First-ever images of the entire Sun | Hacker News Reader

First-ever images of the entire Sun

nasa.gov

70 pointsgeuis22 comments

"This is a big moment in solar physics," says Vourlidas. "STEREO has revealed the sun as it really is--a sphere of hot plasma and intricately woven magnetic fields."

Is it just me, or does that sound suspiciously like it is from an Onion article? I mean, it's very cool (and presumably useful) to have a full-time 360 view of the sun. But I'm pretty sure the idea the sun is a sphere of hot plasma is not startlingly new information...

How about the first sentence from the press release:

    "It's official: The sun is a sphere."

Besides; everyone knows that the sun is a mass of incandescent gas. (A gigantic nuclear furnace.)

Actually, it's a miasma of incandescent plasma (http://www.youtube.com/watch?v=sLkGSV9WDMA).

The point is, for the first time in human history, we can see by direct observation that the sun is in fact a sphere. It's not huge in the sense that "We were right!", but rather that wow... now we can actually see it!

I suppose that depends on your definition of "direct".

I was sad at how low-res and JPG'y the images were.

I wish NASA would release versions in whatever the native dimensions/resolutions they are receiving the image data back in.

Don't vote him down, that's a valid point. Much NASA data is made public, but it might not be linked from this particular site. I would recommend looking around and seeing if you can't find it.

You do not really want the raw data (it generally looks something like this[1], from the COR telescope, "FITS" format[2]. Warning: mix of ascii and binary). Anyway, this[3] links to where they are putting the raw and first-order-derived mission data they have released so far (if you want more of what you saw, you probably want SECCHI). And here[4] is an example of said derived data. And this[5] seems to be where they seem to be putting highlighted derived products for public outreach.

Generally, there is very little money and little expertise for polished public outreach efforts (they are scientists, not web developers, after all). There is a good chance the scientists behind [3] are doing some of it in their "spare" time. Feel free to drop them an email and let them know it is appreciated :)

1) http://sharpp.nrl.navy.mil//postflight/lz/L0/a/seq/cor1/2011...

2) http://fits.gsfc.nasa.gov/

3) http://stereo-ssc.nascom.nasa.gov/data.shtml

4) http://cdaw.gsfc.nasa.gov/movie/make_javamovie.php?img1=stb_...)

5) http://stereo.gsfc.nasa.gov/gallery/gallery.shtml

The image in the article is also not really low-res. As far as I can see Stereo’s CCDs have a resolution of 2048x2048, the image in the press release is 1280x720, that’s not exactly a substantial reduction (also considering that the two images from the two spacecraft were heavily distorted to create this side-view of the sun).

By the way, I found this wiki about processing and analyzing SECCHI’s images, if you wanted to you could presumably learn about it and start processing images on your own: http://secchi.nrl.navy.mil/wiki/pmwiki.php?n=Main.DataProces...

If you install CFITSIO[1], you can rebuild GDAL with FITS support. GDAL is the crazy-format swiss army knife. Some caveats[2] apply, though.

1) http://heasarc.gsfc.nasa.gov/docs/software/fitsio/fitsio.htm...

2) http://www.gdal.org/frmt_various.html#FITS

Step one to our very own Dyson Sphere ...

Next step is a Ringworld?

Am I the only one who sees this and wonders why there's such a large discrepancy between the right and left halves? Were they taken days / weeks / months apart or something? It kind of defeats the point of "stereo" to do so.

Specifically, why is that white splotch in such a radically different location (remember, diameter of the sun as Google states it is 1,391,000 km, that's gotta be near 100,000 km difference).

I read this article this morning. I wonder why they didn't launch one satellite into Orbit A, wait 6 months[1], then launch the second satellite into Orbit A, but from the other side of the sun. Then, once they maneuvered into position, we'd have satellites stationed on both sides permanently.

It seems like that would be a lot faster, and would also ensure we can maintain our full view of the sun for a long period of time.

[1]Or however long it would take to get to the opposite side of the sun, accounting for the first satellite's movements.

The stereos aren't staying in place, they start in the same orbit as Earth (and thus, with the same orbital speed). So we need to gently speed them up and slow them down. It would be inefficient to have the first probe burn a lot of fuel to stop, burn some fuel so it won't get pulled into the sun, and then 6 months later burn some fuel to resume orbit.

What he's saying is gently slow one down, then six months later gently slow down another. Then there will always be two opposing sats.

Only reason I can think of is that there is either other experiments on-board that they need to recover (solar wind collectors, etc), or that they were both taken up in the same launch vehicle, which would be the lion's share of the expense of this experiment.

Nope, you're not understanding the issue.

If you launch the first sat into Orbit A, it still has the orbital velocity of the Earth. Unless you can slow the first sat down a lot, it will continue to track along in about the same place as the Earth.

Waiting 6 months will accomplish very little in that case. The reason is, in 6 months, the Earth and the first sat will be in nearly the same place.

The key concept is known as "delta-v" (http://en.wikipedia.org/wiki/Delta-v). It's the change-in-velocity allowed by a certain amount of fuel. Here's some more on the STEREO mission trajectory: http://stereo.gsfc.nasa.gov/orbit.shtml It's worth it to watch the movie.

Gravity assist can help a lot, but it also takes a lot of time.

Agreed. I missed it. You'd probably have to wait something like 8 years for a long-term solution. With American ADD, wouldn't count on it actually happening.

Also, the people who design the missions eventually get old and retire. At some point, they have to take the human time scale into account.

Humanity Accomplishment: Dyson sphere sensor.

Next: Dyson sphere itself?

I actually debated posting this earlier today and decided against it (wasn't sure it was HN-appropriate). I'm a newbie so I'm learning every day.

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