The entire universe in blog form

July 29 2014 9:15 AM

Noctilucent Clouds … Frooooom Spaaaaaace!

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:

noctilucent clouds
An eerily glowing noctilucent cloud above the curved edge of the Earth, as seen from the space station. Click to embiggen.

Photo by NASA

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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.

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July 29 2014 7:30 AM

The Littlest Victims of Anti-Science Rhetoric

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 U.S. 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.

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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 more than 50 years—while vitamin K deficiency is not as big a risk as other problems, the shot is essentially 100 percent 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, more than 3 percent of parents who gave birth in hospitals refused the injection overall, but in “natural birth” centers that rate shot up to 28 percent. 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 Web page 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.

July 28 2014 11:00 AM

Phobos’ Googly-Eyed Transit

Mars has two moons: Phobos and Deimos. Both are lumpy, rather irregular potatoes, and quite small. Deimos is only 15 kilometers along its long axis, and Phobos is about 27.

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.

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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.

July 28 2014 7:30 AM

Poisoned Planet

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.

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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.

cyanobacteria
Modern cyanobacteria, magnified 2400x. A distant ancestor of this plant changed the entire planet.

Photo by Josef Reischig via Wikipedia

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.

July 27 2014 7:30 AM

The Glory of Guadalupe

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!

Guadalupe island
Guadalupe Island seen frooooom spaaaaaace. Click to hippocampusenate.

Photo by NASA

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).

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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:

ISS transiting the Sun
The space station transiting the Sun. The sunspot to the upper right is about the same size as the Earth ... but a lot farther away than ISS.

Photo by Thierry Legault, used by permission

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?

Tip o’ the lens cap to Peter Caltner for finding the photos in the NASA database, and of course to Alex Gerst for taking them.

July 26 2014 7:30 AM

How the Universe Works: Season 3

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.

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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.

Phil Plait
Hey! I know that guy!

Photo by Discovery Network

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.

July 25 2014 7:30 AM

Space Rocks for Two Science Promoters

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.

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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?

asteroid eugeniescott
Eugeniescott orbits the Sun well past Mars. She can really hold her breath a long time.

Illustration by NASA/JPL

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 kilometers 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.

July 24 2014 11:00 AM

WANT Part XX: Hubble Lego Edition

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.

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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

July 24 2014 7:30 AM

What Is This Mystery Object in an Astronaut’s Photo?

Pictures of the Earth taken from the International Space Station are endlessly fascinating. Sometimes the locations are obvious, and sometimes not so much.

And sometimes we get a mystery. I have one of those for you today.

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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, at about 11:57 UTC, he found three in a row that showed a curious thing. Here’s one of them:

Aurora, ISS, Earth
An aurora, the ISS, Earth ... and something else. Click to closeencounternate.

Photo by NASA

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:

iss_satellite_590
Satellite, debris, or meteor?

Photo by NASA

Some things to note: The first picture had an exposure time of 0.2 seconds, the second one was 0.4 seconds, 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 four times 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 kilometers (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.

rongaran_perseid_590
A perseid meteor photographed by Ron Garan from the ISS in 2011. Click to get more info.

Photo by NASA

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.

Arg again!

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?

July 23 2014 1:00 PM

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.

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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.

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