Thursday, December 20, 2012

Holiday Greetings from the SDO Team

Happy Holidays from the SDO Team. Thanks for making SDO images appear all around the globe. From looking at comets to the Transit of Venus, we are glad the data is so useful.

The past year has seen an explosion in the science output of SDO! We look forward to many more years of studying the Sun's magnetic field.

We also made the cover of Jan/Feb 2013 issue of Discovery magazine. Look for it!

Monday, December 17, 2012

One Year Since Comet Lovejoy's Perihelion

It has been one year since Comet Lovejoy was watched by SDO, STEREO, and Hinode as it passed by the Sun. Each spacecraft provided unique observations we had not anticipated when they were built and launched. Hinode took an image of the coma in reflected sodium light. SDO and STEREO provided images in the EUV that we continue to analyze. Here is one picture from the movie comet_swoosh_171.mp4 on the SDO Comet Lovejoy Event Page. The streaks across the path of the comet have become the fascinating part of the comet tail.

In the past year we have figured out one way the comet tail can be bright in the solar corona. (Check out the paper at the Physics ArXiv site.) But we still don't know how the solar magnetic field affects (and is affected by) the comet as it moves through. All of that stuff coming off the comet makes the field shake, can we learn something from that? The brightness of the comet debris comes from running into electrons in the corona. Can we learn about the number of electrons in the corona?

We need even bigger sun-grazing comets!

Since Comet Lovejoy we have had only one alert to look for a comet in SDO and we saw nothing. But Comet ISON is due on Thanksgiving Day next year. It was acquired out near Jupiter, which usually means it is a big comet. As it moves toward the Sun, people are watching to see if stays bright. If it does we will be in for quite a show. Comet Lovejoy came in from the south and was seen only in the southern hemisphere. Comet ISON is coming in from the north and could be visible from the United States both inbound and outbound. Comet ISON will also pass through the corona a little farther out than did Comet Lovejoy, 1.2 million km (1.9 million miles) above the Sun's surface.

It would be like fireworks on Thanksgiving!

Tuesday, November 20, 2012

100 Million Images from SDO

The three science investigations of SDO have taken over 100 million images of the Sun. This corresponds to 3 Petabytes (3000 Terabytes) of raw, uncompressed data.

That's a lot of Dopplergrams, EUV images, magnetograms, and spectra of the Sun!

Congratulations to the science investigation teams for handling this data and making it available to solar scientists and the public.

Wednesday, November 7, 2012

Delta-H Maneuver Today

SDO executed a Delta-H maneuver today. The thrusters were fired for 33 seconds at 1751 UTC (1251 ET) to keep the reaction wheels spinning at the correct rates.

Tuesday, November 6, 2012

SDO in a Music Video, No Lunar Transit Next Week

There is a video on Youtube claiming that SDO will see a partial solar eclipse next week related to the total solar eclipse happening November 13. This is not correct. According to the SDO projections the Moon will not be closer than 2 degrees from the Sun next week.

SDO sees what we call that a lunar transit when it watches the Moon pass in front of the Sun. Lunar transits are important because of the campfire effect. What happens when you are feeling nice and toasty sitting by a campfire on a cold night and someone walks between you and the fire? You quickly feel cold! It is the same for our solar instruments. They are staring at the Sun and all of the sudden the Moon blocks some of the heat. We must use heaters to keep the instruments operating correctly. We plan quite far ahead for these transits.

No transit this month!

SDO images are included in a new performance called Unfolding Space by Yuval Avital. You can see the Trebuchet Prominence Eruption at 1:30 into the video. Some of the music is sonified HMI data provided by A. Kosovichev at Stanford University.

Wednesday, October 31, 2012

Monday, October 29, 2012

The SDO Website is Down

Due to anticipated power grid problems caused by Hurricane Sandy the SDO website has been shutdown. We regret the inconvenience. The website should return tomorrow. All SDO data is sent to the ground and stored at the data centers.

Current SDO images can be found at LMSAL's Sun Today website and the JSOC at Stanford. EVE data is available at the EVE space weather data page.
The level of solar and space weather activity is low and still being monitored by the GOES spacecraft. Check out their website at
Stay safe and dry; hopefully we will be back online soon.

Tuesday, October 23, 2012

AR 11598 Lets Go With an X1.8 Flare

Last night AR 11598 unleashed an X1.8 flare, reaching peak brightness at 10/23/2012 0322 UTC in AIA 94. This active region has produced quite a few flares since rotating into the view of SDO. With sunspot number currently at 86, perhaps even more active is at hand.

Monday, October 22, 2012

Data Handling Problems are Fixed

The data handling problems have been fixed and data is flowing normally.

Sunday, October 21, 2012

Some Images are Delayed

Due to problems at the SDO ground station some HMI data was not being transmitted correctly this weekend. Another anomaly at Stanford has introduced further problems. Once the computers are all fixed and talking to each other the data flow will return to normal.

Saturday, October 20, 2012

Bright Flare Today

We had a bright flare, exceeding an M5 today at 1815 UTC. It can be seen as the rise in the ESP 0.1-7 nm channel at the top of this plot. The active region that flared was on the approaching limb of the Sun.

Thursday, October 18, 2012

October 17, FOV and Flatfield Manevuers

SDO successfully wobbled around yesterday and completed the EVE field-of-view and AIA/HMI Flatfield maneuvers. Here is an example of an AIA 335 image during the maneuvers. You should notice that the CCD does not receive light in little segments near the corners of the image. These cutouts are caused by masks in the telescope that block the light and make a more or less round image region on the CCD. This was done because little light from the Sun goes to those parts of the detectors and we squeeze a little more bandwidth out of the telemetry downlink by knowing those triangles have no signal.

Tuesday, October 16, 2012

October 10, the EVE Cruciform Maneuver

Last Wednesday SDO performed an EVE Cruciform maneuver, where the spacecraft points up and down and then side to side. This allows the EVE scientist to track the calibration of the instrument and provide the accurate EUV spectral irradiances they are famous for. But it also causes some of the images from AIA and HMI to be blurred (such as this one in AIA 193).
Next maneuver is tomorrow, October 17, when we do the EVE field-of-view and HMI/AIA flatfield maneuvers.

Friday, October 5, 2012

Happy 130th Birthday, Dr. Robert H. Goddard

Robert H. Goddard, the inventor of the rockets that make spaceflight possible and the namesake of the Goddard Space Flight Center, was born this day in 1882. Goddard was born in Worcester, Massachusetts and grew up reading popular science fiction. He received patents for liquid-fueled and multi-stage rockets by 1914. While working at Clark University he used ballistic pendulua to show rockets worked in a vacuum and could be used to travel through space. Further work on rockets meant moving to New Mexico where the wide open spaces were a better place for testing.
Goddard's early work was ridiculed by the press. He once responded to a reporter's question with, "Every vision is a joke until the first man accomplishes it; once realized, it becomes commonplace."
When Goddard died on August 10, 1945 he held 214 patents involving rockets and rocket propulsion.
Happy Birthday Dr. Goddard. You left the world a more interesting place.

Wednesday, October 3, 2012

The First of the Fall Maneuvers is Today

Today at 1830 UTC (2:30 pm ET) we will perform the HMI roll maneuver. The images are usually oriented to solar north before we see them, but sometimes we get the watch the Sun appear to spin around. It keeps the instruments in good shape and allows the scientists to study the shape of the Sun. A recent article in Science magazine describes the surprising result that came from combining SDO and other measurements of the solar shape. The Sun is slightly oblate but less so than expected and without a change over the solar cycle.
More data is needed to understand why the Sun doesn't quite behave as we think it should.

Friday, September 28, 2012

Fall 2012 Eclipse Season Ends Tomorrow

The Fall 2012 SDO eclipse season ends tomorrow. Here is a look at the penultimate eclipse in the AIA 1600 bandpass. This wavelength of light is absorbed by the Schumann-Runge continuum of molecular oxygen at an altitude of about 110 km. This creates atomic oxygen, which moves upwards and creates the thermosphere. That atomic oxygen also is ionized by solar EUV to create the ionosphere.
At this wavelength the Sun looks like a ball with a thin, lacy network, bright active regions, and dark sunspots. Many of these features are a little above the visible surface of the Sun. They are held up by the solar magnetic fields. Welcome to the chromosphere, a layer of the solar atmosphere that will be studied by the Iris satellite. The people at LMSAL who built AIA and HMI are building Iris and hope to launch it in January.

Thursday, September 27, 2012

Station-Keeping Maneuver Successful!

Last night at 2250 UTC (6:50 pm ET) SDO performed another station keeping maneuver. These short firings of the thrusters keep SDO within the longitude box that defines its inclined geosynchronous orbit. The timing of the maneuver is chosen to affect as little of the science data feed as possible. This means it is often near dusk or dawn so that the velocity of SDO very nearly in the direction of the thrusters. We off-pointed only 1" (less than the size of the Sun) for this maneuver.
We are nearing the end of the Fall 2012 eclipse season on September 29. A few more partial eclipses and we will be seeing the Sun 24/7 until the Spring 2013 eclipse season!
As with any geosynchronous satellite, our ground station experiences radio interference (RFI) near the equinox when the spacecraft appears to pass close to the Sun in the sky. This is because the Sun is a source of radio noise that can overwhelm the signal we are listening to. This years RFI season has passed without loss of any data.

Wednesday, September 26, 2012

Website is Back, New Sun-Grazing Comet Seen Near Jupiter

The SDO website has returned to service.
A Russian observatory is announcing the discovery of the a new sun-grazing comet, this time out near Jupiter. Comet C/2012 S1 (ISON) will approach close to the Sun in November 2013, possibly as close as 0.012 AU (about 2 Rsun above the surface). It may become visible to the naked eye as well.
Comets become visible because they outgas water and other molecules, which reflect sunlight. The further from the Sun the comet becomes visible the bigger the comet usually is. Let's hope that we can get some nice data from SDO during the perihelion passage of Comet C/2012 S1 (ISON).

Power Outage of SDO Website

The SDO website will be down while a power line is run into the server room at Goddard. It should return to service later this morning.

Wednesday, September 19, 2012

A "Jovial" Transit of Venus

If you lived on Jupiter you would be able to see a transit of Venus tomorrow. It might look something like the one we saw in June. Here is an example in SDO AIA 171, a time-lapse still of the black disk of Venus moving across the Sun. Even though the transit can't be seen from Earth, the Hubble Space Telescope may be able to see the small decrease in sunlight reflected off Jupiter toward Earth during the transit. SDO will help by telling the scientists how the Sun's brightness changes during the transit. Given how quiet the Sun has been of late, that should be pretty easy for us to do. Jupiter is ahead of the Earth in its orbit around the Sun, so the quiet side is rotating to face Jupiter, even as a new active region rotates into the view of the Earth.
First contact is at 0456 UTC, mid-transit is 0953 UTC and 4th contact is 1451 UTC (all September 20 UTC). That means the transit at Jupiter lasts almost 10 hours (compared to about 7.5 hours for the June 2012 Venus transit at Earth).
It's all part of our search for Earth-like planets around other stars. We see a lot of planets in the Kepler data; how can we determine which ones have water and oxygen?

Thursday, September 13, 2012

SDO Image is Number 1 in SpaceShots

It is always nice to see an SDO image as the number 1 in a top 10 list. Fox News selected the "whip" filament as the top image in early September.

Thursday, September 6, 2012

Fall Eclipse Season has Begun

Today was the beginning of the Fall 2012 eclipse season. This image in AIA 171 shows that the Earth covered about half of the Sun this morning at 0700 UTC.
With the SDO geosynchronous orbit comes an eclipse season twice each year. They last for several weeks; this will end on September 26 (just in time for our next maneuver).

Wednesday, September 5, 2012

Images are Once Again Available

The database update at the JSOC has ended and data is once again flowing to the right places.

Tuesday, September 4, 2012

Temporary outage of browse data

The Stanford site is undergoing database maintenance mid-day on September 4. Unfortunately, browse data will not be available during this period.

Time for Prominences and Filaments

When I checked the kiosk movies today I saw that the edge of the Sun is ringed by prominences. And the face of the Sun is littered with filaments. If you check out the kiosk movie in the 304 band, you will an enormous eruption at 2 o'clock, quiescent prominences at 3, 5, and 7 o'clock, another eruption at 8 o'clock, and something interesting at 10 o'clock. With the 15-minute cadence of the kiosk you see flickering on the face as filaments erupt and move into space. A few small C-class flares happened over the weekend, but the prominence and filaments were the real show over the Labor Day weekend.

Saturday, September 1, 2012

Happy Space Weather Day!

Today is the 154th anniversary of the Carrington event. A large flare was observed on the Sun and a magnetic disturbance was seen to happen soon after. It was the largest space weather event ever observed.
To honor this observation, I think we should name September 1 as Space Weather Day!
For the more mathematically inclined, 154 is a sphenic number, a product of three distinct prime numbers (154 = 2 x 7 x 11). Other sphenic numbers are 30 (2 x 3 x 5) and 42 (2 x 3 x 7).

Monday, August 27, 2012

The Mantis Shrimp: A Miniature SDO?

SDO takes pictures of the Sun in many wavelengths and uses the polarization of the light to measure the magnetic field of the Sun. Then we are forced to rely on the human eye to look at our images. The human eye uses three color sensors to see millions of colors. We don’t see polarized light any different than non-polarized without special sunglasses. Polarized light has the light waves moving in one direction. Glare is light moving side-to-side so sunglasses that let light through that is moving up and down can keep glare out of your eyes. But we usually don't worry about polarized light.

Is there an eye that could better enjoy SDO images? Yes! The mantis shrimp.
These arthropods have up to 12 different color sensors and can see light from the ultraviolet to the infrared (see an amazing closeup of the eyes at the National Geographic.) Two channels see shapes and the rest look at colors. One set of eye cells can measure the polarization of the light. They can see about 10 times more colors over a wider range of wavelengths than humans.

Rather than the 3-color composites we now display (such as this one from today), we could display AIA and HMI images in a 12-color display. A mantis shrimp might enjoy watching for flares and coronal mass ejections!

We don’t understand why a mantis shrimp needs this optical equipment. They live in the brightly colored tropical oceans. Maybe they need to see the differences between friend, foe, and food. Some fish glow in ultraviolet light, perhaps that is another signal the shrimp watch for. The polarized light might reveal semi-transparent fish to a hungry mantis shrimp. Sounds like they have their own real-time feature finding team built into their eyes.

Perhaps we could adapt the multi-wavelength viewing used by the mantis shrimp to find out what is happening on the Sun.

Check out the July 30, 2012 episode of RadioLab to hear more about how different animals see color. 

Monday, August 20, 2012

A.C. Restored at Stanford, HMI & AIA Images are Flowing

The air conditioning at Stanford has been repaired and images are once again flowing to the right places. While the 48 hours of catchup is being played some images may be seen in the wrong order as a `latest' file. This is normal during the replay of the telemetry but the usual flow should be seen tomorrow morning.

Sunday, August 19, 2012

No A.C. at Stanford, HMI & AIA Images Not Available

Chilled water is still off at Stanford and HMI and AIA images remain unavailable. Best estimate is they will be available Monday afternoon.

Saturday, August 18, 2012

No A.C. at Stanford, HMI & AIA Images Not Available

Late last night the air conditioning at Stanford University stopped. HMI & AIA images will not be available until the problem is solved, possibly Monday. The science data is unaffected, but we do not have access to the computer drives that hold the images.

Thursday, August 16, 2012

SDO Images in a Music Video, Anniversary of Toronto Space Weather Event

Movies of erupting CMEs from SDO/AIA were used in the new music video by the band Dispatch - "Circles Around the Sun"! You can see the video here, which was filmed mostly at the VLA and uses a lot of historic NASA footage and movies of the aurora filmed from the ISS. Dispatch - Circles Around the Sun

Also, today is the anniversary of a small space weather outage in Canada. On August 16, 1989 the Toronto stock exchange was disabled by a geomagnetic storm. This followed on the massive outage in March 1989 that interrupted electrical distribution throughout Quebec. This geomagnetic storm was caused by a coronal mass ejection from a very large X20 solar flare seen on August 16, 1989, which was even stronger than the X15 flare on March 6, 1989 that heralded the earlier storm.
Microchips failed in August 1989 rather than the electrical grid. It affected many fewer people than the 6 million who were left without electricity in March. But it shows the many ways that space weather affects our society. What about the current solar cycle, #24? The Sun appears to have reached peak activity for Solar Cycle 24 in its northern hemisphere. The south continues to produce more and more sunspots. During the decline of a solar cycle the sunspots tend to last longer and the coronal mass ejections can cause large geomagnetic storms. Even though large flares are the heralds of violent space weather, it is the geomagnetic storms that interfere with power grids.
Solar Cycle 24 continues to follow the path of a below average cycle. It is also the best-studied solar cycle, with SDO, SoHO, both STEREO spacecraft, Hinode and numerous ground-based telescopes watching this cycle grow. We study the Sun to know when space weather happens and to learn how to predict it. The images from AIA and HMI are just the beginning of the science of SDO!

Tuesday, July 24, 2012

Maneuvers this Week

Wednesday at 1930 UTC (3:30 pm ET, 12:30 pm PT) SDO will perform a Delta-H maneuver. This is designed to keep the fine-guidance system within limits by using a series of short burns on the thrusters.
Thursday we will do two more maneuvers. The EVE Field-of-View maneuver will start at 1315 UTC (9:15 am ET) and the HMI/AIA Flatfield at 1630 UTC (12:30 pm ET).
Before, during, and after a maneuver SDO data may be unavailable.

Friday, July 13, 2012

A Busy Week for SDO

It has been a busy week for SDO. On Tuesday we did an EVE cruciform maneuver, where we point SDO back and forth and up and down to explore how EVE is working. At left is an AIA image taken during the cruciform.
On Wednesday the Hi-C rocket lifted off from White Sands Missile Range (just over the mountains from the SDO ground station) and took high-resolution images of the Sun. I haven't seen any images yet, but I'm sure they will look great!
Next, on Thursday we watched an X1.4 flare bloom out of AR 1520 (circled in the AIA 193 image at left.) The last X-class flare was from AR 1515 when it was near the limb (the right side of the Sun), so seeing one at disk center is pretty nice. We even got some news stories written about this flare:
With 2 X-class flares in 2 week it looks like the southern hemisphere is moving toward solar maximum!

Monday, July 9, 2012

SDO Shirts and Caps are On Sale

The SDO Apparel store has been temporarily re-opened. I'm not sure how long it will be open, so act quickly to purchase customized SDO shirts (see picture to left), caps, or backpacks. The store is a non-NASA website at
Please pass the information along to any interested people.

Sunday, July 8, 2012

Repairs are Complete and Site is Online

Thanks to Joe Gurman for installing the new RAID and moving the SDO website onto the new drives.
The Sun is looking beautiful today!

Saturday, July 7, 2012

SDO Data Site Under Repair, X-flare Erupts

The GSFC SDO website is having a disk replaced and should be back online tomorrow. Many thanks to Joe and Joe for installing the new drives. Repairs at the SDO ground station in New Mexico also delayed delivery of data to the SOCs in Palo Alto and Boulder. Both systems are repaired and delivery of the science data has resumed.
Of course, trouble with the data system means the Sun will do something interesting. An X1.1 flare erupted late yesterday (UT, 7 pm ET). Here is the EVE irradiances showing a peak in the top frame at 2300 UTC. The flare was in AR 11515, very close to the receding limb of the Sun, and in the southern hemisphere.

Friday, July 6, 2012

SDO Anomalies

The SDO RAID is undergoing a disk scan at this time. The web server is offline and will be until the scan completes. We have a new RAID out of the box and configured, so it might be ready to go by tomorrow. With a little luck, we'll be able to rsync it with the old RAID and get things back to normal soon.
Sorry for any inconvenience.

Saturday, June 30, 2012

Outages, outages, outages

Power outages caused by inclement inclement weather in the DC area are causing outages of many web servers and data services.  We apologize for any inconvenience. 

[UPDATE:  Power has been restored, but we expect some interruptions in services over the next couple of days as the SDO server undergoes maintenance.]

Friday, June 29, 2012

Computer Scans Occurring - Expect Temporary Outages

Our data server is undergoing scans and maintenance, so users may experience temporary outages and some data flows are being interrupted.  We apologize for any inconvenience.

Friday, June 22, 2012

EVE Rocket Launch scheduled for June 23

The next launch of the EVE underflight calibration sounding rocket payload is planned for June 23, 2012 at 13:00 MDT (window 13:00 - 13:30 MDT) (3:00pm EDT) from the White Sands Missile Range. This flight's primary purpose is to provide the third underflight calibration for the SDO EVE satellite instrument.  Good luck to the EVE time for another successful flight!  [UPDATE:  The launch and recovery went well, and all of the measurements appear to have been successful.  Congratulations!]
 See movies of the last EVE underflight

Where Have All the Sunspots Gone?

It is hard to believe we are in solar maximum when todays' sunspot number is 13 or 14. In this HMI continuum image we can see a tiny active region sitting isolated in the middle of the Sun. If it fades we will have a spotless Sun. The AR doesn't even have a number yet! But as the northern hemisphere fades from maximum, the southern hemisphere has still not reached solar maximum. If you look at an AIA 193 image you can clearly see the polar coronal hole is still open. We are still hopin' for some more fireworks from Solar Cycle 24.

Tuesday, June 19, 2012

Dynamic Trio

SDO is watching as a trio of large sunspots begins to rotate out of view (June 18-19, 2012) after spewing out numerous solar flares and coronal mass ejections.  The regions no longer appear to be growing, but it is likely that the decaying region will continue to produce eruptions for months to come.

Monday, June 18, 2012

New Picture of the Week

Twin M-class Solar Flares

Although visually it only looks like a single flare, sensitive scientific instruments indicated that these were actually two flares very close together (June 13, 2012) from Active Region 1504.  At 12:47 UT a M1.5 solar flare started and only five minutes later a M1.9 flare erupted from the same active region. The M1.5 flare peaked at 14:08 and ended at 15:00 UT. The M1.9 flare peaked at 14:35 and ended at 15:56 UT.  The image and video clips were taken in extreme ultraviolet light.  Indicators show that the coronal mass ejection associated with these flares might impact Earth a few days later.

Sunday, June 10, 2012

Venus Transit is Over, Site is Online

The Venus Transit ended early last Wednesday morning. Here is an image of Venus exiting the solar corona in AIA 193. Many thanks to the people who made the data display possible, especially to our Data Meister Phil Scherrer at Stanford University.
The website is a permanent source of images of the 2012 transit of Venus. Although it was briefly offline this weekend, we have re-enabled the website and you can once again look at the images and movies.
Next goal is a posting about how the diffraction pattern of AIA created the ghosts in the EUV images during the transit.

Tuesday, June 5, 2012

AIA Images Back to Normal

AIA images are back to normal on the SDO website.

AIA Images are Currently Unavailable

AIA images are having some problems with labeling. We are working to resolve the problem.

Monday, June 4, 2012

Venus Is In LASCO C2!

Venus is getting ever closer to the Sun as it moves towards tomorrows transit. Here is the view as it enters images from SoHO's LASCO C2 coronagraph. The type of science we will do with SDO during the transit is a story at the NASA SDO webpage.
SDO images of the transit will be available at our dedicated website.

Thursday, May 31, 2012

The Venus Transit is Getting Closer

You can see Venus just coming into view on the left of this LASCO image from May 31. Over the next 5 days Venus will approach and disappear behind the occulter disk. On June 5 we will watch Venus move across the Sun in the telescopes of SDO. Watch the SDO images at, starting at 2100 UTC (5 pm ET). The bright dot between Venus and the Sun is Mercury.

Wednesday, May 30, 2012

SDO Venus Transit Website is Looking Good

Next Tuesday SDO will witness a transit of Venus across the disk of the Sun. We will be producing a special set of data during the transit that allow us to check out the instruments on SDO, look at the Black Drop effect is several wavelengths, and see the atmosphere of Venus. AIA, the EUV telescopes on SDO, will see Venus against the corona about an hour before it touches the limb of the Sun.
We have started showing test data on the SDO Venus Transit website. There is no disk in the test data but you can see what the movies will look like. Use your imagination to see the disk! Then come back next Tuesday (June 5) at 2100 UTC (5 pm ET) to see the real transit.

Monday, May 28, 2012

AIA Images are Current

AIA images are now current at the SDO website. Many thanks to those who worked on the weekend to fix this problem.

Sunday, May 27, 2012

AIA Images are unavailable

Due to computer problems at Goddard, AIA images are not be updated at the SDO site. HMI and EVE images are current and AIA images are available at the AIA Science Team site.
The problem is being worked and we hope for a speedy return to normal.

Thursday, May 24, 2012

Venus Transit Testing Today

Starting at 1700 UTC (1 pm ET) today and lasting until 0300 UTC tomorrow (May 25, which is 11 pm ET May 24), we will be running a simulation of the observations to be taken during the Venus transit on June 5. AIA will be switching modes to take different sequences of images to allow the scientists to study the instrument and Venus. HMI will try out its transit mode as well but will return to normal operations after about an hour of special mode.
AIA will be taking three types of images during the test and transit. Every 96 seconds it will take a set of full-disk images. In between it will provide partial images (cropping out the southern polar region) at the usual cadences and striped images at extremely high cadences. Examples of these images are at left that were taken during a shorter test held May 23 between 1900 and 2015 UTC.
During the transit we will be providing movies of images taken during the transit at
Enjoy the show!

Tuesday, May 22, 2012

Temporary Interruption in browse data

There is a temporary interruption in the service of browse data on the SDO website. and are temporarily offline. We are working to get it back up as soon as possible.
Today, tomorrow, and Thursday we will be running tests of the Venus transit image sequences. During these tests the AIA images may be partial images or even striped images. These are designed to send data more suitable for studying the effects Venus will have on the data. Please be patient while we explore new ways to use the instrument.

Wednesday, May 16, 2012

Delta-H Maneuver Today at 1800 UTC

Today at 1800 UTC we will perform our 10th momentum management (Delta-H) maneuver. Data will unavailable from the SDO instruments from 1800 until 1824 UTC (2:00-2:24 pm ET) while the thrusters are fired to change the reaction wheel speeds. Reaction wheels are used to keep SDO very accurately pointed at the Sun. These burns keep the reaction wheels within their speed limits.

Tuesday, May 15, 2012

How Big are Today's Sunspots?

As we move through solar maximum in the solar north we can start comparing Solar Cycle 24 with other data. Here is a comparison of the active region 11476 in an HMI image from May 11, 2012 with the Earth (small dot) and Jupiter (big dot). AR 11476 covered about 1100 area units at its largest size. People claimed it was as big as Jupiter! We can see here that the dark core part of 11476 (called the umbra) was still quite small. Even though the entire sunspot was about half the size of Jupiter, it is mostly the dimmer penumbra.
Compare with the largest sunspot we have in a photograph, AR 14886 from April 7, 1947. We put the Earth and Jupiter disks in again and see that AR 14886 is larger (6000 units) than AR11476, still a little smaller than Jupiter (which is 10,000 units), and the dark umbra appears to occupy a larger fraction of the sunspot. (Original picture is courtesy of the Carnegie Institution of Washington.) One of the largest sunspot in Solar Cycle 23 was 10486, which caused the massive Halloween storms of 2003. It was 2600 units at its largest. The largest sunspots tend to occur after solar maximum and the larger sunspots tend to last longer as well. As we move through solar maximum in the northern hemisphere and look to the south to pick up the slack there should be plenty of sunspots to watch rotate by SDO.
CHECK IT OUT: SDO images are featured in the June issue of National Geographic!

Thursday, May 10, 2012

Still Active in the North, AR 11476 Flares Up!

The SWPC in Boulder issued a flare alert after an M-class flare in active region 11476. Here is an EVE plot from noon today showing the history of spectral irradiances. We usually look at the blue line in the top panel, the ESP 0.1-7 nm radiometer. It is very similar to the GOES X-ray measurements. The M-class flare is the spike in the blue line just after 0400 UT today. The dark count is a measure of the energetic particles hitting SDO and usually rises around 1800 UT each day because of the Earth's radiation belts.
Space Weather Message Code: ALTXMF
Serial Number: 170
Issue Time: 2012 May 10 0418 UTC

ALERT: X-Ray Flux exceeded M5
Threshold Reached: 2012 May 10 0417 UTC
NOAA Scale: R2 - Moderate

NOAA Space Weather Scale descriptions can be found at

Potential Impacts: Area of impact centered on sub-solar point on the sunlit side of Earth. Extent of blackout of HF (high frequency) radio communication dependent upon current X-ray Flux intensity. For real-time information on affected area and expected duration please see

Wednesday, May 9, 2012

Venus transit testing is over

The AIA Venus transit testing is over and images are flowing to the various archives.

Venus Transit Testing

Today at 1800 UT (2 pm ET) the AIA instrument started testing the instrument modes they will be using during the Venus transit on June 5-6. AIA images will be unavailable until the testing is complete (about 30 minutes). Some of the partial and striped images may be visible. There is nothing wrong with AIA and we will return to our normally scheduled pictures as soon as the testing is finished.

Friday, May 4, 2012

An Echo of a Lunar Transit

Some pictures from SDO go the long way 'round! Here is an AIA 304 image taken during the April 21, 2012 lunar transit and the same image sent to the moon, reflected back to the Earth and reconstructed by Daniela de Paulis back on Earth. I wonder if this is what the SDO images would look like if they were received by someone on Polaris? The striping in the lower image is visual static. It is what the hiss between radio stations would look like if you made it into a picture rather than listened. I do wonder why the noise has blue dots.
More information about sending images to the moon and back can be found the OPTICKS website.

Tuesday, May 1, 2012

SDO goes NOVA (at PBS)

The NOVA special Secrets of the Sun that ran Wednesday night is now available for streaming at the PBS website. You can still watch SDO data and scientists talking about the Sun and how it affects us. The stream at WGBH is only a preview.

Friday, April 27, 2012

SDO goes NOVA!

The NOVA special Secrets of the Sun ran Wednesday night, highlighting the SDO data and scientists. You can still watch it at WGBH. The SDO Weekly report for April 26, 2012 was pretty short: The FOT supported the lunar transit on 4/22. They also supported the monthly Atmospheric Imaging Assembly (AIA) Guide Telescope (GT) Calibration on 4/26.

Sunday, April 22, 2012

Lunar transit and Camilla on TV

Yesterday SDO had another lunar transit. Here is an example of this grazing transit.
Good Morning America will feature Camilla SDO and the crew that sent her into the stratosphere during a solar storm. This has already been reported on,, and I liked the movie of the balloon popping.
Check it out! Here is a link to the segment about the balloon launch.

Thursday, April 19, 2012

Maneuvers and Images

Last Wednesday and yesterday (April 11 and 18, 2012) we performed several spacecraft maneuvers to help calibrate our instruments. On April 4 we did an EVE cruciform and an AIA bakeout. This means the Sun moves back and forth and up and down. AIA images may be noisy (because the CCDs were warmed up to reduce contamination) and the Sun absent during this maneuver. HMI images may not show the Sun, or show it whizzing by as SDO moves.

On April 18 SDO did an EVE field of view and HMI flatfield maneuver.

While we do these maneuvers the data may be unavailable but by doing these maneuvers we keep the instruments healthy.

Thursday, April 5, 2012

SDO 360 degree roll

The Helioseismic and Magnetic Imager (HMI) instrument, one of three instruments on board NASA's Solar Dynamics Observatory (SDO), is making precise measurements of the solar limb to study the shape of the Sun.

Twice a year, the SDO spacecraft performs a 360 degree roll about the spacecraft-sun line. This roll maneuver allows us to remove the instrument optical distortions from the solar images taken by HMI to precisely determine the solar limb.

Thanks to the high resolution observations of the HMI instrument, solar scientist can measure if the Sun's sphere is changing over time as a result of the solar cycle. On April 4, 2012 SDO performed its 6th roll and the accumulated data is being studied and reviewed and will later be published in a paper.

4 April 2012 Roll Video

Wednesday, April 4, 2012

SDO Weekly Report for March 29, 2012

The FOT performed the SDO Station Keeping maneuver number 4 (SK4) on 3/28. We used 69 grams of propellant to keep SDO within our assigned box.

An HMI roll was performed this morning (April 4) starting at 0550 UTC.

AIA images are again current.

Monday, April 2, 2012

AIA Images are Delayed in Processing

AIA images in several channels are delayed in processing. They should be up-to-date soon.

Wednesday, March 28, 2012

Last Eclipse of the Spring Season

Today we had the last eclipse of the Spring 2012 Eclipse Season. Here are 4 images of the Sun at about 0630 UT today. Comparing the upper left image (1600) with the upper right and lower left we see the different ways the Earth's atmosphere absorbs light from the Sun. Ultraviolet light at 1600 Å is absorbed about 105 km above the surface of the Earth while 193 is absorbed at 130 km and 304 at 150 km. (171 is absorbed at 120 km). The 1600 edge is pretty straight while the others are rougher. Changes across the disk of the Sun are important in the other three channels, but the effects of changes in the Earth's atmosphere at 150 km can be seen at the top of the 304 image.

To really see the effects of the Earth's atmosphere you should use difference images. If all of the solar patterns can be determined you can map the Earth's thermosphere with these partial occultations.

Next on the schedule is a ΔV burn today at 2315 UTC (7:15 pm ET).

Tuesday, March 20, 2012

SDO Weekly Report for March 15, 2012

The FOT successfully performed SDO momentum unload maneuver #9 on 3/14. The firing of our thrusters for a few seconds is sufficient to keep our reaction wheels within safe speeds. (Here is a thruster being tested before launch.)

No comet was seen last week, either in AIA or emerging from perihelion in the various coronagraphs. Lovejoy continues as the only Kreutz comet to survive perihelion in the SOHO era. SDO is not in a good position to see Kreutz comets, they approach from behind and must survive perihelion to be visible. From June to December we will be in a better vantage point for seeing comets disintegrate in the solar corona.

Tuesday, March 13, 2012

Another Comet?

SOHO and STEREO are reporting another Kruetz comet moving toward the Sun. It is expected to make its closest approach to the Sun tomorrow, March 14. If it survives perihelion and is bright enough, we would see this comet appearing in the upper right side of the Sun and moving down over the disk. Current estimates are that this comet is smaller than Lovejoy. At this time we do not know the time of perihelion passage.

We have a daily eclipse of the Sun by the Earth (at 0630-0730 UTC tomorrow), and a momentum management burn tomorrow at from 1845-1915 UTC. During both periods the images of the Sun may be absent.

Monday, March 12, 2012

EVE CCD Bakeouts his Week

We will be baking out the MEGS CCDs this week starting Monday, March 12, 2012 at about 1400 UT. This will mean no science data from MEGS-A and MEGS-B during the warmup, bakeout, and recovery sometime Wednesday, March 14. ESP is not affected by the bakeout and will continue to produce science data.

Bakeouts are a normal and essential part of maintaining the accuracy and sensitivity of an on-orbit spectrometer. Even small amounts of contamination sitting on the chip can reduce the measured solar signal. Heating up the CCDs drives the contaminants off the CCDs and reduces the effect.

Thursday, March 8, 2012

Major Geomagnetic Storm Coming?

This morning major news organizations are reporting on the possible geomagnetic storm associated with the flares seen earlier this week.

Examples: BBC News, CBS News, and The Washington Post. Most use an SDO image to show the flare!

Wednesday, March 7, 2012

Another X-class Flare!

At 00:28 UTC this morning we saw another X-class flare from active region 11429. Here are pictures in 1700 (left) and 1600 (right) showing the two ribbons of this flare. This X5.4 flare lasted long enough to be easily seen in the browse image movies on the SDO website.

Tuesday, March 6, 2012

Eclipse Season Starts Today

March 6, 2012 marks the beginning of the SDO Spring Eclipse Season. For the next three weeks the Earth will pass between SDO and Sun at about midnight Boulder time. The length of the occultation will vary from short to almost 72 minutes. Thee eclipses are a normal part of life in a geosynchronous orbit.

The AIA data is currently stale (i.e., delayed) but the problem is being looked at.

Monday, March 5, 2012

X-class flare this morning

An X-class flare occurred in Active Region 11429 this morning at about 0400 UTC (or last night at 11:00 pm ET). Here is the EVE spaceweather feed showing the Sun brightening. Stayed tuned for more images!

Here is a picture of the X1.1 flare at 04:00:32 UT today. You can clearly see the two ribbons that form along the flare. This image is in light at a wavelength of 1700 Å, in the ultraviolet. It measures the response of the chromosphere rather the corona seen in the shorter wavelength channels.

Friday, March 2, 2012

The Think Scientifically Books are Out

The first two Think Scientifically books are available from SDO Educators Website. Each book focuses on a key science theme and includes a hands-on science lesson, math and language arts activities, and other educational resources that can be easily utilized in the classroom. The books are based on national standards and were written by teachers. Both books can be downloaded as pdf files from this website.

SDO began High Gain Antenna (HGA) handover season on February 23 and all handovers have been successful since then. The FOT is ready for the beginning of eclipse season on March 6. The next momentum unload maneuver in scheduled for March 14.

Wednesday, February 29, 2012

SDO Images are Delayed

There is a delay in processing the near-realtime images at LMSAL. They are aware of the problem and are working on resolving it. Some near-realtime images will be missing beginning around 0000 UT on 29 February 2012.

Saturday, February 25, 2012

AIA Images are now current

The power outages at the AIA offices have been fixed and the images are current.

Friday, February 24, 2012

AIA Images are Delayed in Processing

There is a processing delay at LMSAL, beginning at 0700 UTC on 24 February 2012.
The responsible people have been notified, and we are awaiting a reply.

Tuesday, February 21, 2012

Lunar Transit has Passed

Here is an image of the Sun as the Moon moves off the limb at 1427 UTC (0947 am ET) today. It was a fairly shallow transit, but the Moon covered a bright active region. This caused a dip in the EVE output and may allow scientists to calibrate the energy emitted by the active region.

Monday, February 20, 2012

Lunar transit on February 21, 2012

On Tuesday, February 21, 2012 we will again watch a lunar transit from SDO. Here is a video showing the path of the Moon as seen by the SDO instruments.

Saturday, February 11, 2012

SDO Second Anniversary

At 10:23 am ET on February 11, 2010 SDO rose into the sky atop an Atlas V booster. 108 minutes later we were a free-flying satellite! In the 2 years since we have taken about 70 million images of the Sun, in EUV wavelengths, Doppler and Zeeman filtergrams, and EUV spectra. We have seen late phases of flares, magnetic fields as they rise to the solar surface, and 2 comets. Enormous prominence eruptions have been a favorite, especially when the material brightens as it splashes back down onto the surface.

This year we will watch as Solar Cycle 24 approaches solar maximum, at least in the northern hemisphere. Venus will go across the face of the Sun on June 5-6. It will be another banner year of SDO data and science.

Happy Birthday SDO!

SDO is still GO!

Friday, February 10, 2012

Second Anniversary of the SDO Launch

As we come up on the second anniversary of the SDO launch on February 11, 2010, it is nice to look at what is happening with SDO data. Steele Hill, media specialist for SDO, has developed a set of prints from SDO (and a few other satellites) called The Sun as Art. You can see the images on the SDO website. But you can also go see them at the Maryland Science Center in downtown Baltimore.

Last nite Steele attended an reception to honor members of the Science Center as well as the opening of The Sun as Art exhibit. Here we see Steele and friend at that opening of The Sun as Art exhibit in Baltimore. It was nice to see the images of the Sun hanging in a science-friendly place! After 3 months in Baltimore the exhibit will travel to other science museums.

NASA has just released a study of the Snowmageddon storm that caused such angst during the SDO launch. You can read the story on the NASA Portal. The high winds caused a one-day delay in the launch and then the low temperatures allowed us to see the beautiful waves and disappearing sun dog on the 11th. But the Snowmageddon Team Launch stuck at Goddard got us into orbit and on our way to a great mission.

SDO is GO!

Thursday, February 9, 2012

SDO Featured on the IEEE Spectrum, 2.12

Check out whose on the cover of IEEE Spectrum 2.12! The story is on solar storms affecting the power grid. Space weather is becoming more interesting as we approach the maximum of Solar Cycle 24.

We are approaching the 2nd anniversary of SDO's launch on February 11, 2010. The satellite is still working great!

Sunday, February 5, 2012

An Uneventful Week

After AR 11402 left loose with several large flares and produced proton fluxes not seen since 2005. the Sun flatlined this past week. There are still cool things to look at, like when is the southern hemisphere going to catch up with the northern.

SDO images and scientists will be featured in NOVA's The Secrets of the Sun, coming to a Public TV station near you on April 25, 2012. Check out the PBS Homepage for more details.

Friday, January 27, 2012

Another Flare Under Way

Updated at 2:53 pm ET (1953 UTC). Even though the flare peaked and quickly subsided, the proton flux at GOES as risen substantially. Here is the GOES protons fluxes (different colors are different energies). A flare at the limb shouldn't produce a large increase in the proton flux, but this one did!

Another X-class flare is happening right now! AR 11402 has let loose with an X-class flare as it disappears over the limb. Here is the EVE flare watch page (on left) and the SWPC X-ray flux (right).

It's a great week for Space Weather!