Bad Astronomy Blog
I recently wrote an article talking about noctilucent clouds—relatively rare high-altitude clouds usually seen just after sunset and before sunrise. They have a milky, silvery appearance, and are usually pretty hard to capture on photos.
It can be even harder from space, where lighting conditions are harsher and getting the right exposure balance is difficult. But astronaut Reid Wiseman got it just right recently, snagging a photo of the odd clouds from the International Space Station:
Conditions to create noctilucent (literally, “night shining”) clouds are touchy, which is why they’re rare. But there have been a lot seen recently—check out this astonishing photo taken over an alpine lake in Germany—and that has many folks wondering what’s going on. There could very well be a link with them and global warming, which is intriguing but doesn’t have a lot of evidence to support it yet.
But if we keep seeing more of these clouds, we may yet get a better understanding of them, and whether or not they are a canary in a coal mine of global warming.
After all these years advocating for science, and hammering away at those who deny it, I’m surprised I can still be surprised at how bad anti-science can get.
Yet here we are. Babies across the US are suffering from horrific injuries — including hemorrhages, brain damage, and even strokes (yes, strokes, in babies) — because of parents refusing a vitamin K shot. This vitamin is needed to coagulate blood, and without it internal bleeding can result.
Vitamin K deficiency is rare in adults, but it doesn’t cross the placental barrier except in limited amounts, so newborn babies are generally low in it. That’s why it’s been a routine injection for infants for over 50 years — while vitamin K deficiency is not a big a risk as other problems, the shot is essentially 100% effective, and is quite safe.
Mind you, this is not a vaccine, which contains minuscule doses of killed or severely weakened microbes to prime the immune system. It’s a shot of a critical vitamin.
Nevertheless, as my friend Chris Mooney writes in Mother Jones, there is an overlap with the anti-vax and “natural health” community. As an example, as reported by the Centers for Disease Control and Prevention, in the Nashville, Tennessee area, over 3% of parents who gave birth in hospitals refused the injection overall, but in “natural birth” centers that rate shot up to 28%. My Slate colleague Amanda Marcotte points out that vitamin K levels in breast milk are very low as well, and that’s the preferred technique for baby feeding among those who are also hostile to vaccines. In those cases, getting the shot is even more critical.
But the anti-vax rhetoric has apparently crossed over into simple injections. Chris has examples in his Mother Jones article, and there’s this in an article in the St Louis Post-Dispatch:The CDC learned that parents refused the injection for several reasons, including an impression it was unnecessary if they had healthy pregnancies, and a desire to minimize exposure to “toxins.” A 1992 study associated vitamin K and childhood leukemia, but the findings have been debunked by subsequent research. “We sort of came to the realization that parents were relying on a lot of sources out there that were providing misleading and inaccurate information,” said Dr. Lauren Marcewicz, a pediatrician with the CDC’s Division of Blood Disorders.
By “sources”, they mean various anti-science websites and alt-med anti-vaxxers like Joe Mercola (who has decidedly odd things to say about the vitamin K shot, which you can read about at Science Based Medicine). Despite the lack of evidence of harm, some parents are still buying into the nonsense, and it’s babies who are suffering the ghastly consequences.
These include infants with brain damage, children with severe developmental disabilities, and more, because of parents refusing a simple shot for their infants. The irony here is extreme: These are precisely the sorts of things the anti-vaxxers claim they are trying to prevent.
The Centers for Disease Control and Prevention has a great webpage about Vitamin K: What it is, why we need it, and why babies need it even more so. It will answer any questions you have about this necessary vitamin.
If you’re about to have a baby or have had one recently: Congratulations! It’s one of the most amazing things we can do as humans, and I will always remember watching and participating in my daughter’s birth. I would have done anything to make her ready for the world, and for me — for every parent — that includes getting the real facts about health.
Phobos is weird for more reasons, too. It orbits the planet very low, only 6,000 km or so above the surface of Mars. It moves so quickly around the planet that it actually goes around faster than Mars rotates, so it rises in the west and sets in the east—twice each Martian day.
It just so happens that the rover Curiosity is in a location on Mars where things line up just right such that every so often Phobos passes directly in front of the Sun. I’ve written about these transits before, but I somehow missed this one from Aug. 20, 2013. Happily, Robert Krulwich on his NPR blog wrote about it, to my delight.*
The photo above shows two images of the transit, which I couldn’t resist because it looks a bit googly-eyed. Someone tell Anne Wheaton and Bonnie Burton!
But those are just two images; Curiosity took quite a few … and the folks at NASA’s JPL put them together into this amazing video showing the moon moving right across the face of the Sun:
I love this video because it shows the whole transit, because the transit isn’t partial (with the moon cutting a shallow chord across the Sun, say), and because it’s in real time! The frame rate was set so that what you see here is pretty much what Curiosity saw: a 37-second long event.
On Earth, the Moon and Sun are about the same apparent size in the sky, because in a cosmic coincidence the Sun is 400 times bigger than the Moon but also 400 times farther away. Phobos is smaller than the Moon, but much closer to Mars, so it appears about half the size of our Moon. But Mars is also farther from the Sun, so the Sun looks smaller there too, and Phobos does a decent job covering it up.
It’s really odd to see something like this, knowing that what you’re seeing isn’t an airplane or a cloud, but an actual rocky moon orbiting far overhead.
… and of course, that’s nothing compared with knowing that this sequence was taken by a machine sitting on the surface of another world.
*Correction, July 28, 2014: This post originally misspelled the name of NPR.
Let me tell you about a catastrophe. I don't use that word lightly: This event was monumental, an apocalypse that was literally global in scale, and one of the most deadly disasters in Earth's history.
It began about 2.5 billion years ago (though opinions vary). The Earth was very different then. There were no leafy plants, no animals, no insects. Although there may have been some bacterial life on land, it was the oceans that teemed with it, and even there life was far simpler than it is today. Most of the bacteria thriving on Earth were anaerobic, literally metabolizing their food without oxygen.
But then an upstart appeared, and things changed. This new life came in the form of cyanobacteria, sometimes called blue-green algae.
Cyanobacteria are photosynthetic. They convert sunlight into energy and produce oxygen as a waste product. Back then, the Earth’s atmosphere didn’t have free oxygen in it as it does today. It was locked up in water molecules, or bonded to iron in minerals.
The cyanobacteria changed that. But not at first: For a while, as they produced free oxygen as their waste, iron would bond with it and the environment could keep up with the production.
At some point, though, as cyanobacteria flourished, the minerals and other sinks became saturated. They could no longer absorb the oxygen being produced. It built up in the water, in the air. To the other bacteria living in the ocean — anaerobic bacteria, remember — oxygen was toxic. The cyanobacteria were literally respiring poison.
A die-off began, a mass extinction killing countless species of bacteria. It was the Great Oxygenation Event. But there was worse to come.
Up until this time, the atmosphere was devoid of the reactive molecule. But as oxygen abundances increased, some of it combined with methane to create carbon dioxide. Methane is a far more efficient greenhouse gas than CO2, and this methane was keeping the planet warm. As levels dropped, the Earth cooled. This triggered a massive glaciation event, a global ice age that locked the planet in its grip.
Things got so bad the cyanobacteria themselves were threatened. Their own numbers dropped, along with nearly all other life on Earth. The mass extinction that followed was vast.
But there was an exception: Some organisms could use that oxygen in their own metabolic processes. Combining oxygen with other molecules can release energy, a lot of it, and that energy is useful. It allowed these microscopic plants to grow faster, breed faster, live faster.
The anaerobic species died off, falling to the oxygen-burning plants, which prospered in this new environment. Certainly, anaerobes didn't vanish from the Earth, but they were vanquished to low-oxygen environments such as the bottom of the ocean. They were no longer the dominant form of life on Earth.
It was perhaps the first of the mass extinctions life would face on our planet, and its impact resonates through the eons (and of course there is quite a lot of detail to this story). To this day, our atmosphere is rich in oxygen, with most multicellular life on Earth descended from the upstart oxygen breathers, and not the anaerobes.
It's an interesting tale, don't you think? The dominant form of life on Earth, spread to the far reaches of the globe, blissfully and blithely pumping out vast amounts of pollution, changing the environment on a planetary scale, sealing their fate. They wouldn't have been able to stop even if they knew what they were doing, even if they had been warned far, far in advance of the effects they were creating.
If this is a cautionary tale, if there is some moral you can take away from this, you are free to extract it for yourself. If you do, perhaps you can act on it. One can hope that in this climate, change is always possible.
You just never know what you’ll see when you take a picture of the Earth from space. German astronaut Alex Gerst must’ve been pretty surprised when he looked out the space station window and saw a 35-kilometer-long seahorse blowing a rainbow bubble!
That image was taken on June 21, 2014, and—not to burst your bubble—actually shows the island of Guadalupe, located about 240 kilometers off the coast of Baja California. It’s essentially two volcanoes that overlap in the north/south direction, and has ridges running along it that reach a maximum height of about 1,300 meters (0.8 miles).
In the photo (which is part of a series Gerst took), north is toward the upper right. The winds tend to blow from the west (upper left), and you can see the webbed pattern of (what I think are) stratocumulus undulatus clouds around the island. Guadalupe’s elevation splits the wind, which flows around the island, disrupting the stratus formation near it. That’s why there’s a clear spot around the island.
I suspect the clouds to the east (lower right) are flowing back toward the island due to eddies in the winds as they move around the island. You can also see a small vortex a little farther to the east, which can sometimes form in such situations. Sometimes long streamers of vortices appear downwind from such islands; these are called von Kármán vortices, and I’ve written about them many, many, many times. They’re extremely cool.
But what about that rainbow effect? What’s that?
That’s what’s called a glory. It’s an optical effect where light from the Sun gets refracted (bent) back toward the observer. To see one, you need to have the Sun directly behind you (so in a sense you’re looking down into your own shadow), and there has to be water droplets suspended in the air to bend the sunlight. As far as I can find, the exact physics going on is not terribly well understood (as opposed to what happens in actual rainbows, which is quite well known).
I see them every now and again when I fly in airplanes; I got video of one on a recent trip home from Texas:
The engine noise was loud, so I posted a transcript.
Since there’s a glory in the picture of Guadalupe Island taken by Gerst, we know the Sun must have been directly behind him as he looked down at the island. Another picture he took within minutes of the other shows the glory in a different spot. If you connect the two points, they go right over the north part of the island (the “seahorse head”). Anyone standing there and looking up would’ve been able to see the space station pass directly in front of the Sun! That would’ve made for a pretty dramatic picture itself. And what would that have looked like? Why, this:
That was taken by Thierry Legault in 2010, and shows the ISS in transit across the Sun.
I would love to see a pair of photos like these taken at the same time: A glory shining around some spot on the Earth, and at its center a photographer looking up to capture the station in front of the Sun. Of course, the presence of a glory means the sky would be cloudy for the photographer, but if the clouds were thin stratus, you’d see the Sun right through them. It’s possible.
Someone get on that, OK?
I'm very pleased to let you know that the Science Channel astronomy documentary series How the Universe Works is back on the air. The third season began a couple of weeks ago with the episode "The Sun," which focuses on the journey of a photon, a packet of light, as it makes its way out from the core through the 700,000 kilometer deep abyss of our nearest star. The second episode is "The End of the Universe," a topic near and dear to me.
Before I go on, I have to admit to being a wee bit biased about this show: I'm on it. They interview quite a few scientists in each episode, and they've been kind enough to include me now in every season of the show. I have to admit it's a lot of fun to spend a day getting barraged by questions from the producer, answering them in my own style. The overall narrative of the show is already outlined before the interviews, but we get to answer the questions the way we want. Our answers are then woven into the storyline.
I think it's a pretty good show, which is why I've agreed to come back again on it. It doesn’t overreach, sticking with a few simple themes and explaining them. The narrative storyline is fun, and the basic concepts are gone over well enough that anyone with an interest in science and a little bit of knowledge shouldn't have too much trouble understanding the show. The graphics are stunning, and whenever I watch an episode I'm amazed at what's possible to show viewers.
It's also a kick to see old friends interviewed as well. Alex Filippenko, Hakeem Oluseyi, Michelle Thaller, Sean Carroll ... these are good people I've known a long time, and I'm really happy they still get on the air. Their joy and sense of wonder shines through, and I think that's a crucial factor that makes a TV show successful. We talk about this stuff because we study this stuff, and we study this stuff because we love this stuff.
I think you will too. How the Universe Works airs weekly on the Science Channel, Wednesdays at 9 p.m. Eastern time. Check your local listings, of course. It gets repeated fairly often, so you shouldn't have any trouble catching it.
And before you ask: When you see the segments I'm in, yes, that is my telescope in the background (a Celestron C8-SGT XLT), the same one I use to capture images of the Moon, Mars, and more. If you like the show, remember: The Universe is out there, and you can observe it too. Once you're done watching TV, step outside and look up. All those things we talk about are up there.
That's one of the many, many reasons I do, in fact, love this stuff.
I am very pleased to say that two of my friends have been honored with asteroids named after them! To give a hint on who they are, the asteroids are (274860) Emilylakdawalla and (249530) Eugeniescott.
Regular readers know both of these people. Emily is a science communicator, blogging for the Planetary Society — in fact, I’ll just redirect you to her thorough and typically excellent post on her asteroid.
Genie is more than a friend of mine: She’s one of my heroes. I don’t use that term lightly. She unflinchingly defends science against those who would try to tear it down, and she did so for many years as the executive director of the National Center for Science Education. She has done battle with young-Earth creationists and climate change deniers, and was one of the people who won the day in the Dover evolution trial. And while doing all this she has been calm, genial (perhaps her name is apopros), and even downright friendly.
But don’t mistake that for weakness. She’s tough, and has weathered withering attacks from promulgators of anti-science. Her asteroid orbits the Sun out past Mars, and has withstood a billion years of solar wind and impacts from other asteroids.
It seems fitting, doesn’t it?
The idea to name an asteroid after Genie came from Bob Blaskiewicz, a skeptic and like me an admirer of Genie. He approached me a while ago asking if it were possible to name a space rock after her. Having friends in high places, I then called Amy Mainzer, Principal Investigator of NEOWISE, a space telescope that scans the skies looking for asteroids. Amy got right on it, and amazingly it only took a couple of months for the paperwork to go through. Amy’s the best.
So now Emily and Genie join the group of science advocates with asteroids named after them. I’m still tickled to be in that group myself, and hope someday to observe my namesake through my own telescope.
It’s a peculiar and wonderful thing to know that hundreds of millions of kilometers away, cold and silent, a rock a kilometer across (in my case, or a few km in the cases of Emilylakdawalla and Eugeniescott) glides through space. Will humans ever venture there some day, centuries hence? Will they wonder why the asteroid they’re visiting has the name it has?
It’s a nice thought. And with Emily and Genie, it’s a wonderful tribute to two people who try — and succeed — to make science available to everyone.
Congrats to them both.
I have a soft spot in my heart for the Hubble Space Telescope. I got my Ph.D. using observations from the venerable observatory (literally signing on to the project two weeks before the ‘scope launched into space), then got a job helping build, calibrate, and use a camera called STIS that was installed onboard Hubble in 1997.
So when I got a tweet from Gabriel Russo about getting a Lego model of Hubble officially approved, my reaction was immediate.
If you can’t figure out what it was, then reread the title of this post.
Russo’s model is amazing, and extremely cool. However, it’s not a real thing just yet. He’s submitted it to Lego’s Ideas site, which is where people can turn their ideas into real Lego kits.
Russo has done the first step, but the next step is to get 10,000 supporters to get his model reviewed by the powers that be at Lego (he doesn’t need money, just votes). He’s about halfway there, and I know there are 5,000 people reading this blog who can take a minute to register with Lego (it’s free) and give him an upvote. I did.
If it gets approved, he might be able to get it made by 2015, the 25th anniversary of Hubble’s launch. I think this model would be great for kids, adults, classrooms, space enthusiasts, and pretty much everyone. And yes, I’m doing this for selfish reasons, too.
I really want one.
Related Posts — All my WANTS
WANT Part XIX: Mercury Globe Edition
WANT Part XVIII: The Stars Underfoot Edition
WANT Part XVII: Galaxy Rug Edition
WANT Part XVI: The DANGER WILL ROBINSON Edition
WANT Part XV: Moon Credenza Edition
WANT Part XIV: Citric Acid for Blood
WANT Part XIII: Moon Throw
WANT Part XII: Earth Globe Fire Pit
WANT Part XI: To Boldly Slice
WANT Part X: The TARDIS. A REAL TARDIS!
WANT Part IX: Levitating TARDIS Edition
WANT Part VIII: Zen and the Art of Apollo Maintenance
Want: Part 6
Want: Part V, Lunar Furniture Edition
Want: Part IV
Want: Part III
Want: Part II
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?
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.
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!
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.
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.
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.
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 (you'll want to make your browser wider for this):
That magnificent shot was taken with — get this — a 32 cm (12.5”) telescope Olsen built himself. It took him 38 nights of observing from January to June of 2014 to get to a total of an amazing 75 hours of observing time for this gorgeous image. He says the faintest stars visible are around 24th – 25th magnitude; the faintest star you can see with your naked eye is 25 million times brighter than that.
So yeah, this picture is deep.
The detail really is stunning. Olsen compared his image to those taken with Hubble and the VLT, and while of course his resolution isn’t as good (there’s no way a small telescope can discern details as well as much larger telescopes) it’s amazing what features you can identify in his shot compared with the professional observatories.
What you’re seeing in this image are two massive galaxies undergoing a physical collision. Over the lifetime of the Universe, galaxies collide fairly often; our own Milky Way has collided with and consumed quite a few smaller galaxies to grow to its current size. But collisions between two large galaxies is more rare, and we’re fortunate to have such a fantastic example like the Antennae so close to us.
The collision started more than 600 million years ago. As they approached each other, their mutual gravitational attraction drew out long streamers of stars (called tidal tails) from the other. The galaxies aren’t colliding perfectly head-on, but instead first missed each other by a bit. Their gravity swung the two galaxies around, giving them a bit of rotation; that’s why the tidal tails form long, graceful arcs.
After they swung around, the galaxies headed for each other again, colliding for a second time and starting the long, long process of merging into a single, larger galaxy. Amazingly, it’s unlikely there will be a single collision between two stars; stars are very small compared to the space between them. But gas clouds are huge, light years across, and collisions between them are common in these events. When clouds slam into each other they collapse and form stars. These collisions can spur huge amounts of such activity, creating what we poetically call a starburst. In Olsen’s image, the clouds are pink and red due to glowing hydrogen gas, excited by the vast numbers of massive stars forming within them.
Star birth also creates huge amounts of dust — long, complex molecules based on carbon — which is opaque, so the dust clouds block the light from stars behind them. You can see the ribbons and filigrees of dust in Olsen’s image, and of course even better in the VLT and Hubble pictures.
If you still need one more thing to send chills down your back, then think on this: In four billion years the Milky Way will collide with the massive Andromeda Galaxy, and if there are any spectators a few dozen million light years away, what they will see all those eons hence will look very much like what Olsen has shown us here.
It’s simply mind-blowing to see what can be done with so-called “amateur” equipment these days. What was once the sole purview of professional observatories (before the invention of the digital camera) can now be reproduced with far less, if someone is willing to be so devoted to it. I’m glad Olsen is.
And if you need more of his work, then you should see his images of the active galaxy Centaurus A, his glimpse of a forming alien solar system, and what he did with Voyager images of Neptune. It takes him a long time to put together each of these shots, and so we don’t hear as much from him as other folks putting their eyepieces to the sky. But if he continues to create such astonishing works like these, I can be patient. It’s worth it.
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.
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 take-down 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 US 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.
45 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 over 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.
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.
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 breath-taking picture of the Caribbean 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 US. Cuba dominates the lower left (cut off a bit by an ISS solar panel), but the teal and turquoise waters of the Caribbean are what draw the eye. The islands right in the middle are the Bahamas, and the bright glow to their right, 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 which 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.
[With apologies to Ernie.]
Right now, in deep space 400 million kilometers from Earth, the European Space Agency probe Rosetta is easing its way toward the comet called 67P/Churyumov-Gerasimenko (which, for obvious reasons, I’ll just call ChuGer). On July 14 it was a mere 12,000 km (7400 miles) from the comet — less than the diameter of the Earth! It took a series of images of the frozen iceball, and it’s becoming very clear that this comet is really, really weird:
It’s not an iceball… it’s an ice rubber duckie! And a big one, about four kilometers across.
As you can see, it appears to have two distinct components; a large, flattish piece and a smaller, rounder one attached off-center. You can see this a lot more clearly in an animation composed of 36 images taken about 20 minutes apart:
What the what? Note that the comet is only a couple of dozen pixels across as seen by Rosetta; the images in the animation (and on the right in the still image above) have been smoothed to give you an idea of what it looks like. Don’t take small details too literally, but the overall shape is apparently real.
It’s not clear why it has this shape, but there are several possible explanations of how it may have been molded this way.
Comets are big lumps of frozen water with dust and rocks mixed in. In fact, we sometimes call them “dirty snowballs”. It’s possible that two comets suffered a very low speed collision and stuck together, forming the weird shape.
However, that strikes me as very unlikely. Why? Space is big. That’s why we call it “space”. The odds of two comets coming that close together at just the right speed and angle to do this seem very low to me.
It’s more likely, in my mind, that ChuGer got whacked by a much smaller object, say a chunk of asteroid. Some comets aren’t solid, like rocks, but more like loosely bound rubble piles held together by the ice. Over the eons, small impacts would shatter it, creating deep cracks inside the comet. A slightly bigger collision could actually dislodge large chunks. If the impact speed were right, the big chunks might separate a bit and then slowly re-accrete over time due to their feeble gravity. What you’d get is a weirdly-shaped object, like if you took a small snowball and stuck it on the side of a bigger one.
Which is just what we see with ChuGer. I’m totally guessing here, but I have a sneaky suspicion that’s what we’re seeing.
Another way it could have gotten this shape is that it used to be rounder and smoother, but over time eroded away. Comets have lots of ice, and as they approach the Sun that ice turns directly into a gas (which is called sublimation) and streams away. Anything less volatile (like rocks inside) will remain. If the comet has big lumps of rock inside it, or just big pockets of ice distributed through it, it could erode asymmetrically, leaving huge lumps like ChuGer’s.
Again, I’m guessing. We’ve only visited a handful of comets spacecraft, and to be honest they’re all weird. Halley is a lumpy potato. Hartley 2 looks like a bowling pin or a dumbbell, with lobes made of carbon dioxide and a waist of frozen water. Other comets have been found to be similarly lobed, lumpy, and basically asymmetric.
The whole point here is that we’re exploring — we don’t know what we’ll find. If we did, it wouldn’t be exploring.
And we’ll find more, much more. Rosetta is still approaching ChuGer, and in early August will be a mere 100 km (60 miles) from the comet. It will enter orbit, examining the nucleus (the solid part of the comet) in excruciating detail. Then, in November, it will send out a lander named Philae to physically touch down on the comet’s surface! It will examine the comet and send the data back to Earth via Rosetta. Its planned mission will last about a week, and should be a huge bounty for astronomers and planetary scientists.
Over the next weeks I’ll be writing more about this amazing mission and the strange comet it’s studying. ESA doesn’t have the same policy of freely releasing images that NASA does, but hopefully when something new and spectacular is available, you’ll be able to read all about it here.
In the meantime, you can take a look at some of the amazing highlights from the Rosetta mission so far, including some jaw-dropping images of Earth, Mars, an asteroid named Lutetia (with a fantastic gallery), another lumpy diamond-shaped asteroid named Steins, and a lovely shot of the Moon rising over the limb of the Earth. These images show the promise of what we’ll see very, very soon once Rosetta is in orbit around 67P/Churyumov-Gerasimenko.
Robert Gendler is the gift who keeps on giving. He’s an accomplished astrophotographer (why, I would never make such a claim without ample evidence) who takes observations from professional observatories and adds to them images he’s taken himself and with other people. The result is substantial beauty… and here’s another bit of proof for you in the form of the ridiculously chaotic star-forming nebula NGC 1333:
This cloud is a sprawling stellar nursery, a dense cloud that’s still collapsing, fragmenting, and creating stars hither and yon. One feature of many young stars is that they rotate rapidly, and are still surrounded by the thick disk of gas and dust from which they formed. Their still-intense magnetic fields get wound up like a corkscrew, and this can launch twin beams of matter out from the poles of the star.
These are called Herbig-Haro stars, and NGC 1333 is littered with them. I found several perusing Gendler’s image, and inset one here. The cloud is choked with thick, opaque dust which hides a lot of the details. Infrared light can pierce that veil, though, so images from observatories like the Spitzer Space Telescope can reveal far more details. In fact, in that linked article I have an in-depth discussion both of this nebula and the HH objects in it (and a close-up of one that actually has curved beams, which are lovely). I suggest giving it a read to truly grasp the awe-inspiring nature of this object.
Gendler’s image is comprised of observations from the 8.2 meter Subaru telescope, the Digitized Sky Survey, telescopes with the NOAO, and his own data in collaboration with Roberto Colombari. These are magnificent telescopes, one of the reasons the final image is so spectacular. Another is that NGC 1333 is only about 1000 light years away, relatively nearby on a galactic scale (the Milky Way is 100,000 light years across). This makes it one of the closer massive star-forming regions in the galaxy, so we get a little more detail than we otherwise might.
It always amazes me that so much science can be found in objects so beautiful. I wonder what this tells us about our minds, our perceptions, and how we evolved to appreciate beauty... and how useful an ability like that can be?