Read more.]

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Atmospheric Science in Stargate: Atlantis Brain Storm

While I wrote about this a bit when the show first aired way back in the dawn of time, I recently cleaned it up and made it pretty. If you missed it the first time, you can read about it on io9

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Things I Wrote This Week

For the past two months, I’ve been writing for the Space subsite on io9. If you haven’t checked it out before, here’s some stories stories from this week that you might find interesting:

I also have a massive In Case You Missed It post covering the Space subsite for April, just in case you want to spiral down a recursive network of link-clicking. But really, I wrote some cool things last month that you might find awesome if this is the first you’ve heard of me writing for io9.

This is the last month of my trial period as an io9 Recruit. If I don’t make 300k US People in traffic for the month of May, I will no longer be writing on the io9 website. If that fills you with a gasp of denial, spread the love by sharing a story you liked on Facebook, Twitter, or whatever social media platform you desire to help me reach new readers.

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Spotting Meteoroids while Skydiving?

You’ve seen the footage of a rock falling past a skydiver. It looks like this particular object was an accidentally chute-packed rock. But, what are the chances of a skydiver eventually seeing a meteoroid?

The following is some hardcore estimating and order-of-magnitude geekery to determine how likely it is for a skydiver to see a meteorite during an average jump. Fans of xkcd and Randall Munroe’s What if? know how the next part works. For everyone else, if you ever wondered what physicists do for fun, this is how I spent my Friday night.

The game is played by making assumptions for values based on orders-of-magnitude — what’s the closest power of ten that describes the number (1 vs 10 vs 100) — then apply basic relationships to come up with a vague notion of how things interact. I strongly encourage you to play along at home — argue about my assumptions, come up with alternate methods, and please, please check my math!

How far away could you see a meteoroid?
Astronomers and optometrists measure the angular resolution of the human eye to measure how well we can distinguish objects of a particular size at a particular distance. Perfect 20/20 vision is defined as being able to identify a 1.75 mm gap from 6 meters away. Rounding to keep the numbers pretty, that works out to 0.01° angular resolution. For context, if you hold out your arm and spread your hand, your thumb is approximately 0.5°.
Angular Resolution

Let’s work with a small-but-noticeable rock, something fist- to head-sized. That’s closer to 10 cm diameter than it is to 1 cm or 1 m, so we’ll roll with that as our meteorite-size.

Rearranging the angular resolution equations to use our two known inputs, that means that a skydiver with perfect vision could spot a 10 cm meteorite anywhere within a 500 meter radius (this is much shorter than their view-distance to the horizon!). Since meteorites have a much, much faster velocity than skydivers do, matching altitude doesn’t matter since any meteorite would catch up and pass by any skydiver. Anyway, the skydiver can look not only in a 360° plane, but also up, down, and anywhere in-between.

How many people are skydiving?
So, how many people skydive? The United States Parachute Association lists 3.1 million jumps in 2012 with 0.006 deaths per thousand jumps. Assuming a constant mortality rate for 49 global skydiving deaths, that’s roughly 8 million jumps per year. For our orders-of-magnitude estimate, that’s closer to 10 million jumps per year than 1 million. Combining free-fall and gliding under a canopy, the fall duration is on order of 10 minutes per jump.


So, that’s 10 million jumps per year, at 10 minutes per jump, looking within a column with a cross-section area of πr2 ≈ 106 square meters. Run the equations out, that’s the equivalent of saying skydivers survey 1013 square meters of the planet for ten minutes per year. The entire surface of the Earth is only 5 x 1014 square meters. For ten minutes, skydivers are surveying 1013/5 x 1014 = 2% of the Earth’s surface. If skydivers were evenly distributed over the surface of the earth, skydivers survey the entire planet for ten minutes every 50 years.

How many meteoroids are falling?
This is a shockingly difficult question to answer!

Assume our 10 cm meteorite is made of solid rock (3000 kilograms per cubic meter density), it is a hefty 10 kilograms. The survey only tracked frequencies for meteorites above 1 kilogram, not above 10 kilograms (our rock), which could make this an over-estimate of flux.

A Canadian survey tracked meteorites that landed anywhere in a 1.3 million square kilometer detection area for fourteen years. From the survey every year, about 5,000 meteorites greater than 1 kg fall on the Earth, each one taking less than a minute to pass from peak skydiving-altitude to hitting the ground. Assuming the distribution is temporarily random (ignoring events like meteor showers), those 5 x 104 meteorites could fall on any of the 5 x 106 minutes in a year, or one falling every hundred minutes.

So, what are the odds of a skydiver seeing a meteoroid?
In our idealized, simplified world: what are the chances that the meteorite will come down within the ten minutes and 2% of land-surface area where a skydiver is looking? If meteorites are randomly distributed across the planet, the chances that a meteorite will strike somewhere a skydiver is looking is 0.2%, or a near-certainty in a 5 centuries of skydiving.

Swarms of Skydivers

Variations on the Theme
What happens if some of the starting assumptions are off?

  • Skydivers might not notice something at the edge of their visual acuity. Running through the same math at a blindingly-obvious 1° angular resolution, twice the apparent size of the moon, drops visibility to rocks within a 5-meter radius, or 102 square meters. This drops the chances considerably, to 0.00002%, or 2% over ten millennia of skydiving.
  • Skydivers aren’t looking everywhere at all times. You could re-run this math limiting the field-of-view to a 120° cone instead of a full sphere of vision. This drops the chances by an order of magnitude to 0.02%.
  • Skydivers aren’t evenly geographically distributed over the entire planet. Over a third of jumps are over the United States, and I’m willing to guess none of them are over the North Pole. But, that doesn’t really matter, since it means skydivers less likely (not at all likely) to spot a meteorite that happens to come down over the Arctic Ocean, but far more likely to see any that come down in skydiving hot-spots like California, Florida, New Zealand, several tropical islands, Spain, Italy, Nepal, or particular locations in Africa.
  • Meteorite frequency rates by size are not well-constrained. Our ability to detect meteorites is increasing gloriously quickly, and I look forward to better estimates in the future. For now, every order of magnitude the flux rate is overestimated, drop the chances by the same amount: If 10 kilogram meteorites fall only 500 times a year, the chances of a skydiver seeing one is 0.02%.

But even with all these assumptions, when it comes to asking “What are the odds of a skydiver seeing a passing meteorite mid-jump?” the answer is, “Better than winning the lottery!”

We’re starting to see all sorts of footage of these rare, amazing events. While the event that triggered this question probably isn’t a meteoroid, it’s also a reminder that “incredibly improbable” is actually really common when you start thinking about the billions of people on this planet going about their lives for year after year after year.

A variation of this post is going to go live on io9 at 3pm EDT. If you have big comments for me to correct before then, please let me know! If you loved it, please hold off and share that link instead, as my work performance is evaluated by traffic.

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Dear Kepler, I love you.

Kepler is the plucky little spacecraft that taught us we aren’t alone in the universe, and that planets are everywhere. It captured the imagination of farmers, citizen-scientists, and astronomers alike. This is the story of Kepler, in celebration of turning the theories of planetary science upside-down.

Since the satellite launched in 2009, NASA’s Kepler telescope has discovered 961 confirmed exoplanets, with 3,845 candidates awaiting verification. After five years of new observations, new worlds, and new theories, Kepler’s field of view has been realigned to compensate for equipment failures. Crippled, but functional, this year marks the start of a new mission of discovery.
To mark Kepler’s 5th anniversary and the transition from its original mission to the new secondary mission, we’re bringing you a round-up of everything Kepler. This is the story of a half -decade of planetary science theories demolished, revised, remodeled and demolished again, and a telescope that just won’t give up on making new discoveries.

Dr. Alexander Wolszczan identified the first exoplanet in 1994, when he found planets blocking the radio pulses of their home star, an inhospitable pulsar. The next exoplanets were discovered using radial velocity, the pull of a massive planet on its star. By the end of the century, several dozen worlds had been found. Then in 2006, the French launched CoRoT, the first dedicated planet-hunter. CoRoT successfully located a few dozen exoplanets and confirmed others. By 2009, CoRoT was sitting pretty on a respectable stack of carefully-characterized planets outside our solar system. And then came Kepler…

2009: Launch, First Light, and learning to hunt for planets

A night launch at Cape Canaveral on March 6, 2009 sent Kepler into orbit to hunt for exoplanets. After orbital adjustments, camera tests, and settling down into just the right field of view, Kepler’s First Light of the Cygnus-Lyra region in April was captured without a hitch.
Kepler was positioned to look at exactly the same patch of sky all the time. It wouldn’t capture beautiful photographs like Hubble, but instead collect extremely detailed light curves of the same stars, hour after hour, day after day, for year after year. Scientists were hunting for the telltale dip in brightness of a planet transiting its star. As a planet crosses in front of its star at regular intervals, the star’s brightness is reduced by a tiny fraction. Any star with periodic dimming is tagged as a candidate system. Follow-up observations weed out false positives before scientists confirm discovery of a new exoplanet.

Astronomers predicted that Kepler would find about 50 Earth-sized planets in one-year orbits, and maybe 185 slightly-larger-than Earth-sized planets. The expectations were similar for giant planets, originally anticipating the discovery of 135 inner-orbit giants, and 30 outer-orbit planets. The hunt was on: find 400 exoplanets before funding ran out in November 2012.

2010: The Year of Hot Jupiters
The first five finds unique to Kepler were announced in January 2010. All five were gas giants in close orbits, promptly earning the moniker “hot Jupiters.” These were disappointing worlds for scifi fodder (aside from Cloud City, we have a distinct fondness for exoplanets with a surface we can see), but more importantly, they demolished our exiting theories about planetary formation. The established model, “heavy stuff at the center, light stuff at the edges” that our system exhibits so cleanly with its inner terrestrial planets and outer gas planets didn’t make sense in a universe that had to include “hot Jupiters”. Suddenly, we had a handful of huge, low-density gas giants nestled in against their parent stars, in orbits that made no sense in existing theory.

Desperate to restore peace and order to planetary science, theories immediately started popping up to declare hot Jupiters were a momentary abnormality, quickly destroyed by their suns or pushed into more reasonable orbits. Their parent stars consume them in a feeding frenzy of hydrogen gas. Stellar winds blow the gas right off them, leaving denuded hard cores in orbit. The intense heat and gravity of such a close orbit would tear them apart and burn them to a crisp, possibly at the same time. Whatever the mechanics, hot Jupiters must die.

Within months, a system was observed that exhibited rhythmic variation in its periodic dimming. Clever brains thought clever thoughts, and tried modeling what sort of timing variations a multi-planet system would produce. They paired observed variations with modeled planetary transits, and the first multi-planet system, two planets orbiting a single star, was confirmed.

2011: From rocky planets to an explosion of candidates
The first discovery of the new year was a more conventional rocky planet but this one came with a twist too. It was even closer to its star than Mercury is to ours, and the modeled surface temperatures are comically high. Even the most enthusiastic astrobiologist wasn’t going to theorize about life on a planet with surface temperatures so hot even rock was charred.

A few candidates were eliminated by astronomers as exoplanets, but embraced by astrophysicists for giving insight into stellar formation. One of the false-positives was a triplet-system of three stars. A massive red giant and two tiny red dwarfs twirling around each other in a complex dance cycle of eclipses, producing entrancing brightness variations. Even Kepler’s rejected not-really-planets made for spectacular astronomical discoveries.

By May 2011, the research team was beginning to go into shock. Kepler had racked up a list of more than 1,200 candidate planets far exceeding the initial 400 projected discoveries. Multi-planet systems were turning out to be far more common than anyone thought.

Francois Fressin of the Harvard-Smithsonian Center for Astrophysics called a time-out to introduce a new processing technique. Blender, a light-curve computer simulator, was applied to candidate systems to try to explain away the brightness variations as the interaction of multiple stars. Only if no combination of stars worked did he invoke exoplanets. He tested the idea with the Kepler-10 multi-planet family, recruiting NASA’s Spitzer Space Telescope to stare at the system. When his simulated light curves matched both Kepler’s visible light and Spitzer’s infrared observations, the multi-planet system was confirmed and Blender joined the arsenal of planet-hunting techniques.

But the relentless Kepler was just getting warmed up. Next, Kepler spied an exoplanet circling a single star of a binary system and then a planet of perpetual night, a planet whose surface absorbs 99% of all light that hits it. “TrES-2b is considerably less reflective than black acrylic paint, so it’s truly an alien world,” astronomer David Kipping explained in the press release.

As more data poured in, researchers experimented with validating instead of verifying candidates. In verification, confirming an exoplanet meant gathering a secondary set of observations to confirm its existence. With validation, astronomers construct a theoretical model of the planetary system, then confirming that the observed dynamics match the model. The technique was first tested on a system featuring multiple gas giants squeezed into a ridiculously tiny orbital radius, the cosmic equivalent of a clown-car bursting with fake noses and over-sized shoes. Once again, experiment matched theory, and another tool joined the collection of planet-hunting techniques.

The itch to do something really clever was scratched by the appearance of Kepler-19, in the constellation Lyra. This time Kepler had found a planet where the orbital dynamics were off. Very precisely 5 minutes off, give then take, each orbit. Off, in just the same manner that it would be off if another planet was yanking on it. Just like that, Kepler had discovered the Invisible World. Finding an invisible planet is a slick move. Without ever directly seeing the planet transit its star, another exoplanet was added to the list based on its invisible gravitational tug on the other planet in its system

The following month, Kepler started spotting Earth-sized planets. The first one was a bit bigger (1.6 x Earth radius), a bit heavier (<10 x Earth mass), and a whole lot closer to its slightly bigger sun (0.04 x average Earth-Sun orbital distance). Then it spotted a multi-planet system that had a rocky planet even smaller than Earth. It looked like that rocky planet might even be tectonically active, eliciting the appearance of sprouting volcanoes in the artistic representations. By the time Kepler’s first annual report rolled around, everyone involved was a bit googly-eyed. Planets had turned out to be shockingly easy to find but their behavior was not at all what we expected.

2012: Circumbinary Planet Systems: weird, weirder, weirdest
By January 2012, the science team was compelled to invent new vocabulary — circumbinary planet systems — to describe systems where planets orbited more than one star. Circumbinary systems opened up a whole new realm of comparative planetology, with such strange possibilities that you can almost hear the giddy excitement even though the sterile language of a press release:
“These planets can have really crazy climates that no other type of planet could have,” said Dr. Jerome Orosz, a co-author from San Diego State University. “It would be like cycling through all four seasons many times per year, with huge temperature changes.”
[co-author Dr. William] Welsh adds, “The effects of these climate swings on the atmospheric dynamics, and ultimately on the evolution of life on habitable circumbinary planets, is a fascinating topic that we are just beginning to explore.”

Before long, Kepler challenged its press officers to harness their inner cuteness-addict to describe what even the press release acknowledged was “the cutest planet system yet,” a tiny trio of planets orbiting a wee little red dwarf. Each planet was smaller than Earth, one was even bordering on Mars-sized small. The system offered a poetic analogy: set side-by-side, Jupiter and its moons and Kepler-961 and its planets were roughly the same sizes and distances apart. Kepler-961 was the Jupiter that succeeded as a star; its planets, the Galilean moons promoted. Of course, the artist’s conception for all this adorableness took advantage of the red star-glow to coat everything in pale pink light.

The weird systems kept piling up. A pair of planets in separate orbits had close approaches every three months, coming within five times the Earth-Moon distance in some version of Upside-Down that somehow stumbled into reality. Another circumbinary system, then a multi-planet circumbinary system. Just when we started to feel like maybe our solar system was the anomaly by being so normal compared to the exoplanetary insanity reaching out in all directions, Kepler found our solar-system twin. Finally, here was a system aligned just like ours. Sure, the distribution of rocky and gaseous planets within our system might still be a fluke, but at least we weren’t alone in our rationality.

Citizen-scientists started combing through the Kepler data as part of the Planet Hunter project. In what was becoming par for the course, their first confirmed planet was extraordinary. The amateur Planet Hunters found the first ever quad circumbinary system: a planet circling not one, not two, but four stars! In the accompanying press release, astronomer Meg Schwamb acknowledges, “The discovery of these systems is forcing us to go back to the drawing board to understand how such planets can assemble and evolve in these dynamically challenging environments.”

It’s a beautifully understated acceptance of the iterative process of scientific discovery. No bafflement. No confused outrage. No irrationally clinging to planetary formation theories that look ever more naively simplistic. It’s a simple statement of, “Whoops, guess we’re going to need to come up with a new idea for what’s going on!” that encompasses everything I love about science. Thankfully, soon after admitting that we had no idea what was going on anymore, Kepler’s budget was extended for several more years of planet-hunting. With a bit of luck, at some point we’d hit a saturation point of accepting incredible, undreamed-of planetary arrangements, and start putting the theoretical pieces back together again

In July 2012, the first hiccup to the mission hit: one of four gyroscope-like reaction wheels used to stabilize and aim Kepler crapped out. Like most spacecraft, Kepler was built with redundancy in mind, so the other three were sufficient to keep the mission running smoothly. Engineers fruitlessly brainstormed ways to restore the malfunctioning reaction wheel while Kepler resumed hunting for planets. Meanwhile, geeks everywhere lost an afternoon playing with an interactive adaptation of the XKCD graphic of all 786 confirmed planets, and then another one watching the “What if…” video of all 2,299 exoplanet candidates orbiting a single star.

By October 2012, second-generation papers were coming out. These ones took the observations beyond, “Look, it’s a planet!” and dove into the data to see what else could be teased out. The detailed data from observing Kepler-1b for years was analyses for ellipsoidal variations and Doppler beaming, or how Kepler-1b moved and how brightness varied with planetary transits. The combined analysis results in mass ratios between the planet and its star. The radius of the star can be calculated from astroseismology, changes in brightness from internal waves within the star. This drops the number of unknowns to the point that relative planet size is used to calculate planetary radius. Read that again: by looking at infinitesimally small changes in brightness in a star, we can calculate the radius of the planets that orbit it.

But the papers don’t end with orbital dynamics. Daily rotation of the planet led to thinking about diurnal temperature differences. Run temperature gradients as inputs into atmospheric models, and suddenly a whole new field of exometerology emerged, looking at potential weather patterns on alien worlds. That is a seriously impressive amount of information to pull out of simple brightness curve, even when the data is extraordinarily detailed and covers multiple years.

2013: Even more candidates, telescope-tragedy, and rebirth into Second Light
During the annual discovery-roundup in January 2013, the theme was “Planets, planets, everywhere!” In every patch of sky covered by Kepler’s field of view, exoplanets of all sizes had been observed. We were finally pounding it into our own thick heads: planets aren’t rare. The odds of finding an Earth-like planet were skyrocketing due to the sheer number of planets in the universe. The press statement for the preceding year concludes:
“The analysis of increasingly longer time periods of Kepler data uncovers smaller planets in longer period orbits– orbital periods similar to Earth’s,” said Steve Howell, Kepler mission project scientist at Ames. “It is no longer a question of will we find a true Earth analogue, but a question of when.”

Statistical analysis that February reinforced the point: Earth-sized planets in the habitable zone of cool stars are overwhelmingly common, and we’ve probably got one within 68 light-years from Earth. From the press release:
“We thought we would have to search vast distances to find an Earth-like planet. Now we realize another Earth is probably in our own backyard, waiting to be spotted,” said Harvard astronomer and lead author Courtney Dressing

Even better, those planets could be circling long-lived, cool red dwarf stars. That opens up the possibility that life around one of these alien stars could have a several-billion year head start on our puny 4.6 billion year history. So all that scifi with ultra-evolved alien species, the ones that consider Earthlings the upstart teenagers? Not necessarily far off the mark.

Exoplanets keep getting smaller every year.
As the length of time we have been observing a system keeps getting longer and longer and longer, the planets we can detect in that system keep getting smaller and smaller and smaller. Soon, Kepler would need to deal with the Pluto debate on its discoveries. At what point would a candidate exoplanet really be a dwarf-exoplanet? (Or is that an exo-dwarf planet?) The Pluto-killers at the International Astronomical Union (IAU) place the boundary between planet and dwarf planet at something that has enough mass to be round, and able to clear its orbit of any other planetary bodies. At a whisper bigger than our moon, Kepler-37b probably clears out its orbit, so it’s a planet. Or, at least, it is for now until kill-joys at IAU scatter some asteroids in its path to make it prove it can clear as effectively as the big kids.

Not even 3.5 years after the phrase “hot Jupiter” was coined, the theories of their imminent and ongoing doom were contradicted. In the evocatively-titled Stars Don’t Eat Their Young Migrating Planets, astrophysicists conclude that stars don’t cannibalize hot Jupiters as a matter of course. Instead, tidal forces circularize the planet’s orbit. The stable radius varies by planetary mass, each planet drifting outwards until attaining a more reasonable distance from their star.
In May 2013, tragedy hit the telescope when a second reaction wheel died. By August, engineers resigned themselves to being unable to restore Kepler to its former fully-functioning glory. In October, the shutdown downed the Kepler website and all non-essential functions. For a telescope tumbling alone in space, the future couldn’t look much more grim.

Despite the echoing silence from Kepler, ever more discoveries of strange new worlds were being extracted from the accumulated data. A spitfire world races through an entire year’s orbit in just 8.5 hours. Another world wobbles within its orbit as if its had a few too many drinks before stumbling home. One system has an ordinary planetary plane, except for one planet pried into a suspiciously high angle. A Goldilocks system is uncovered, where a trio of Earth-like planets are all within the habitable zone just right for the development of life.

Even the false positives were advancing science, with stellar astrophysicists developing a new technique to link brightness variations to the surface gravity of stars.

By the time the shutdown ended, those very clever brains had come up with a very clever solution to the tragically tumbling telescope. With only two reaction wheels, they couldn’t keep Kepler stabled and pointed at its original star field, so they stopped trying. Instead, they borrowed the sun to act as a third stabilizer. They reoriented Kepler so that solar pressure was balanced across the spacecraft’s surface. This marked the end of Kepler’s primary mission, and the long-term observation of the Cygnus-Lyra star field, but the beginning of it’s new mission: (K2) to observe the Sagittarius star field. Kepler was stabilized and captured its Second Light. Now, it was up to the team to practice maintaining the delicate balance of unstable equilibrium for hours, days, and weeks at a time.

2014: Exoplanet, Confirmed!
The New Year brought unwelcome news that along with reduced mobility, Kepler was also slowly going blind. The first of 25 science modules had been lost years before; now a second died to a random system failure. Undeterred, Kepler soldiered on through the testing phases for K2 with a few more blind spots but still a functional scientific machine.

The real news for 2014, the news that brought Kepler into the headlines and spawned endless jokes, is that a new data processing technique moved 715 planets from “candidates” to “confirmed” overnight. I’m surprisingly grateful NASA didn’t pitch the press release as, “Find 715 planets with this one weird trick!” The “weird trick” is verification by multiplicity. If one false positive is rare, then several simultaneous false positives in the same system is downright implausible.

Imagine a system with five candidates around a single star. Those candidates can be either five real exoplanets, or five false positive stars. In this NASA animation, watch the planets stay in neat, orderly, stable orbits, and watch the stars spiral, swirl and shoot off into chaos. Every candidate confirmed with verification by multiplicity must be in a multi-planet system: all 715 planets are in just 305 systems.

This batch-verification brings total discoveries up to 961 confirmed exoplanets, more than double the original expectation of 400. All data collected in the original mission before the reaction wheel breakdown contains an additional 3,845 exoplanet candidates awaiting verification. While designed as a planet-hunter, Kepler also served stellar astrophysicists by identifying 2,165 eclipsing binary systems. Kepler produced a unique, high-quality dataset for a single field of view covering multiple years: it’s a dataset of incalculable scientific value. Already, researchers are contemplating how to mine the data for evidence of moons outside our solar system.

The sheer number and variety of planetary systems uncovered has taken planetary science from cocky confidence through uncomfortable confusion and back out into awe-struck curiosity. We started this hunt with a perfect theory that explained our own solar system, only to watch it be shredded by the first batch of planets we uncovered. Each time we tried to patch the theory back up, another exoplanet would tear out an exception. Finally, we were left staring at the data, acknowledging the depths of what we don’t know, and starting to put the pieces together in a whole new order.
In just five years, Kepler has exceeded all expectations. It delivered a steady stream of new types of planets, and planetary systems. We’ve gone from a handful of verified exoplanets, to a diversity of worlds that defies imagination. In the ongoing tradition of our robotic explorers doing far more than we anticipate of them, at five years and partially crippled, Kepler is just settling into starting a whole new mission.

Here’s to you, Kepler. You’re a planet-hunting beast that has transformed the very foundations of how we think about planets, moons, and alien stars. You made astounding contributions to science, the depths of which we will not fully process for years to come. I salute you, and wish you the best of luck in your new quest.

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I love the Kerbal Space Program. Here’s some of my favourite screenshots from the past few months of playtime.

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I’m over on as a writer and quasi-editor (highlighting quality space-related content from other locations in the Gawker media universe), commenting on astronomy news and teaching space science with a health dose of irreverence and snark. Go on, check it out.

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Day of the Doctor

With the Doctor Who 50th anniversary less than a day away, I’ve got a piece up on Physics Today about the astronomy and cosmology in Doctor Who.

Thank you to everyone who helped with the article, particular Green College fellows Josh Scurll, Amy Smith, and Andrew MacDonald for long conversations about alien biology, and to Earth & Ocean Sciences professor Stuart Sutherland for chatting with me about dinosaurs, microfossils, and catastrophic impacts.

Related Reading:
‘Doctor Who’ Science Fact: Five Whovian Things That Exist In Real Life
Tests of Big Bang: The Light Elements
5 Doctor Who Concepts That Are Scientifically Possible And 5 That Are Impossible
NASA Lunar Scientists Produce New Model for Earth/Moon Formation
Origin of life experiments revisited
Fusion in stars
The dangers of solar storms: That which gives power can also take it away
Fried Planets
Phil Plait’s Death from the Skies

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2013 Dragon Con schedule — asteroids and disasters and scifi, oh my!

Officially, I’ll be visiting the Space, Science, Stargate, Science Fiction Literature, Apocalypse Rising and American Science Fiction and Fantasy Media.

As always, Dragon Con schedules are subject to change with very little notice, so use the Dragon Con mobile app (find me under Presenters > Mika McKinnon) or the Daily Dragon to stay up-to-date on scheduling changes.

Friday, August 30th

5:30pm in Hilton 309-310, Space track
Incoming! There’s an Asteroid with Earth’s Name on it! Russia’s recent Tunguska-like event has made the danger of an asteroid strike very real, even to Congress. Panel with Phil Plait.

This panel will be on my first love in science, the puppy-eyes of disaster that lead me through an undergraduate degree. We’ll cover current events, upcoming events, sorting fact from fiction out of the regular doomsday-predicting news reports, give you ways you can help save the planet from utter destruction, and answer any questions you’ve got.

Saturday, August 31st

1:00pm in Westin International FGH, Stargate Multiverse track
The Master of Disaster returns! Boom, crash, BANG! Welcome Mika back to the controlled chaos that is the SGMT, and learn all about the science behind the Stargate. Solo storytelling and Q&A.

Stargate: Atlantis and Stargate: Universe introduced me to working on set, a dream-job that required suppressing my fangirl squeals of delight, and SMGT introduced me to Dragon Con. This is my most relaxed event for the weekend, and the perfect place for questions about the science or behind-the-scenes storytelling.

4:00pm in Westin International FGH, Stargate Multiverse track
Dr. Geek’s Laboratory Live! Podcast Dr. Geek has been called this generation’s Mr. Wizard. See why in this live podcast. Podcast with Ken Spivey and Dr. Scot Viguie

4:00pm in Marriott M301-302, American Science Fiction and Fantasy Media
Continuum: Making the Future Reeling through its first and second seasons, this Syfy show is a real thinking person’s SF. Is it formula or fresh insight?

I have a soft spot for dystopian futures, tangled plots, and plausible physics, and now I get to share that with you.

8:30pm in Hilton 202, Science track
DOOM! The Planet is Trying to Kill Me! An introduction to the mechanics of earthquakes, tsunami, hurricanes, and other catastrophes. Solo presentation and Q&A.

After my first love of doomsday impact events, I found my way to my True Love of natural catastrophes that can utterly devastate individual lives and societies without destroying the planet, and the source of my Master of Disasters. The best form of risk reduction is education, so come by for a primer on every natural disaster I can squeeze in while still leaving time for questions.

Sunday, September 1st

1:00pm in Westin Vinings 1-2, Apocalypse Rising track
Ten Years Later You had what it takes to survive the end of the world, but do you have what it takes to rebuild it? Panel with David Harmer and Gail Z. Martin.

Anyone who makes it to Day 3 of Dragon Con clearly has the stamina to make it through the first week, month, and year of a major apocalypse. Come on by for the challenges and skills needed a decade out. An interesting and strangely practical panel that I find leaves me itching to pick up a new DIY hobby.

4:00pm in Hilton 202, Science track
DIY Science: Get Your Science on! The new field of Citizen Science Projects to get you started, how they work, and what you learn by participating. Panel with Dr. Pamela L. Gay.

Aside from my general enthusiasm for hacker and maker spaces, DIY submarine exploration and high schoolers saving us from asteroid impact annihilation, I’ll also be cooing enthusiastically about distributed disaster reporting projects like Did you feel it?

8:30pm in Hyatt Embassy A-B, Science Fiction Literature track
Teaching Science Fiction When science fiction is taught in schools, what should or should not be included? Are there any specific concerns teachers should keep in mind? Panel with Farah Jane Mendlesohn and Jody Lynn Nye.

I am a strong advocate for using literature as a way to access science fiction, both to re-energize textbook-weary science and engineering students and to reach out to science-shy humanities students. I can almost promise I’ll give a quick lesson on parasite and predator mass ratios as mis-applied in Alien, and an ode to the fluid & orbital dynamics in Mission of Gravity.

Monday, September 2nd

…nothing scheduled?! Oh my!

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Elsewhere on the internet… Elysium

Science review of Elysium over on suggests that the technology is plausible.

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