The entire universe in blog form

Oct. 23 2014 7:30 AM

Our Solar System and Galaxy … Seen by an Astronaut

First off, let’s get this straight: If you use Twitter, you should be following space station astronaut Reid Wiseman. He posts amazing photos all the time, and your life will be the better for it.

For example, on Sep. 28, while orbiting over the Sahara Desert, he took this stunning photo:

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Oct. 22 2014 12:30 PM

Update: Sunspot 2192’s X-Class Flare

flare
Yes, the affected region on the Sun from this flare is a dozen times wider than our entire planet.

Photo by NASA/SDO/helioviewer.org

Just a quick update: Sure enough, as predicted, the freakishly huge sunspot AR 2192 blew out a powerful X-class flare today around 14:00 UTC. The picture above shows the view from the Solar Dynamics Observatory; in the far ultraviolet it’s very sensitive to solar activity. Note the Earth for scale there, in case you need the Universe to crush your feeling of self-importance under its heel.

Flares are massive explosions on the Sun associated with sunspots. You can read about them in detail in an earlier post I wrote, but the quickie version is that magnetic fields in sunspots can store vast amounts of energy. Looping magnetic field lines can get tangled up and snap, releasing their energy as mind-crushing explosions called flares. They’re rated by how much X-ray energy they emit; for example M-class are “moderate”, and X-class are the highest.

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Today’s flare was an X 1.6, which is fairly powerful. And by “fairly,” I mean it exploded with the energy of something like a million times the combined yield of every single nuclear weapon on Earth.

So yeah, bit of a big bang there.

flare energy
Today's flare just topped into the X-class level, as measured by the GOES satellite. There was a smaller M flare that erupted two hours after this one, too.

Graph by the Solar Weather Prediction Center

We’re in no danger on Earth from this flare. There are likely to be radio blackouts and minor issues like that, but that’s probably it. We may get some aurorae and such, too, so keep your eyes on SpaceWeather.com for info on that.

AR 2192 is the largest sunspot complex seen in more than a decade, going back at least to when this solar magnetic cycle began. It’s been huffing and puffing, putting out a bunch of M flares, and this is the second X flare in as many days. It’s quite likely to continue this rude behavior for a while, and if there’s more news, I’ll let you know. 

Oct. 22 2014 10:30 AM

Monster Sunspot Will Make Thursday’s Eclipse That Much Cooler

Right now, a truly ginormous sunspot is turning its baleful eye toward Earth.

The spot, called Active Region 2192, is a bit hard to wrap your brain around: Its dark core is easily big enough to swallow the Earth whole without it even coming close to touching the sides, and the whole region is several times larger than that, easily more than 100,000 kilometers across. It’s the biggest sunspot we’ve seen this solar cycle (bigger than one I reported on in January that was also huge).

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It’s feisty, too, having blown off a series of moderate M-class solar flares recently, and one that edged into X-class. We’re expecting more from it as well, so stay tuned to SpaceWeather.com, SpaceWeatherLive.com, and Realtime Flares on Twitter for up-to-the-moment news about any big eruptions. [Update (Oct. 22 at 15:00 UTC): Yup. AR 2192 blew off an X1.6 flare at 14:00 UTC today.]

When I saw pictures of it a couple of days ago, I knew it would be big enough to see without binoculars or a telescope. Using just my solar viewing glasses (which are rated safe to use to view the Sun; see here for more) I easily saw the sunspot with my own eyes as a black blemish near the Sun’s edge. Holy wow!

I decided to try my hand at getting a shot of it. Sacrificing a pair of solar glasses, I rigged up a small filter for my camera, went outside, and got this:

AR 2192

Photo by Phil Plait

Not bad! You can see AR 2192, as well as a few other spots (including the small one near the Sun’s edge that is visible in the SDO picture at the top of this post).

Clouds started rolling in, but far from being discouraged I figured that might actually make for a dramatic scene. I was right:

sun_oct212014_clouds
Spooky.

Photo by Phil Plait

Nifty. And good practice; I want to make sure I’m ready for the partial solar eclipse tomorrow.

Speaking of which, let me repeat my call: If you get good and clever shots of the eclipse, please let me know! I want to post a gallery of a half-dozen or so. Make sure you tell me where you took them, what equipment you used, and whether they’re also online (so I can link to you).

Oct. 22 2014 7:30 AM

An Illusion That Makes Me Happy and Sad

I’m normally a pretty cheerful guy, though I do have my moods. I’m not very good at hiding them, either, I’ll admit. So when you look at the photo below, would you say my mood as depicted on the left is the same as on the right, when the picture is inverted?

philplait_upsidedown
This was not taken when I visited Australia.

Photo by Chris Setter/Phil Plait/Optical Spy

You might. But if you do, your brain has fooled you: You’ve become a victim of its wonky way of perceiving the world.

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Don’t believe me? Take a look at the same two pictures flipped upside for proof:

philplait_upsidedown_2
Aiiiiiiieeeeee!

Distressing, isn’t it? This image comes from Optical Spy, and it’s an example of a well-known but still not completely understood effect called the Margaret Thatcher illusion. Yes, seriously, that’s its name. The illusion was first published using an image of the prime minister, and the name has stuck. Optical Spy has done this trick with quite a few skeptics and other well-known illusion-lovers; I was surprised and pleased to find my own goofy mug there.

As you can see, the first images are the same, except in the one on the right my eyes and mouth have been individually inverted (this process is called—yes, really—thatcherization). When the whole picture is then flipped, our brains have a hard time seeing it. Yet it becomes glaringly obvious when that image is flipped back. Whoever did the image of my face did a good job blending the edges of the edited regions; usually the pictures are just cut-and-paste, making it even weirder looking.

What’s even more interesting about this illusion is that no one knows exactly what causes it. Clearly, we recognize faces using individual pieces of the face—the eyes, nose, mouth, and so on. Our brains recognize faces even when there are only hints of those features, too, and even when they’re clearly random patterns, like in clouds, wood grain, flowers, gas clouds in space, or rocks on Mars. Even sometimes in other places where you would not expect to see a face. This psychological effect is called pareidolia, and is very strong; after all, the canonical smiley face is just two dots and a curved line, yet we see it as a smiling face!

Clearly, our ability to recognize faces is relational, that is, we see pieces of the whole in relation to one another. But it’s configural as well; that is, how those pieces are arranged. For some reason that part is lost when a face is inverted, and that is the subject of debate among psychologists. You can read a good synopsis of it on Mixing Memory, or more detail in a research paper about it, and of course a simple explanation is on Wikipedia. By coincidence, an article on testing this effect on monkeys (with interesting, positive-seeming results) was just posted on io9, too.

As for my own photo, that was taken by my brother-in-law for the cover of my book Death From the Skies! Now I’m wondering if we should’ve used the thatcherized version. It seems like a better match with the theme of the book.

Tip o’ the Necker cube to the many folks who sent me the link to the Optical Spy page.

Oct. 21 2014 7:00 AM

Watch the Moon Eat the Sun: The Partial Solar Eclipse on Thursday, Oct. 23

On the afternoon of Thursday, Oct. 23, 2014, the Moon will pass in front of the Sun.

What we’ll see is a partial solar eclipse, where the Moon passes along a chord of the Sun’s face, never completely blocking it out. At maximum eclipse the Sun will look like a thick crescent, the dark disk of the Moon moving across it.

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This is a very cool event, and it favors Canada and the United States; it’ll be visible in nearly the entirety of both countries. The exception is the extreme northeast, where the Sun will be setting as the eclipse starts (whether you see anything or not from that area depends on your exact position; see below).

Fairly Warned Be Ye, Says I

First, let’s get this out of the way: NEVER LOOK AT THE SUN WITHOUT PROPER FILTERS. You probably won’t do severe or permanent damage to your eyes by glancing at the Sun with your eyes alone, but I’d advise against it (especially for younger children, who have clearer lenses in their eyes that let through more damaging UV light)—and certainly against anything longer than a very brief glance.* AND DON’T EVER EVER EVER LOOK AT THE SUN THROUGH A TELEPHOTO LENS, BINOCULARS, OR A TELESCOPE without proper filtration, and honestly, unless you really know what you’re doing, just don’t do it.

You might think sunglasses are OK, but they’re generally not. They can make it worse; they block visible light from the Sun, so the pupil in your eye widens. That can let in more harmful UV and infrared light.

If you want to see this event properly and safely—and you should, because eclipses are very cool—I urge you to find a planetarium, observatory, or local astronomy club near you and let experts handle the equipment for you. They might even have a pair of eclipse glasses you can use. (It’s too late to order ones now, but there will always be more eclipses so I suggest you order some; they’re cheap.)

I have more about safely observing the Sun in a post about the Venus Transit from 2012; I strongly urge you to read it before going out to take a look.

OK, So What Does All This Mean?

Here’s how this works. The Moon orbits the Earth once per month, and the Earth orbits the Sun once a year. The Moon’s orbit is tilted to Earth’s orbit by about 5°, so as it goes around the Earth it passes through the Earth’s orbital plane every two weeks or so. If the Moon’s orbit weren’t tilted, we’d get a solar eclipse every month when the Moon passed between the Earth and Sun. Since it is tilted, though, sometimes it’s “above” the Sun at new Moon, and sometimes “below.” We only get eclipses rarely because the Moon has to be crossing the plane of Earth’s orbit at the same time as it’s new Moon, so that it gets exactly between us and the Sun.

diagram of the Moon
Sometimes the Moon's orbit takes it "above" the Sun as seen from Earth (1), and sometimes "below" (2). If things line up just right (3) we get a solar eclipse.

Diagram by Phil Plait, artiste extraordinaire

On Oct. 23, the geometry is close but not quite perfect. Instead of passing directly in front of the Sun, cutting straight across it, the Moon passes the Sun at an angle off-center, so it only partially blocks our star. That’s why this is a partial eclipse, and not a total one.

In a lunar eclipse, the Earth gets between the Sun and Moon, and casts its shadow on the Moon. The event happens on the Moon, so everyone on Earth facing the Moon sees it at pretty much the same time.

But a solar eclipse is the Moon casting its shadow on Earth. The Moon is moving, orbiting us, and the Earth is rotating as well, so what you see and when you see it depends on where you are. (It’s like sunset, which you see at a different time than someone east or west of you.)

BA_141020_eclipse
Animation looking down on the Earth during the eclipse.

Animation by Fred Espenak/NASA

On the left is an animation showing the view from above the Earth, looking down on the U.S. during the eclipse. The curved line sweeping around clockwise is the terminator, the day/night line. The big gray distorted circle is the physical shadow of the Moon. You can see that over time it moves roughly eastward and southward, the combination of its motion and the Earth’s spin. If you live anywhere inside the path of that shadow, you’ll see an eclipse. The closer you are to the center of the shadow, the more of the Sun will be blocked.

So when will you see it? If you happen to live near a big city, here’s a table showing eclipse times, and there’s also an interactive page where you can enter your location and it’ll tell you when the eclipse happens.

As an overview, here’s a map showing timing and percentages of the Sun blocked.

map
Map of timing and location of the eclipse. See text for description.

Drawing by NASA/Fred Espenak

It looks daunting, but it’s not that hard to interpret once you get used to it. The more-or-less horizontal curves are marked 0.20, 0.40, 0.60 and 0.80; those are telling you how much of the Sun is blocked. I’m in Boulder, Colorado, just south of the 0.60 line, and so the most I’ll see is about 56 percent of the Sun blocked. That’s not enough to really notice it getting any darker out.

The more-or-less vertical lines tell you the time of greatest eclipse in UTC (subtract 4 hours for Eastern, 5 for Central, 6 for Mountain, and 7 for Pacific times). Boulder is just to the east of the 22:30 UTC line, and for me I’ll see the most amount of Sun blocked (what’s called greatest eclipse) at about 22:34 (16:34 or 4:34 p.m. local time).

Viewing and Photographing the Eclipse

First off, again, here are some tips on how to safely observe the Sun, and you can find a lot more here. I’ll reiterate a few here.

If you have certified eclipse/solar viewing glasses, you’re OK. These are designed to block the dangerous IR and UV light from the Sun, while cutting way down on the visible light. The Sun looks like a small disk, and the eclipse will look really cool just like that. Again, don’t use sunglasses, even if they are UV blocking! They can actually increase the damage to your eyes.

I’ll add here that there is a monster sunspot (AR 2192) that is crossing the Sun’s face right now, and that’ll make a very dramatic feature to see during the eclipse.

If you have a pair of binoculars you can use them to project the Sun on a piece of white paper. Again, seriously, don’t look through them at the eclipse unless boiling your eyeballs is something you’re hoping to do. Also, be warned: The Sun can heat up the inside of your binoculars, and can damage them. I’ve used this technique many times with no problem, but I have pretty decent equipment. Plastic lenses, for example, might not fair well. Proceed at your own risk.

First, block one of the big lenses with a lens cap or something opaque, so you’re only using one half of the binoculars (otherwise you get two images). Get a big piece of white paper (poster board is great for this) and prop it up facing the Sun. Hold the binoculars so that you can see the shadow of them on the paper. Orient them so that the shadow of the binoculars is as small as possible; when they’re aligned with the Sun you’ll see an image of the Sun on the paper. Move the binocs toward or away from the paper to get the Sun the right size, and focus them. This takes some practice, but after a few minutes you’ll get the hang of it.

You can also do a variation of this projection method with a telescope, but I really, really don’t recommend it. ‘Scopes gather a lot of light and focus it down into a tight beam, and that can severely damage eyepieces and/or the telescope itself. And NEVER use one of those little “Sun filters” to screw into your eyepiece! Those can heat up and crack, and under some circumstances shatter, sending glass shard outwards at high speed. Not a good idea.

If you happen to have a telescope with a Mylar Sun filter that goes over the front end of the ‘scope then you’re probably OK. Just make sure you know what you’re doing. I’d hate to see anyone get hurt, or equipment get damaged, from observing the eclipse.

And finally, if it’s cloudy where you are, don’t despair! Eclipses are always live-streamed from various locations, so you’ll be able to watch it on your computer. The Coca-Cola Space Science Center will have a webcast, and I’ll add more here as I find out about them.

Update, Oct. 22, 2014 at 04:00 UTC: My friend and astronomer Adam Block is doing an eclipse live stream from the Mt. Lemmon SkyCenter in Arizona. This should be high on your list! That's a great location and observatory.

Update, Oct. 23 at 15:00 UTC: Griffith observatory in L.A. will be open to the pubic for observing the eclipse and will also have a webcast.

Update, Oct. 23 at 16:30 UTC: My friend Scott Lewis is doing a live webcast of the eclipse; you can find links at the Know the Cosmos website.

The next solar eclipse is on March 20, 2015, visible from Europe and Asia; the next one visible from the U.S. will be the great total eclipse of Aug. 21, 2017, which will cut right across the heart of the country. That one will be a big deal.

So if you’re in North America, try to catch this one; it’ll be three years before the next. There’s something wonderful and, yes, other-worldly about eclipses, even partial ones. If you get a chance to watch (safely), take it. And if you do get pictures, send me links (either via email, or on Twitter)—I’m hoping to put up a gallery of the most clever and cool ones. I have a gallery from the May 2012 solar eclipse that might give you some inspiration.

*Update, Oct. 22, 2014 at 04:00 UTC: I originally wrote, "You probably won’t do severe or permanent damage to your eyes by looking at the Sun with your eyes alone..." and should have been clear that simply glancing is likely not a problem, but looking for longer could be.

Oct. 20 2014 7:00 AM

Gallery: The Red Planet and the Comet

Yesterday, Oct. 19, at approximately 18:30 UTC, Mars got buzzed by a comet.

The comet, named C/2013 A1 (Siding Spring), passed just 130,000 km (80,000 miles) above the surface of Mars, the closest cometary encounter with a terrestrial planet ever seen (the adjective is because Jupiter has been hit by several comets and asteroids in the past few years).

Siding Spring is an Oort cloud comet, meaning it came from the very remotest regions of the solar system, almost certainly plunging into the inner system for the first time after billions of years in the dark. It chose quite a path for its first trip here! Mind you, the comet got three times closer to Mars than the Moon is to Earth. This was a close shave indeed.

NASA and other space agencies took precautions, moving their orbiting probes to the far side of the Red Planet during closest approach, while the rovers were pretty much on their own. Happily, they all appear to be fine, even after the comet dropped tons of material into the atmosphere at dozens of kilometers per second.

We’re still awaiting images taken from those probes, but in the meantime, quite a few dramatic pictures were taken from Earth. Here are a few of the ones I like best…

Oct. 19 2014 7:30 AM

Persistence Pays Off: The Smoking Trail of a Shooting Star

On Oct. 16, 2014, a redditor by the handle -545- was camping at the Ashton-Wildwood County Park in Iowa. He spotted a clearing in the trees near his campsite which framed a part of the sky, so he set his camera up to take a series of 10-second exposures in the hopes of getting good footage for a time-lapse video.

What he got was better than good: He caught a bright meteor that left a persistent train, a trail of glowing vapor that lasted for quite some time:

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That’s pretty amazing timing and framing. The meteor appeared right in the middle of the hole in the trees, and the meteor must have appeared very early in the 10-second exposure that first shows it; you can already see some of the vapor trail it left behind. For those keeping track at home: The brightish star to the right of the meteor is Gamma Triangulum, the star above the middle of the streak is 1 Tri, and the little diamond to the left is 12 and 13 Tri with two fainter stars (HD15226 and HD15326); it took me a while poring over my planetarium software to nail this down!

meteor
Three frames from the series showing the meteor and glowing vapor trail blown by winds. Click to bolidenate.

Photo by redditor -545-, used by permission

This sort of event is pretty rare, though not unheard of (I have several blog posts showing them; see Related Posts below). A meteor is just a small chunk of rock, ice, or metal that’s orbiting the Sun, and the Earth gets in its way. As it plunges through our atmosphere at high speed, it violently compresses the air ahead of it, heating it. This in turn heats the meteoroid (the solid bit of interplanetary debris; as it burns up it’s called a meteor, and if it hits the ground it’s a meteorite), which glows and leaves behind the bright but generally short-lived trail.

But the event can also ionize the air, stripping electrons from their parent molecules. As the electrons recombine, they give off a bit of light. This is called a persistent train, and some have been known to last for many minutes. The train is roughly 80–100 km above the ground, and upper atmosphere winds blow it into twisting, eerie shapes.

meteor
Wide angle shot showing the clearing in the trees that beautifully framed the event.

Photo by redditor -545-, used by permission

-545- really nailed this one! You might think he was lucky, but it’s not luck. It’s persistence. Events like this happen, and if you go outside enough, watch the sky long enough, take enough pictures … you’ll wind up with something amazing.

And if you do see a bright meteor (sometimes called a fireball or bolide), make sure you note your time, location, and the direction you saw it. Then you can report it to the American Meteor Society, which collects these data. Sometimes this can help recover meteorites if there are any!

Tip o’ the Whipple Shield to reddit, and the many, many people who sent this my way.

Related Posts

Oct. 18 2014 7:30 AM

Mars and the Comet: The Countdown 

On Sunday, Oct. 19, 2014, at about 18:30 UTC (14:30 Eastern), Mars will experience a very close encounter with a comet. 

The comet C/2013 A1 (Siding Spring) will pass just about 130,000 kilometers (80,000 miles) from the surface of Mars. There is no danger of an impact, but the planet will pass through part of the comet's tail (which is composed of gas molecules and dust).

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NASA and other space agencies have taken precautions to make sure the spacecraft at Mars won't be hurt, but they're also hoping to capitalize on this unprecedented opportunity to see a comet VERY up close and personal. I'm not sure just when we'll start seeing data from them, but I highly recommend keeping an eye on Emily Lakdawalla's blog page and her Twitter feed. She is really great about staying up to date and relaying accurate information as soon as she has it. 

I'll try to keep up as well, and if anything interesting happens I'll let you know. It's generally a good bet to follow me on Twitter too, as I'll be linking to things there, including news from other folks as it's confirmed.

Update, Oct. 18 at 15:30 UTC: The Virtual Telescope Network will be streaming images of the comet and Mars live starting at 16:45 UTC Sunday. 

Update 2, Oct. 18 at 19:00 UTC: D'oh! I forgot to say: Also follow Karl Battams on Twitter, and keep your finger on the refresh button of the Coordinated Investigation of Comets page. Tons of info there!

Update 3, Oct. 19 at 18:00 UTC: ESA is holding a live webcast about the comet encounter. Due to technical difficulties, the ESA live 'cast has been moved to a Google Hangout.

A thought: The NASA comet page says the coma (the big fuzzy cloud of gas surrounding the solid nucleus of the comet) is about 20,000 km across. At closest approach, that means that if you were standing on Mars, the comet would appear to be over 8° across! That means that if you have a big hand, you could just barely block it with your upraised fist.

That's astonishing. What a view that would be! And while the astronomer part of my brain is envious and wishes we could see something like that from Earth, the human part of my brain is screaming obscenities at the astronomer part of my brain. In real life, it's probably best comets keep their distance from us.  

Oct. 17 2014 11:00 AM

Figuratively Shiny: A Firefly Video

Firefly went off the air more than a decade ago now,* but even with the movie Serenity there’s been a Mal-shaped hole in the hearts of fans, including me.

Perhaps now that cavity can be filled in a little bit. The company Lootcrate, with producer and director Julian Higgins, has created a fan-made short video called “The Verse,” about a different crew in the same universe as that of the good ship Serenity. Here’s the thing: It’s really, really good. Seriously. If you’re a Browncoat, you need to watch this right now.

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See? Told ya. And I’m not the only one who thinks so. Given the time span since the series ended, a reunion show seems pretty unlikely. But I could get into this new crew, I think. And hey, did I spy Vic Mignogna, who plays Jim Kirk in Star Trek Continues, another fan-made production? That must’ve been on purpose.

It’s pretty amazing what dedicated and talented fans can do. And we’re seeing more and better Web series all the time, too. This Internet thing may just have a future to it.

*You kids get off my ‘verse!

Oct. 17 2014 7:30 AM

Literally Shiny: A Firefly Video

After living practically my whole life on the East Coast, one of the things I didn’t count on when I moved west was the lack of fireflies. They were such a ubiquitous phenomenon, such a part of the environment, that it never occurred to me that they might not be everywhere in the States.

But they don’t live in California, where I lived for seven years, or in Colorado, which I’ve called home for the better part of a decade now. I miss them.

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But it helps a lot to see this lovely time-lapse (kinda) video of fireflies, shot by Vincent Brady.

Nice. And he used a clever technique for some of the effects. A video is really just a series of still images played rapidly, fooling your brain in to seeing motion. Brady took thousands of still images and strung them together to make the video. For some, he let the frames fade in, linger, then fade out again. The end result is you see the light from the fireflies persist for a few seconds before dimming, with insects at all different distances creating a stop-motion-like dance.

Incidentally, the compound that generates the light is called luciferin (Lucifer was the mythological bringer of light), which is the same class of substrate used by dinoflagellates to glow. I spent an evening kayaking on a lake filled with such protists, and watching the blue sparks fly every time I put the oar in the water was magical.

Nature is amazing. It’s wonderful what happens if you take hydrogen, helium, and a splash of lithium, and let them mix for a few billion years.

Tip of the adenosine triphosphate to Boing Boing.

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