Last month, scientists using the GOCE spacecraft released a model of the Earth’s geoid: essentially, a shape telling you which way is down. If the Earth were a perfectly smooth sphere of constant density throughout, gravity would pull you straight down to the center (perpendicular to the surface). But if a dense hill were nearby, the gravity of that hill would change the direction of the force of gravity. The geoid maps that, and is very useful to understand things like ocean currents and such.

The resulting geoid resembles a bizarre, lumpy Earth. It was pretty neat, but now Nathanial Burton-Bradford has made it better: he took the data and made 3D anaglyphs!

This one shows the view over North and South America. It doesn’t look like much to the eye, but if you have red/green or red/blue 3D glasses, the 3D jumps right out at you. He has lots more of these from various angles over the Earth’s geoid model, and man are they weird. There’s something truly odd about seeing the Earth this way.

He has lots of other 3D images he’s made (I’ve linked to his incredible Apollo pictures before), including some amazing ones of icicles and such, at that link. If you have the 3D glasses it’s really worth perusing them.

Yesterday I posted a video showing a cluster of sunspots forming on the Sun’s surface. As it happens, a new video was released last night from NASA’s Solar Dynamics Observatory satellite showing this same sunspot group, but this time, along with the visible light images, we also get X-ray images. X-rays are emitted by plasma trapped in magnetic fields, so in a sense you can actually see the magnetism of the sunspots as they evolve. Watch!

How awesome is that? The full disk picture on the left combines visible and X-ray light, the lower right shows the spots in just visible light, and the upper right is just X-rays. You can see the magnetic field lines looping from one part of the sunspot cluster to another as the plasma follows them. If you look carefully, you’ll see flashes of brightness, too: those are solar flares!

The magnetic field stores energy. If the loops get tangled together, they can snap and release their energy in one sudden burst (like a box full of mousetraps, if you happened to see my episode of "Bad Universe" on Discovery Channel yesterday). What’s interesting about this video is that it shows that the rotation of the sunspots plays into this too.

Imagine a bunch of magnetic field lines coming from a spot, going up above the Sun’s surface, then back down to another spot. If the spot is rotating, that cluster of loops will get twisted up, just like a rubber band gets twisted when you rotate one end (do you kids these days still play with balsa wood airplanes that use a rubber band to spin the propeller? It’s just like that).

If the loops get too twisted, they’ll snap, too, and kablam! Solar flare. Remember, this was the biggest flare seen in several years, so apparently having several rotating spots feeding into the system really pumps a lot of energy into the loops. That makes sense, and it means that clusters of spots may be the ones we should keep our eyes on if we want to catch big flares in the act.

Video credit: Movie produced by D. Brown (UCLan). Data courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.

For the TL;DR crowd: an artist buddy of mine has drawn the cartoon print seen here, and is auctioning it off on eBay.

OK, now the details:

My buddy Len Peralta — the fantastic comic artist of Geek A Week and w00tstock fame — has started a fun new series of drawings called 50vs50. The "50" refers to 50 heroes and 50 villains, and he’s selling them. Literally.

You submit the name and characteristics of said heroes and/or villains, and, for a fee, he’ll draw them for you and send you a signed print.

I found out about this when Google Alerts notified me of the drawing here entitled, simply, The Astronomer. The noble pate, the steely determination, the ability to manipulate black holes… the resemblance to that guy I see in the mirror when I shave was striking. And sure enough, Len told me he based it on me.

Me, a hero. Awesome. I love Len.

Anyway, Len is doing this to raise money so he can go to San Diego Comic Con this year; he was accepted to attend as an industry professional, which is very cool. 50vs50 is his way to raise cash and have fun doing it.

Len and I then hatched a plan: He printed a second copy of The Astronomer, sent it to me, and I’ve signed it. I have it right here on my desk, in fact. Do you want it? Then bid on it! Len has put it up for auction on eBay. I’ll send it to the winner from BA HQ here in Boulder. And what the heck, I’ll throw in a few miscellaneous spacey items I have lying around here, too.

The auction runs through Saturday, April 23, and ends at 7:30 a.m. PDT (14:30 UT). Get bidding!

Ever wanted to see how sunspots form and change as they grow? The folks working with NASA’s SDO satellite just released this amazing video of the adorable younglings.

Not much happens until about 18 seconds in, and then a lot happens.

That is so freaking cool. Taken over the course of two weeks (half a rotation of the Sun), you can see them pop up, darken, and grow, and even rotate a bit as the Sun’s complex magnetic fields change… and the neatest part to me is the foreshortening they undergo as they approach the east side of the Sun’s disk. Amazing!

Sunspots are actually regions of slightly cooler material at the Sun’s surface. Hot plasma (ionized gas, stripped of one electron or more) rises from the solar interior, reaches the surface, cools off, and sinks back down. This is called convection, and is the same process you see in a pot of boiling water. But at the surface, the tortured and twisted magnetic field of the Sun can suppress convection, preventing the cooler material from sinking. Since the brightness of the plasma depends on the temperature, this cooler stuff is darker. Boom! Sunspot.

Or, in this case, sunspots. You can see five of the suckers here, changing and mutating as the plasma interacts with the magnetic field. I recognize these spots, too: they were responsible for the first X-class flare of the season on March 15th. There’s dramatic footage of that as well which I posted on my blog at the time. They’re busy spots; they blew out a lower energy flare a few days earlier, too.

And here I am calling them cute and little when they’re actually comfortably bigger than the Earth and exploded with the energy equivalent of millions — millions! — of nuclear bombs.

Good thing they’re 150 million kilometers away. That lessens the impact, but doesn’t negate it. The more we learn about the way sunspots behave, the better. SDO, STEREO, and the rest of our sunward-looking fleet are teaching us a lot about our nearest star. And we’ll need that information as we enter the beginning of yet another solar cycle.

Video credit: NASA/SDO

Most of the time, so-called "alternative medicine" is treated very gently by television news. I don’t know if that’s because they don’t want to tick off their viewers, or the reporters don’t look into it properly, or if they believe in it themselves. But no matter the reason, it’s always refreshing to see a show really tear into something like homeopathy. That’s precisely what the Australian program "Today Tonight" did recently:

The report featured such noted skeptics as Simon Singh, Richard Saunders, and James Randi, and made it very clear that homeopathy is just very expensive nonsense. I’m glad they didn’t make the report "balanced" by giving a lot of time to promoters of homeopathy; that’s not balance any more than giving time to someone who believes in storks delivering babies in a segment about infant health care.

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I’ve been posting some amazing time lapse videos of the night sky here lately, and I’ve been trying to set the bar pretty high. I like all the ones I’ve seen, but they have to have something special, something that sets them apart, for me to embed them here.

This one does just that. Earlier this month, photographer Terje Sorgjerd went to Mt. Teide in the Canary Islands to photograph the sky. He was upset when a Saharan sandstorm blew across the sky, ruining his video… or so he thought. What really happened was magic. Pay attention 30 seconds in to see the stunning results^*:

Simply breathtaking. The dust blows overhead, glowing golden as it’s illuminated from below by city lights, while above and beyond the Milky Way itself ponderously looms into view.

As the galaxy shows itself, look at the dark lane bisecting it. Feathery and ethereal, those dark fingers and tendrils are actually vast complexes of dust, long chains of carbon-based molecules floating in between the stars. Created when stars are born, age, and die, this dust litters the plane of the galaxy. Seen edge-on, it absorbs and blocks the light from stars behind it, creating the dark fog cutting across the breadth of our spiral galaxy.

There’s a poetry here; dust from a local storm blowing a few kilometers above, but translucent enough to allow us to see beyond it to a different kind of dust blowing among the stars.

Tip o’ the lens cap to Terje himself, who posts on reddit.

^* If the embed or link doesn’t work for you, Terje also uploaded it to YouTube. Make sure you set the resolution to 720p to get the full experience!

You know what you don’t get enough of? Hearing me blather on about astronomy and skepticism on a Sunday. So you’re in luck: I’ll be doing two interviews on Sunday:

1) At 6:00 p.m. Eastern (US) time (22:00 UT) I’ll be on Star Talk Radio with my old pal and all around cool dude Neil deGrasse Tyson, and my new pal, comedian and all around cool chick Leighann Lord (we’re the three on the left of that pic with producers Helen Matsos and Leslie Mullen on the right). We’ll be dissecting the science in science fiction movies and basically having a good time with it. You can listen to the show when it airs, but keep in mind we pre-recorded it when I was in NYC last week for NECSS.

What I will do, though, is listen along when it airs Sunday, and then I’ll be on Twitter making dumb jokes and snarky comments as usual. So join me there and I’ll answer your questions if I can.

2) I’ll be on the Think Atheist radio/podcast at 8:00 Eastern (US) time (midnight UT), and this one is live! So you can call in and ask questions. If you need more info, a pink unicorn will help:

So there you go. Mark your calendar! Twice!