- Latest image of the far side of the Sun based on high resolution STEREO data, taken on February 2, 2011 at 23:56 UT when there was still a small gap between the STEREO Ahead and Behind data. This gap will start to close on February 6, 2011, when the spacecraft achieve 180 degree separation, and will completely close over the next several days. Credit: NASA
Note to WUWT readers, as soon as this new imagery is made regularly available, it will be posted on the WUWT Solar Images and Data Resources Page
From NASA: It’s official: The sun is a sphere.
On Feb. 6th, NASA’s twin STEREO probes moved into position on opposite sides of the sun, and they are now beaming back uninterrupted images of the entire star—front and back.
“For the first time ever, we can watch solar activity in its full 3-dimensional glory,” says Angelos Vourlidas, a member of the STEREO science team at the Naval Research Lab in Washington, DC.
NASA released a ‘first light’ 3D movie on, naturally, Super Bowl Sunday:
| › Download this and more STEREO 360 videos
The solar sphere as observed by STEREO and the Solar Dynamics Observatory on January 31, 2011. Because the STEREO separation was still slightly less than 180o at that time, a narrow gap on the far side of the Sun has been interpolated to simulate the full 360o view. The gap and quality of farside imaging will improve even more in the days and weeks ahead. |
“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.”
Each STEREO probe photographs half of the star and beams the images to Earth. Researchers combine the two views to create a sphere. These aren’t just regular pictures, however. STEREO’s telescopes are tuned to four wavelengths of extreme ultraviolet radiation selected to trace key aspects of solar activity such as flares, tsunamis and magnetic filaments. Nothing escapes their attention.
An artist’s concept of STEREO surrounding the sun. Credit: NASA “With data like these, we can fly around the sun to see what’s happening over the horizon—without ever leaving our desks,” says STEREO program scientist Lika Guhathakurta at NASA headquarters. “I expect great advances in theoretical solar physics and space weather forecasting.”
Consider the following: In the past, an active sunspot could emerge on the far side of the sun completely hidden from Earth. Then, the sun’s rotation could turn that region toward our planet, spitting flares and clouds of plasma, with little warning.
“Not anymore,” says Bill Murtagh, a senior forecaster at NOAA’s Space Weather Prediction Center in Boulder, Colorado. “Farside active regions can no longer take us by surprise. Thanks to STEREO, we know they’re coming.”
NOAA is already using 3D STEREO models of CMEs (billion-ton clouds of plasma ejected by the sun) to improve space weather forecasts for airlines, power companies, satellite operators, and other customers. The full sun view should improve those forecasts even more.
| › See STEREO 360 videos
Observing solar storms from two points of view has allowed forecasters to made 3D models of advancing coronal mass ejections (CMEs), improving predictions of Earth impacts. Credit: NOAA/SWPC |
The forecasting benefits aren’t limited to Earth.
“With this nice global model, we can now track solar storms heading toward other planets, too,” points out Guhathakurta. “This is important for NASA missions to Mercury, Mars, asteroids … you name it.”
An artist’s concept of STEREO spacecraft. Credit: NASA NASA has been building toward this moment since Oct. 2006 when the STEREO probes left Earth, split up, and headed for positions on opposite sides of the sun (movie). Feb. 6, 2011, was the date of “opposition”—i.e., when STEREO-A and -B were 180 degrees apart, each looking down on a different hemisphere. NASA’s Earth-orbiting Solar Dynamics Observatory is also monitoring the sun 24/7. Working together, the STEREO-SDO fleet should be able to image the entire globe for the next 8 years.
The new view could reveal connections previously overlooked. For instance, researchers have long suspected that solar activity can “go global,” with eruptions on opposite sides of the sun triggering and feeding off of one another. Now they can actually study the phenomenon. The Great Eruption of August 2010 engulfed about 2/3rd of the stellar surface with dozens of mutually interacting flares, shock waves, and reverberating filaments. Much of the action was hidden from Earth, but plainly visible to the STEREO-SDO fleet.
“There are many fundamental puzzles underlying solar activity,” says Vourlidas. “By monitoring the whole sun, we can find missing pieces.”
Researchers say these first-look whole sun images are just a hint of what’s to come. Movies with even higher resolution and more action will be released in the days and weeks ahead as more data are processed. Stay tuned!
Related Links:
For more information about STEREO, please visit › www.nasa.gov/stereo.
› Download a self-guided Science Briefing explaining this historic “First”.
Dr. Tony Phillips
NASA’s Heliophysics News Team
Looks useful. Will help in getting earlier warning of the huge solar storms we are supposed to be enduring in the next few years.
Excellent. The more we learn about our star, the quicker we can debunk the CO2 myth.
As is the case with any proper football!
Alan Bates (UK)
Now we will be able to get a real sun spot total and perhaps get some idea as to what those magnetic fields are up to.
I got one of those:
http://www.robertb.darkhorizons.org/SDO_latest.jpg
It’s STEREO AHEAD 02-04-11 / SDO 02-06-11 / STEREO BEHIND 02-04-11
in composite Extreme Ultraviolet color.
Currently, the STEREO EUVI images are only available processed to full 2048×2048 resolution to the 4th of February (2-3 day lag).
In 2 days, I will have the first false-color image of the full Sun from Left/Center/Right.
What a sad end for an agency that once specialized in science and discovery. Now they’re harboring [snip] Hansen, and showing off a poor-looking “new” way of viewing a phenomenon that we’ve been viewing quite adequately for 400 years. Sort of like the Soviets in the ’50s showing off the Skoda and Trabant as great automotive advances.
Finally, the Dark Side.
John Marshall says:
February 7, 2011 at 1:38 am
While STEREO does not have continuum images to see the sunspots behind the line-of-sight, we can see the Active Regions in Extreme Ultraviolet. What is it really doing back there? Same thing it’s been doing in plain view: goofing off.
I’m feeling pedantic.
1 – Polistra – RTFA (Read The Fine Article). We have not, for the last 400 years been able to see both sides of the sun at the same time. It is a big deal … unless, of course, you think you already know everything there is to know about solar dynamics.
2 – “This gap will start to close on February 6, 2011, when the spacecraft achieve 180 degree separation, and will completely close over the next several days.” In theory, that’s not true. As long as a camera is a finite distance from the sun, it will never be able to see a complete hemisphere. OK, so that’s a quibble but the resolution drops off dramatically at the edges of the image. This is quite visible on the composite image above. The practical question is, how much does it matter. Right now, it doesn’t matter too much. If they find something new and important though, we could find more satellites in orbit around the sun.
This is going to double the sunspot count.
Implications for the sunspot counting method (all or only the earth’s visible?).
Implications for the ‘left-right limb imbalance’ theory for the new sunspot appearances.
No, it won’t, even if we wanted to. Remember that these STEREO birds have imagers that operate only in the extreme ultra-violet (EUV, 195 Angstroms). Sunspots are phenomena that can only be seen in visible light. What we see in EUV are the active regions, which of course include all of the regions bearing visible spots. But we can’t tell which regions have these visible spots until the sun rotates those regions towards Earth again. (Solar rotation period = ~27 days).
Sunspots are those highly magnetic portions of the active regions, where the magnetic field intensity exceeds 1500 Gauss. (Read the L&P discussions elsewhere on this blog to learn more about this).
BTW, this is really “old” news. STEREO has been showing most of the sun’s surface for a year or so. It’s just that the “hidden gap” is approaching zero width. But that gap has been so narrow in the last year, that it has had little or no impact on observing the far side. (Big regions tend to change slowly, just wait a day or so to see what was hidden etc.)
commieBob’s second point is very well made. This is wonderful, but I, too, can’t stop myself thinking that it would have been better if they’d put the two craft 12o° apart and 120° from Earth to give more consistent coverage (in conjunction with a nice, shiny new SOHO replacement somewhere around our home rock, maybe). Next time, perhaps – but I’m sure we’ll all enjoy watching what comes back from STEREO for now.
A sphere or an oblate spheroid? It seems to me that if the sun is rotating, then it’s more likely to be an oblate spheroid where the equatorial radius is greater than the polar radius. Of course I could be wrong. There seems to be a whole lot of interesting stuff happening with the sun. 🙂
@Steve C
> This is wonderful, but I, too, can’t stop myself thinking that
> it would have been better if they’d put the two craft 12o° apart and 120°
> from Earth to give more consistent coverage …
Your wish will come true before 2013. The two spacecraft are still drifting away from Earth, and will “meet”, opposite the Earth, around 2015. (No, they won’t crash because they’re on opposite sides of Earth’s orbit).
To see this just look at the figure at the top of this post!
I do hope the solar grand minimum doesn’t conflict with their instrument choices on stereo. I suspect they didn’t plan on having few major CMEs for the 8 years they’re useful.
Layman’s Sunspot Count has 9 spotless days this year.
Space Weather’s count stands at 1 spotless day in 2011.
The Grand Gore Minimum is upon us.
@John Day – You’re right, of course … my main irritation is that they can’t fire up some braking jets now and actually stabilise them at ±120°. (Really, I’d like to see one ‘above’ and one ‘below’ as well, if it weren’t for the fun you’d have trying to keep them there!)
It’s still going to be nice watching the ‘vids’ from these, though.
Whew! It’s a relief to verify there is no Romulan base on the far side.
@Steve C
> … my main irritation is that they can’t fire up some braking jets now and
> actually stabilise them at ±120° …
That would require too much fuel, I think, to be practical. Much less fuel would be needed at the Langrangian points, but you would still have hidden regions:
http://en.wikipedia.org/wiki/Lagrangian_point
My guess is that they decided to let them roam free to save money and to have a chance to see ‘everything’.
Best approach would be to have a fleet of solar orbiters, including a few in polar orbits to get some answers on the not-so-well-understood polar magnetic fields.
How is this being billed as 3D ?
You can not build a 3d image from two diametrically opposed viewpoints.
To have even some measure of depth (which is whole different ballgame from a 3D image) you need two different views of the same part of an object. What “Stereo” does is give two totally separate images with NO overlap.
Also the gap will never be zero because light leaving the dividing line , even tangentially will miss both spacecraft.
Animals such as humans have stereoscopic vision because they have two forward facing eyes. This allows an estimation of distance of an object but does NOT give a 3D image. Goats and sheep on the other hand have a wider field of view but lack stereoscopic vision over most of the field of view because the eyes are on opposite sides of the head.
“For the first time ever, we can watch solar activity in its full 3-dimensional glory,” says Angelos Vourlidas, a member of the STEREO science team at the Naval Research Lab in Washington, DC.
Well Angelo needs to go back to school and find out what 3D means.
This is nothing more than a more complete 2D image, in no way is it 3D. It’s not even stereoscopic now they are in opposing positions!
Amazin how NASA seems to adept at getting the basics wrong.
Schadow says:
February 7, 2011 at 7:10 am
Whew! It’s a relief to verify there is no Romulan base on the far side.
No, the Romulans have their bases on the back side of the Moon , silly.
Ever wondered why we now have the Sun, at 93 million miles away, in Panorama-Technicolor but still can’t see the back of the Moon?
Odd that…
“P. Solar says:
February 7, 2011 at 8:05 am”
Personally I agree with you and your post included many of my questions about this. At least we have a bigger picture to confuse things with.
@P. Solar
> Amazin how NASA seems to adept at getting the basics wrong.
No, it’s amazing how many of you didn’t bother to read the fine article (and relevant links). STEREO has obviously progressed beyond the ‘stereo-3D’, but earlier in its career it did snag some impressive 3-D imagery, which you can find on the STEREO website.
Now its mission has effectively changed from producing 3-D images to producing panoramas of the entire solar surface.
Maybe you owe NASA an apology?