Set the controls for the heart of the Sun

April 21, 2010 2:19 PM

"First Light" for the Solar Dynamics Observatory - researchers unveiled "First Light" images from NASA's Solar Dynamics Observatory, a space telescope designed to study the Sun.
posted by Burhanistan (42 comments total)

The mp4 files take a while to load, but the wait is totally worth it.
posted by Burhanistan at 2:22 PM on April 21, 2010

SDO on Flickr.
posted by homunculus at 2:26 PM on April 21, 2010 [1 favorite]

Interesting that they chose a geosynchronous orbit instead of parking it at a LaGrange point like SOHO. Implies that data transfer rates are more important than continuous observation, which I suppose is true if they're releasing huge video like this.
posted by richyoung at 2:27 PM on April 21, 2010

Were they trying to make the sun look evil? That greenish bluish false color image is just plain sinister, and the "erupting prominence" looks like an enormous pincer. Thanks a lot, NASA. Now I'm terrified of our star. Earth is apparently orbiting Cthulhu.
posted by aparrish at 2:35 PM on April 21, 2010 [1 favorite]

Oh my goodness, look at the prominence in the 1st, 2nd, and 5th pictures. You can clearly see that the ejected material is winding itself helically around an invisible, circular, (magnetic) field line.
posted by jamjam at 2:37 PM on April 21, 2010

Fuck.
posted by sexyrobot at 2:43 PM on April 21, 2010

*jaw drops*
posted by Guy_Inamonkeysuit at 2:45 PM on April 21, 2010

That first movie is gorgeous. Anyone know if it's in real time?
posted by Paragon at 2:50 PM on April 21, 2010

"Uploaded on April 21"? Where were photos like this yesterday?

Dude.
posted by Nothing... and like it at 2:52 PM on April 21, 2010

Interesting that they chose a geosynchronous orbit instead of parking it at a LaGrange point like SOHO.

From the looks of this video, the satellite is inclined enough that it will maintain a continuous view of the sun while in orbit. The mission page also says it'll have a nearly continuous view.
posted by borkencode at 2:53 PM on April 21, 2010

Absolutely incredible.
posted by loquacious at 3:00 PM on April 21, 2010

i was just looking at the pix from stereo of the massive eruptive prominence of april 13th last night...but this...wow!...can't wait to see sdo's observations of it (the TRACE website seems to be missing it's automated daily movies from that date, so it's probably a major part of someone's research right now...)

Interesting that they chose a geosynchronous orbit instead of parking it at a LaGrange point like SOHO. Implies that data transfer rates are more important than continuous observation, which I suppose is true if they're releasing huge video like this.

The rapid cadence and continuous coverage required for SDO observations led to placing the satellite into an inclined geosynchronous orbit. This allows for a nearly-continuous, high-data-rate, contact with a single, dedicated, ground station.
Nearly continuous observations of the Sun can be obtained from other orbits, such as low Earth orbit (LEO). If SDO were placed into an LEO it would be necessary to store large volumes of scientific data onboard until a downlink opportunity. The large data rate of SDO, along with the difficulties in managing a large on-board storage system, resulted in a requirement of continuous contact.
The disadvantges of this orbit include higher launch and orbit acquisition costs (relative to LEO) and eclipse (Earth shadow) seasons twice annually, During these 2-3 week eclipse periods, SDO will experience a daily interruption of solar observations. There will also be three lunar shadow events each year from this orbit.
This orbit is located on the outer reaches of the Earth's radiation belt where the radiation dose can be quite high. Additional shielding was added to the instruments and electronics to reduce the problems caused by exposure to radiation. Because this a a Space Weather effect, SDO is affected by the very processes it is designed to study!

...the site also mentions that they're capable of taking/downloading pictures every second(!) compared with every three minutes for STEREO and every 12 min for SOHO...wowza!
posted by sexyrobot at 3:05 PM on April 21, 2010 [2 favorites]

Beautiful. Thanks for posting this!
posted by snsranch at 3:06 PM on April 21, 2010

Once again I am reminded that I am a tiny blob on a little planet.

Science is cool. I wish more of my science teachers had actually been able to impart that sentiment.
posted by ambrosia at 3:14 PM on April 21, 2010

Appears to be a double helix, actually.
posted by jamjam at 3:25 PM on April 21, 2010

Besides being ridiculously awesome, I'm glad that this is also bringing more people around to the truth that the Sun is bloody terrifying.
The sheer scale of it combined with the incredible detail in these images is utterly dizzying. Just thinking about it makes me feel like I'm tipping over the top of a roller coaster backwards.

Can't sleep. Sun'll eat me. Can't sleep. Sun'll eat me.
posted by lucidium at 3:57 PM on April 21, 2010 [4 favorites]

Oh c'mon, you're like a baby. The sun is only about 100 times the diameter of the earth. What's so scary about a ball of hydrogen bombs 100 times the diameter of the earth that's been exploding for four-and-a-half billion years? YOU ARE LIKE A BABY!

[/Avatar]
posted by sexyrobot at 4:10 PM on April 21, 2010

I was curious to know how the heck they produce high-resolution images of magnetic fields without being inside them to sense them. A little searching lead to this page about magnetograms that explains a lot about these.

But the short version is that magnetic fields do things to the wavelength and polarization of light emitted by atoms within the field, and it's the effects on the light that can be sensed at high resolution and from a distance, not the magnetic field itself.
posted by FishBike at 5:16 PM on April 21, 2010 [2 favorites]

Holy hell, that IS unsettling. You guys weren't joking.

Are we... uh... are we supposed to be seeing this? I'm just saying...
posted by unixrat at 5:25 PM on April 21, 2010

Are we... uh... are we supposed to be seeing this?

I had sort of the same feeling when I read this part:

"We're processing the data now," says Scherrer, "and soon we expect to have some nice maps of the sun's interior."

If there is a supreme being, I imagine he/she/it being exasperated that apparently no mystery of the universe is safe any more. No peeking, you bastards!
posted by FishBike at 6:05 PM on April 21, 2010

My God, it's full of fusion!
posted by The Whelk at 6:23 PM on April 21, 2010

Earth is apparently orbiting Cthulhu.

The sun is clearly Unicron.
posted by regicide is good for you at 6:42 PM on April 21, 2010 [1 favorite]

My God, it's full of fusion!

Well, Wikipedia says:

The core is the only location in the Sun that produces an appreciable amount of heat through fusion; inside 24% of the Sun's radius, 99% of the power has been generated, and by 30% of the radius, fusion has stopped nearly entirely.

So, really, it's only about 1 or 2% fusion by volume. But a later paragraph is really surprising and not at all what I would have expected:

At the center of the sun, fusion power is estimated by model to be about 276.5 watts/m³, a power production density which more nearly approximates reptile metabolism than a thermonuclear bomb. Peak power production in the Sun has been compared to the volumetric heats generated in an active compost heap. The tremendous power output of the Sun is not due to its high power per volume, but instead due to its large size.

Let's just think of it as a giant high-temperature hydrogen compost heap, shall we? Or some sort of spherical fusion lizard.
posted by FishBike at 6:55 PM on April 21, 2010 [8 favorites]

I am so surprised we haven't seen this yet

INACCURATE IS ROCKER!
posted by The Whelk at 7:03 PM on April 21, 2010

Burhanistan: sorry about the load times - the underlying servers are running quite smoothly (We engineered the site with this kind of load in mind) but the content wasn't hinted for HTTP streaming so you have to download close to 30mb before it starts playing. I was talking with our content group about that earlier today - they were busy getting everything up in time as it was.
posted by adamsc at 7:57 PM on April 21, 2010 [2 favorites]

adamsc: wow, didn't know you were in on this. This is really just superlative stuff and has opened a door in everyone's apperception of the Sun. Thanks many times over!
posted by Burhanistan at 8:00 PM on April 21, 2010

(to everyone involved, of course)
posted by Burhanistan at 8:01 PM on April 21, 2010

Thanks definitely go to the hardworking SDO team well ahead of me - some Django code is cake compared to the actual cutting-edge science
posted by adamsc at 8:16 PM on April 21, 2010

Absolutely amazing images, but some of the false color schemes are weird. Red areas are cooler than blues and greens? A magenta sun? Is there a profound reason for the choices, or are astronomers just having fun with their favorite colors?

I haven't been able to watch the feature movie yet due to DSL suckage, but the short clips were pretty incredible. I may leave my laptop running overnight for this download. Watching the Sun's surface roil and flare, it seems cartoony-fake how fast things happen. My brain expects glowing red fluid to move like lava, slow and viscous, but this hydrogen gas stuff is light and quick. But it doesn't move like puffs of steam either - it writhes and coils before sinking back toward the surface. I guess "unearthly" is the perfect description, in all its connotations.

"First light" is a lovely evocative term for the first time a telescope opens its shutter and acquires data. Makes me think there's a poet in every astronomer.
posted by Quietgal at 8:57 PM on April 21, 2010

OK, it only took 5 or 10 minutes to load the movie. I'm puzzled by the way the flares appeared to vanish abruptly, though - both times, the plumes coiled up then burst like a bubble and began sinking back down, but suddenly vanished completely before hitting the surface. Is this real, or some kind of data sampling rate artifact? (Or a crappy download/slow computer?) Does anybody else see this or do I need a better internet connection?
posted by Quietgal at 9:25 PM on April 21, 2010

Incidentally, Spherical Fusion Lizard is the name of my new retro-jazz-rock band.
posted by Greg_Ace at 9:32 PM on April 21, 2010

oh metafilter...
posted by The Whelk at 10:13 PM on April 21, 2010

because, oh yes, a spherical fusion lizard 100 times the diameter of the earth isn't scary at all...

speaking of scary, here's a quick size comparison of the sun to some other stars...

Is there a profound reason for the choices, or are astronomers just having fun with their favorite colors?

not really, mostly just convention...typically, though, the color scheme in astronomical images involves spreading out the spectrum to cover more area. for example, red is often used to represent infrared, green for visible light, and blue for ultraviolet...but different spacecraft observe at different frequencies...usually red represents the 'cooler' area of the spectrum (longer wavelegnths) through blue for 'hotter', more energetic, shorter wavelengths (for example the numbers above the top row of pix here, on the SOHO current images page refer to the wavelength of the light (in nanometers)...you can see how the colors run...although these are all ultraviolet wavelengths) (looking at the instrument page on the SDO site, it appears that it images the sun in about ten UV and extreme UV wavelengths and one in visible light)...when you see the images of the sun where it's all sickly multicolored, that's because the different images are stacked, similar to the way images shot through red, green, and blue filters stack to make a natural color image.

it seems cartoony-fake how fast things happen.
well, these are considerably sped up...from hours into seconds...
posted by sexyrobot at 10:23 PM on April 21, 2010

Red areas are cooler than blues and greens...

The choice of color tables is actually a natural one. Physically, cooler bodies emit redder light, while hotter bodies emit bluer light. (For one example of this, think about stars: the coolest stars, stars like red giants, are red, while hotter ones, like supergiants are blue.) I'm not a big fan of the color tables used in these movies (the raw data are, of course, black and white while the color is added artificially) but that's why they're chosen and what they're trying to evoke.

I'm puzzled by the way the flares appeared to vanish abruptly

I'm not sure exactly which movie you're looking at, but regardless, this is real, not an artifact. You have to remember that when you look at any of this EUV imagery, you only see the plasma that happens to be visible to the particular channel of observation. Each channel is sensitive to the light emitted by plasma of a certain temperature. If the plasma is hotter or cooler than that temperature then the light it emits changes wavelength and it becomes invisible. Additionally, plasma that is the right temperature but the wrong density becomes essentially transparent to the cameras on SDO. On top of all that, you need a certain volume of plasma in order for it to show up, so a thin little feature might also be invisible and only when a few small features come together do you start to see something.

So when you see plasma disappear in these movies it doesn't mean that it's going away, but rather it is being heated or cooling up to the point that it cannot be seen in that particular channel. In fact, the corona (the sun's atmosphere that most of these images are of) is actually full of plasma, it's just that you only see a little bit of it in any particular image and wavelength.

By the way, assuming that something feature goes away because it disappears is an error I've seen more than one professional solar physicist make. Our perceptions are so ruled by the collected experiences of life on earth stored in our brains that it takes a long time to learn to interpret images like these correctly.

My brain expects glowing red fluid to move like lava, slow and viscous, but this hydrogen gas stuff is light and quick. But it doesn't move like puffs of steam either - it writhes and coils before sinking back toward the surface...

A few points about this. First is maybe the most obvious. The plasma you see here is not actually red (or yellow or blue). The color is artificially added. It's easy to be fooled, but the light it emits is invisible extreme-ultraviolet and the images are all actually black and white.

Second, these movies are not at all in real time. What you see is actually sped up from many hours of observation to a few seconds. The flow velocities are still high compared to earthly things, but not nearly as fast as they appear.

Finally, without going into detail, the plasma in the solar corona is in a special state that physicists refer to as "frozen-in." Basically, that means that the plasma and magnetic fields in the corona are bound together kind of like beads on an invisible wire. If you pull on a blob of plasma, the magnetic field is stretched along with it. If you move a magnetic field line, the plasma comes along. The plasma can freely move along magnetic field lines, but it cannot cross them.

That's why you don't see it just fall straight down, but rather flow in loops and coils. It's not free to go anywhere it wants. Once an eruption begins, cooling plasma begins to drain down the erupting field lines back to the surface under the force of the sun's gravity. Since it can't fall across field lines, it falls down along them, tracing out the hidden lines of magnetic force that permeate the corona.

(Disclaimer: I'm a solar physicist who works at an institution that is a European hub for SDO data, though I work on another space mission, not SDO itself.)
posted by dseaton at 10:57 PM on April 21, 2010 [7 favorites]

Oh, hey! Dean Pesnell gave a talk here back when SDO (was scheduled to be) launched. He was a postdoc of my current postdoc advisor. The breadth of his knowledge is incredible.
posted by dirigibleman at 11:09 PM on April 21, 2010

I'm sorry, apparently he was a grad student here (and my adviser was his thesis adviser? I don't even know, now).
posted by dirigibleman at 11:17 PM on April 21, 2010

The message from these movies & images is clear - the sun is evil, it is trying to kill us, and therefore must be destroyed.

Who's with me?
posted by kcds at 4:56 AM on April 22, 2010

The message from these movies & images is clear - the sun is evil, it is trying to kill us, and therefore must be destroyed.

We must attack at once!

("Do they think we are fools? We will land on the sun AT NIGHT!")
posted by FishBike at 5:40 AM on April 22, 2010 [1 favorite]

"We're processing the data now," says Scherrer, "and soon we expect to have some nice maps of the sun's interior."
If there is a supreme being, I imagine he/she/it being exasperated that apparently no mystery of the universe is safe any more. No peeking, you bastards!

Oh... you're going there? *Dungeon Master with furrowed brow hurriedly sketches out new room*
posted by Durn Bronzefist at 7:30 AM on April 22, 2010

Thank you, dseaton and sexyrobot, for the clarification. (Facepalm for my reading comprehension fail, though.) The color choice makes sense scientifically, but just try convincing a layman or artist that orange is cooler than blue!

The "disappearing" flares are in the star sorry movie, the top-front-center image of the first link. I guess I don't feel so dumb if professional astronomers occasionally forget about bandpass filter limits.

Dseaton, thanks again for the fantastic comment. It's wonderful that real live physicists hang out here and rub virtual shoulders with us lesser mortals. MetaFilter is the best!
posted by Quietgal at 8:57 AM on April 22, 2010

just try convincing a layman or artist that orange is cooler than blue!

just think of it as a Black-body radiator.
imagine a hot iron poker...first it glows red-hot, then orange, yellow, white, then blue-hot...
posted by sexyrobot at 9:56 AM on April 22, 2010

Wow, these pictures are great.
posted by dgaicun at 12:23 PM on April 22, 2010 [1 favorite]