Happy Summer Solstice and Congratulations to Phil Scherrer!

Today at 1554 UTC (11:54 a.m. ET) the Sun reached its most northerly point in the year. As a result, we have the most daylight hours in the northern hemisphere and the Southern Hemisphere has the most dark hours. At the solstice the Sun appears to stall and turn around, heading towards the south and northern winter. It's the official beginning of summer and all because the Earth's rotation axis is tilted 23° from the plane of its orbit. Here's an AIA 193 Å to celebrate.

But today is also a day to congratulate Phil Scherrer of Stanford University who is also the HMI PI and the person who watches over the JSOC with the HMI and AIA data. Dr. Scherrer was awarded the Solar Physics Division's Hale Prize last week at the 234th Meeting of the AAS. The Hale Prize is awarded annually to a scientist for outstanding contributions to the field of solar astronomy.

Dr. Scherrer has certainly made contributions to solar physics. He has measured and studied the Sun's magnetic field for 50 years. As important, he has encouraged others to use his data as well. He has also worked in helioseismology, both measuring the velocities of the Sun's surface and the theory of ow those measurements tell us something about the Sun. It is hard to know what our field would look like if he hadn't been around.

Congratulations Phil!

Listening to the Sun

Ever wish you could listen to SDO data? We have developed new ways to do just that!

This week the American Astronomical Society and the AAS Solar Physics Division had a joint meeting in St Louis. Astronomers and solar physicists got together to discuss our latest papers on understanding the Sun and universe.

Two of those papers were "Listening to the Sun" (by Kyle Ingram-Johnson, W. Dean Pesnell, and Kevin Addison) and "Listening to the Sun: the Sonification of Solar Harmonics Project" (by tim larson, Seth Shafer, and Elaine diFalco). Both papers allow you hear different kinds of SDO data. They were presented as iPosters, so they are available at the links below for others to read through and enjoy.

This paper converts several solar indices to sound before sonifying AIA images in three ways. You can listen to the entire image, small subsets of the image, and a series of images that shows a filament liftoff. We used a special math curve called a Hilbert curve to walk around the image and convert the pixels values into a set that can be then converted to sound. You should listen to the difference between the full image sonified with a Hilbert curve and sonified with a left-right scan. You will see a big difference.

The next paper shifts HMI sound waves from their very low frequency of about 3 mHz to about 3 kHz so you can hear the tones.

You are working to allow you to sonify images, both the entire image and as subsets, on the SDO website. Look for that new feature in the future.

Until then, please enjoy listening to the Sun!

Momentum Management Maneuver #34 Today

SDO will execute Momentum Management Maneuver #34 (MM#34) today from 1845-1915 UTC (2:45-3:15 pm ET). During a maneuver the science data may be unavailable or blurred.

SDO Maneuvers Today

SDO will execute two calibration maneuvers today. The EVE Field of View maneuver will run from 1315-1600 UTC (9:15 am-12 noon ET). The HMI/AIA Flatfield maneuver will then run from 1630-1907 UTC (12:30 pm-3 pm ET). During the maneuvers images may be blurred or absent. These maneuvers were delayed to provide data during the perihelion passage of the Parker Solar Probe earlier this month.

SDO Plans for the Next Eight Months

Significant events in SDO's timeline are below. Calibration maneuvers are still being scheduled as we await the launch of CLASP-2 at White Sands and for the completion of the second perihelion pass of Parker Solar Probe.

• 01 May 2019 @1845 UTC (1445 ET) – Momentum Management Maneuver #34
• 19 Jul 2019 @0443 UTC (0043 ET) – First Handover Begins and Handover Season Starts (-Z HGA Active Prior)
• 08 Aug 2019 @0709 UTC (0309 ET) – Fall Eclipse Season Starts
• 12 Aug 20194 @TBD – Momentum Management Maneuver #35 (Tentative Date)
• 28 Aug 2019 @2222 UTC (1822 ET) – Station Keeping Maneuver #19 (Tentative Date)
• 01 Sep 2019 @0659 UTC (0259 ET) – Fall Eclipse Season Ends
• 12 Sep 2019 @0515 UTC (0115 ET) – Last Handover Completes and Handover Season Ends (+Z HGA Active After)
• 28 Sep 2019 @2043-2116 UTC (1643-1717 ET) – Lunar Transit - Video to follow
• 11 Nov 2019 @1236-1802 UTC (0736-1302 ET) – Mercury Transit - Video to follow

That's a Transit!

The long lunar transit SDO saw last night was quite a show. Here's a movie in AIA 171 Å from March 6, 2000 UTC, to March 7, 0400 UTC (March 6, 3:00-11:00 pm ET) showing the entire transit. The Moon touched the limb of the Sun at 2200 UTC and finally left the solar disk at 0207 UTC). During the transit the Sun moves in the frame as the spacecraft and telescopes cool and shiver in the lunar shadow.

Congratulations to the flight dynamics team for predicting a beautiful display of orbital mechanics.

Station Keeping Maneuver #18 Today

SDO will perform station keeping maneuver #18 (SK#18) today from 2225-2300 UTC (5:25-6:00 pm ET). During this time SDO data may be blurry or missing. These maneuvers are performed to keep SDO within the longitude limits assigned to our geosynchronous orbit. I'm sure our neighbors appreciate us staying inside the box!