What Is This Mystery Object in an Astronaut’s Photo?
And sometimes we get a mystery. I have one of those for you today.
This started when I got an email from Nahum Mendez Chazarra, who had been going through pictures taken by astronauts from the ISS. In a batch taken on July 15, 2014 around 11:57 UTC, he found three in a row that showed a curious thing. Here’s one of them:
Spectacular! The ISS was south of Australia at the time, so the green glow is the aurora australis, the southern lights. The ISS solar panels stick into the shot from the upper right (seen nearly edge on), and the Earth dominates below.
But look to the Earth’s limb, just below and to the right of the brightest part of the aurora, and just above the solar panel. See that streak? It’s clearly some sort of moving object.
It’s in the two pictures taken just before this one as well. I added them together and zoomed in on the object so you can see it better:
Some things to note: The first picture had an exposure time of 0.2 seconds, the second one was 0.4 s, and the third 0.8. Measuring the length of the streak, it looks like the object is moving at a constant apparent velocity (the last streak is 4x longer than the first, and twice as long as the second, as you’d expect from the exposure times).
Here's an animation I made to show the motion more obviously:
Chazarra suspected it was a meteor, burning up in the atmosphere below the ISS. At first I disagreed, thinking it might be a satellite. But then I wondered… so I sent a note to my friend Jonathan McDowell, who is an expert on things in orbit. He noted it was consistent with a satellite or a meteor, and added it could also be a small bit of debris much closer to the station; for example, a piece of ice just a few dozen meters away.
Arg! How to distinguish between these?
Well, one way would be to look at pictures taken just before and just after this set. So I did, and found that the object is not in pictures taken just three seconds earlier, nor is it in the next set taken three seconds later!
If it were a satellite or a piece of debris moving at a constant speed, then I’d expect it to be in at least the first picture taken after this set of three, down in the lower right. I looked carefully; it’s not there. That makes a satellite or piece of debris less likely (though still more likely than some alternatives). Also, note how in the picture above it crosses over the face of the Earth; that means it must be in a lower orbit than ISS. If it were up higher then it could never be seen against the Earth like that. The ISS is at a height of about 415 km (260 miles), which is pretty low. There aren’t many satellites orbiting appreciably lower than that height. This doesn’t preclude it being a satellite, but a priori it makes it less likely.
That leaves meteor. That does fit most of what we see; it appears suddenly, disappears just as suddenly, and moves at a relatively constant rate. If it were small bit of rock it wouldn’t necessarily flare up and get hugely brighter, which has been seen before when a Perseid meteor burned up as seen from ISS:
The object does seem to be brighter in the longer exposure, which is interesting. Since it’s moving, each pixel should be about a constant brightness; a longer exposure just means the streak is longer, not brighter. If it’s actually brighter per pixel, that means the object itself was getting brighter, as a meteor would. However, a longer exposure also means the Earth and other stationary background objects get brighter, and their light would add digitally to the object’s, making it look brighter even if it isn’t.
In the end, I’m leaning toward this being a meteor, but I cannot be positive. It’s still something of a mystery, as promised.
So, BABloggees: What do you think? What did I miss? Is there more (or less) here than meets the eye? I think that throwing this out to the Hive Mind might bring some insight to the puzzle.
What is this thing?
Rocketcam Video of the SpaceX Falcon Booster Splashing Down in the Atlantic
The private company SpaceX has been making amazing strides in making it easier and cheaper to access space. Besides three missions to resupply the space station under its belt, it’s also looking for ways to reuse the first stage booster of the Falcon 9 rocket.
Engineers there have been testing hardware and software to do a soft vertical landing of the booster after it’s used to loft a payload into orbit. Their last vertical take off and landing test earlier this year was a success, reaching a height of a kilometer before safely touching back down.
They did a flight test of this in April, but the video was unfortunately corrupted. But a second attempt, during a launch on July 14, 2014, went better. The mission was to put a collection of global communication satellites in orbit, but there was also a test of the soft landing system as well. The test went pretty much according to plan, although the impact of the booster into the ocean damaged the hull. They’ve released a pretty cool video of the test:
The re-entry engine burn, landing burn, landing leg deployment, and soft landing went well, and the booster even tipped over into its “water saving state” correctly. Even if the hull ruptured, they are saying they got enough information to move forward on this technology to make it work.
Another such test will happen in a launch planned for September (flight 13 for the F9), but it’s expected to have “a low probability of success” since they’re still working on the tech. However, the next two flights after that will be attempts to land the booster on land. If that works, it’ll be nothing short of spectacular, and the video will be very, very cool. Stay Tuned.
Tip o’ the nose cone to my pal Alan Boyle.
My 2014 Comic-Con Schedule
Starting tomorrow is the madhouse that is San Diego Comic-Con, and I’ll be there. I’m moderating two panels and participating in a third, and it’s always way more fun than I remember it being (and I remember it being a lot of fun). Just in case any BABloggees are going, here’s my schedule for your edification:
Thursday, July 24 at 12:45 p.m.: Behind the Scenes of Sci Fi in Movies and on TV (Room 6DE)
I’m moderating this panel of four incredible people: Nicky Perlman (co-writer of Guardians of the Galaxy), Amy Berg (Caper), Jane Espenson (80 bazillion things like Firefly, Once Upon a Time, and Husbands), and Gale Anne Hurd (producer of things like, oh, say, Terminator, T2, Alien, Aliens, and Walking Dead). We’ll be talking about new ways we consume media, and what it’ll mean for the people who create it.
Friday, July 25 at 6 p.m: The Science of Science Fiction (Room 7AB)
This is always a great panel, featuring people who write and consult on TV and movies, where we discuss how science is treated (or mistreated) in sci fi. Trust me, if you’re at SDCC you want to attend.
Saturday, July 26 at 1:30 p.m.: Marvel's Avengers S.T.A.T.I.O.N. Superhero Science Analysis (Room 5AB)
I’m really excited about this one: I’m moderating a panel of several of the science advisers for the Marvel superhero movies, and we’ll be discussing the science behind the Avengers. We’re going to be running it in a very fun way, but before his death ex-Director Fury has made it very clear to me I’m not at liberty to disclose how … but if you read the description you’ll get a hint. Still, in general I’m not inclined to argue with Fury. Even posthumously.
As for the con itself, I’ll be running around meeting up with friends, attending posh parties, hobnobing with celebrities, y’know, the usual. I’ll be at w00tstock for sure (not onstage, but watching) and I hope to make it to the Geek and Sundry lounge, as well as Nerd HQ.
And, of course, wandering the exhibit hall buying stuff I don’t need but desperately want. If you see me, come say hi!
The Longest Year
I don’t usually write about newly discovered record-breaking objects found by astronomers, because in general it’s not long before that record falls. But in this case, I’ll make an exception for Kepler-421b. It has the longest year—that is, it has the longest orbital period around its star—for any exoplanet yet seen crossing in front of its star.*
That by itself is enough to make this an interesting object, but even cooler (literally) is where that puts this planet: Far enough from its star that it may have formed in a different way from the other planets we’ve detected around other stars. It may very well be an ice giant, like Uranus or Neptune, and not a gas giant or rocky planet.
First, let’s go through the basics: The host star is Kepler-421, a star much like the Sun but a bit smaller and cooler. It’s located about 1,000 light years away, which is a fair ways (the Milky Way galaxy is 100,000 light years across). From Earth, that makes the star pretty faint.
The planet, Kepler-421b, was discovered by the Kepler observatory, a space-based telescope that has found so many of the recently-discovered exoplanets. It uses the transit method to find planets; if we see the planet’s orbit around its star edge-on then every time the planet passes between us and the star it blocks a bit of the star’s light. It’s tricky; for example Kepler-421b only blocks about 0.3 percent of the star’s light. But with modern detectors, that sort of dip in light is detectable.
Generally speaking, you need three transits to be sure you’ve got something. If you see just one it could be a starspot, or some other nonplanetary object interfering with your observations. A second transit tells you the orbital period (the year) of the planet, but it could still be a coincidental starspot. If you get a third transit at the right time interval after the second, then you can be more confident.
For Kepler-421b, the astronomers only saw two transits, which made me suspicious, but after reading their paper I’m more inclined to think they got it. The shape of the “light curve” and the incredible match between the two transits make it very likely they did find a planet. For the rest of this article I’ll just assume it exists, but remember that it has yet to be confirmed independently.
Kepler-421b is about four times the diameter of Earth (judging from how much of the starlight it blocked), and has a year that’s 704 Earth days long. That’s amazing; most exoplanets found have much shorter periods, like days or weeks. That orbit puts it about 180 million kilometers (110 million miles) out from the star. Since the star is cooler than the Sun, the planet actually receives about one-fourth the light from its star as Earth does from the Sun. That’s even less than Mars gets, so the planet is pretty chilly.
And that brings us to the second cool thing about this planet. Planets form from broad disks of material orbiting the star when it’s young. Close in it's hot (duh) so you don’t get much gas or ice. The material in the disk is mostly metal and rock. Farther out there’s still metal and rock, but water is in the form of ice (this distance is called the “snow line,” a term I like), and there’s lots of it. Giant planets that form at least that far out have a lot more ice than ones farther in, and we call them ice giants. To be clear, these aren’t giant ice balls; they look a lot like gas giants but have more ice in them as opposed to rock and denser stuff.
In our solar system, Uranus and Neptune are ice giants. Given Kepler-421b’s location, it should be one as well. If we assume it’s about as dense as Uranus, it has 16 times the mass of the Earth. That will likely give it a thick atmosphere (and it’s very cold, remember) so it’s not Earth-like at all.
But it’s the first ice giant seen orbiting another star. We’ve seen other planets with similar masses and sizes, but they orbit closer in, and are likely gas giants. Ice giants may very well be pretty common among exoplanets, but they’re pretty hard to detect. For one, the long period means you have to wait a long time to confirm them. Also, the bigger the orbit is, the less likely it is we’ll get a transit — a planet close in to its star can be seen to transit from a wide range of viewing angles, but a more distant planet needs a more tightly constrained viewing geometry (the orbit has to be more precisely edge-on) for us to spot it.
Finding Kepler-421b means that astronomers may be able to start finding more. Seeing one planet might be an anomaly, but if you find 20 more like it you can start categorizing them. This means they can use physics and models to understand better how planets form, especially that far from their parent star. We’re still figuring that out for our own solar system, so having other examples with which to compare and contrast is very helpful.
And so that’s why I’m willing to write about a record-breaker, even if that record is soon broken. As usual in astronomy, I hope it is! That turns this planet from a weirdo into the first member of its class, and that means we get to learn stuff. And astronomers love learning stuff.
*Correction, July 23, 2014: This article originally stated that Kepler-421b has the longest year of any known exoplanet. It has the longest year of any exoplanet found by the transit method.
Another Mind-Crushing Illusion: Straight or Curved Motion?
From the twisted mind of brusspup comes another brain-hurting illusion. This one is really, really convincing, so tell me: When you look at this video, you’re seeing a circle of eight dots rotating as it spins around inside a bigger circle, right?
No, you’re not. As brusspup shows, each individual white dot is moving in a straight line! The trick here is two-fold: One is that the dots aren’t moving at constant velocity (you can see that in the video at the 0:44 mark), and that combined their motion mimics what we’d see if a smaller circle is rolling around inside a big one.
Try as I may, when I look at this video I can’t make my brain see the dots moving linearly; it looks like a circle rolling. If I focus on one of the dots I can see it moving back and forth along a line, but the others still look like the rim of a circle rolling around. For most illusions there’s a moment when your brain can see what’s going on and the illusion shatters, but not with this one. It’s maddening.
When I was a kid, Spirograph was a very popular “game.” It wasn’t really a game, but a set of clear plastic disks with gear teeth around them (or rings with teeth on the inside). They had holes in them; you’d pin a ring down on a piece of paper, then take another disk, place it inside the ring, put your pencil tip in a hole, and roll the inner disk around inside the outer ring. The results were really lovely and graceful interlocking and overlapping curves. If you’re a lot younger than me and missed this craze, here’s a video that’ll help you picture it:
Man, I miss Spirograph. It was so much fun*! And this dots illusion is related. In Spirograph, when you’d use your pencil to roll around the inner disk, the motion you made was very similar to what you’re seeing in the illusion; it was more of a back-and-forth motion than an around-and-around one. It’s difficult to explain without math, which I find funny; I have a visceral feeling for it because of all those hours I spent playing with a Spirograph when I was little.
If you want the math, then here you go: The shapes made this way (tracing the motion of a point on a circle as it rolls) are called cycloids, and there are a lot of varieties: epicycloids, hypocycloids, and others, depending on how the inner circle is rolled. I once modeled the shell of gas around a supernova as an epicycloidic shell (like a peanut shell), and it reproduced what we saw with Hubble pretty well (even though it formed in a very different way than a cosmic Spirograph!).
I’ll note that when a circle rolls along a straight line, if you watch a single point on it you can break the motion up into two dimensions: Horizontal and vertical motion. These motions aren’t constant, but depend on the sine and cosine of the time elapsed. They start off motionless, accelerate to a maximum speed in the middle, then slow back down to zero … and in each direction, the point moves linearly! It’s only when you combine them that you get the cycloid.
That’s how this illusion works. By mimicking this trigonometric motion, your eyes and brain are fooled into thinking the dots are acting together, portraying the rim of a circle. But they aren’t; their motions are related but independent of one another (what’s called “parametric” in mathematics).
A-flippin’-mazing. But also MATH! And SCIENCE!
And another in a long, long series of illusions that shows very well that seeing is not necessarily believing. Our brains are very easily fooled, and that’s very important to remember in life.
Related Posts: More illusions by brusspup and others
Another Brain-Melting Illusion: The Dragon That Follows Your Gaze
An Optical Illusion You'll Swear Is Moving. It Isn't.
The Magic of Physics: A Water Spiral
Viral Illusion Will—and Should—Have You Doubting Your Eyes
The Blue and the Green (the single greatest illusion OF ALL TIME).
* Holy cow! Even in today’s app-based world, a good old manual analog Spirograph set is still available to buy! I may buy a bunch just to give to friends who have kids. Or even if they don’t.
Plunging Deep Into Colliding Galaxies
Roughly 50 million light years from Earth is the most spectacular example of galactic collision in the sky: the famed Antenna Galaxies, two huge spiral galaxies in the middle of a cosmic train wreck. Playing out over hundreds of millions of years, the gravity of the two galaxies has distorted their shapes, flung out streamers of stars a million light years long, and triggered a burst of star formation so intense that billions of new stars are being born in the galaxy’s hearts.
But not anymore! Behold Rolf Wahl Olsen’s newly-released picture of the Antennae and prepare to scrape your jaw off the floor:
Go Forth and Science
In April 2014, Slate announced its new paid membership program called Slate Plus. The Hive Overmind at Slate asked us writers to promote it and even had a contest: Whoever got the most people to sign up would get a $500 bonus.
Seeing that I have a pretty big audience here and that I was asking that audience to pay for something, it didn’t feel right to keep that money if I won. So I announced that if I did win I’d give it all to Donors Choose, a non-profit group that organizes donations to classroom teachers around the U.S. (think of it as a Kickstarter for learning).
Well, guess what? A lot of you folks signed up for Slate Plus. Enough so that I won the contest.
So I just had a delightful time going through the various science teachers’ pages at Donors Choose, looking for projects that needed funding. I found quite a lot, so I narrowed my criteria: Projects that were near full funding but just shy of the goal, coupled with good science, coupled with classrooms that needed the money, coupled with teachers who seemed to have that special quality, that spark, that got me so excited about science when I was a kid.
I found four that (literally) fit the bill: Learning in Motion (Mr. Estrada), Bringing Space to Our Room! (Mrs. Gibson), Mad Scientists Explore (Ms. Sunnucks), and Bring Vital Learning Technology to My Classroom (Ms. Carr). All four of these projects are now fully funded, and these educators can go forth and teach their kids science.
To all of you who helped out, thank you. You got more than just a subscription to Slate Plus; you helped hundreds of children across the country get a chance to explore the Universe around them.
You should feel really good about that. I know I do.
And if you like, there are plenty more worthy projects still needing funding at Donors Choose. Go.
Robert F. Kennedy Jr.: Still Fighting the Wrong Fight
Let’s get this out of the way right at the start: I’m not a big fan of Robert F. Kennedy Jr. This is almost entirely due to his grossly erroneous belief that a preservative in some flu vaccines causes autism. This preservative, thimerosal, has been tested thoroughly by many different groups and has never been found to have any connection with autism.
Got it? Vaccines don’t cause autism. It’s really that simple.
Despite this, RFK Jr. continues to beat this drum. In a recent Washington Post article, journalist Keith Kloor wrote about RFK Jr.’s attempts to talk to two senators about his crusade against thimerosal and about a new book he’s published about this topic. In the past, Kloor has been pretty matter-of-fact about RFK Jr.’s bizarre claims, so I expected this would be a pretty tough profile.
It wasn’t. Now, I don’t mean that Kloor treats RFK Jr. with kid gloves; the article actually shows his claims to be dead wrong and portrays him as an outcast from the mainstream. That’s all fine. I just don’t think Kloor really showed RFK Jr.’s true nature; something we here at Slate have seen for ourselves.
In 2013 I wrote an article giving great details on just how over-the-top anti-vax RFK Jr. is, including his giving a talk at a rabidly anti-vax conference. After it posted, Slate got a call from RFK Jr. himself, requesting a chance to rebut over the phone. I declined; having read his writings and listened to his radio shows, I knew better than to let him rail away at me.
I was right. My editor, Laura Helmuth, decided to accept the call, and was subjected to RFK Jr.’s, um, opinions, for nearly an hour. She wrote an excellent article about it, describing his conspiracy theories and how he misrepresented what scientists told him. It’s an eye-opener.
And now, with this WaPo profile, Helmuth decided it was time to reiterate this point, so she has written another takedown of RFK Jr. I highly recommend reading it; it starts with this:
Most paranoid, grandiose, relentless conspiracy theorists can’t call a meeting with a U.S. senator. Then there’s Robert F. Kennedy Jr.
… and it keeps going from there.
RFK Jr. has a lot of clout, quite a bit of which comes from his family name. But to me he is in the same heap as people like Jenny McCarthy—those who make baseless, unwarranted claims about vaccines, sowing doubt and fear about one of the greatest medical triumphs in human history. In fact, the similarity between the two is striking, since RFK Jr. claims—despite his own actions—that he is not “anti-vax”, a claim McCarthy recently made as well.
As the entire U.S. sees a huge spike in measles outbreaks, largely caused by unvaccinated people, and we’re also seeing a resurgence of other preventable diseases like whooping cough and polio (polio, for Pete’s sake!), making these outrageous claims about vaccines as RFK Jr. and McCarthy do is more than just irresponsible. It’s dangerous.*
I’ve been vaccinated my whole life, and I make sure to get my boosters as needed, too. I walk the talk. Don’t listen to people just because they have famous names. Talk to a board-certified doctor and get the facts.
* To be fair, RFK Jr.’s claims relate to vaccines that contain thimerosal, which are a tiny minority. But to be completely fair a) he’s still wrong, and b) it’s all grist for the mill for the overall anti-vax movement. Wrong is wrong, and RFK Jr.’s claims are wrong.
From the Earth to the Moon to the Earth
Forty-five years ago today—and for the first time in human history—human beings set foot upon another world.
It was one of the proudest moments in America’s history, arguably the proudest. Despite being initially motivated by small-minded territoriality, it ironically brought our planet together, with people all over the world watching breathlessly as Neil Armstrong placed his boot on the desolate surface of the Moon.
Some people fret over whether it was all worth it, taking this one small step. I have no such doubts; we are better as a species for having ventured into space. The evidence for this is overwhelming, from learning about our planet (and the dangers to it), to the very nature of humanity’s need to explore that is so fundamental to our psychology.
Venturing into space is not just something we can do. It’s something we must do.
And yet here we are. It’s been 45 years since we put men on the Moon and 42 years since the last men left it. We’ve not gone back since, at least, not with humans. Sure, we’ve made a lot of progress about living and working in space: We’ve launched several space stations, put more than 500 people into space, and built countless satellites and space probes. I’m fully aware of the awe-inspiring achievements we’ve made, and how much they mean.
But still, there is a hole in that picture. All of those people we’ve launched into orbit haven’t gone more than a few hundred kilometers above the Earth’s surface. The yawning chasm between the Earth and Moon hasn’t seen a human in it for over four decades.
Now, there's a lot to be said for low Earth orbit. It is a fantastic resource for science, and I strongly think we should be exploiting it even more. But it's not the goal. It's like walking halfway up a staircase, standing on your tiptoes, and admiring the view of the top landing.
When I look back over the time that’s elapsed since 1969, I wonder what we’re doing. I remember the dreams of NASA, and they were too the dreams of a nation: Huge space stations, mighty rockets plying the solar system, bases and colonies on the Moon, Mars, and asteroids. Those weren’t just the fantasies of science fiction. We could’ve done them. Right now, today, those dreams could have been reality.
Instead, we let those small-minded human traits flourish. We’ve let politics, greed, bureaucracy, and short-sightedness rule our actions, and we’ve let them trap us here on the surface of our planet.
It needn’t have been this way, and it still needn’t be this way. There are those who still dream, who understand the call to space, and who are devoting their lives to make it reality. We’ve faced adversity before, and have not let it stop us.
I think we can overcome our own petty blindness. Sometimes we humans look up, not down, and see not just the Universe stretching out before us, but also our place in it.
We’ve done it before and we can—we must, and we will—do it again.
Per somnia et ardua ad astra.
Cruisin’ Over the Bahamas
I just got back from travel, and now I'm deep into planning my panels for San Diego Comic-Con next week, so at the moment I'm enjoying a slow, broiling panic.
But I couldn't pass up the chance to post this breathtaking picture of the ocean around the Bahamas taken by an astronaut on the International Space Station as it sailed over on July 15, 2014:*
Yegads. You very much want to embiggen that.
The bright lights to the upper left outline Florida (the long glow is from Miami), and you can trace cities up the East Coast of the U.S. Cuba dominates the lower left (cut off a bit by an ISS solar panel), but the teal and turquoise waters are what draw the eye. The islands right in the middle are the Bahamas, and the bright glow smack dab in the middle of the picture, is (I believe) Nassau—remind me not to go stargazing there! The lights must wash out the sky. But that's probably not why people go to Nassau in the first place.
Speaking of the sky, note the green arc of light over the Earth's limb. This is called airglow, and it due to the slow release of energy from sunlight the upper atmosphere stores during the day. It's actually a fascinating physical process that I've described before. In that link I also talk about the brownish-yellow glow beneath it: That's from glowing sodium in the air, and the source of that sodium may be meteors that have previously burned up in our atmosphere!
Amazing. There's no such thing as just a pretty picture taken from space—there is always a lot more going on than you might think. And just like any artwork, knowing the story behind the beauty makes it that much more wonderful.