Eclipse Season #31 begins, featuring the Sun, Earth and Moon

SDO's 31st eclipse season begins at 07:21 UT on July 10, 2025, and will last until August 7.  SDO's orbit is geosynchronous, inclined relative to the Earth's axis so most of time SDO has a 24/7 view of the Sun.  However, there are times when SDO's orbit passes behind the Earth, and during these periods SDO experiences brief interruptions in its observations of the Sun.  On July 25 SDO will pass behind both the moon and the Earth on the same day!  

Because of the Earth's atmosphere, the Earth's edge appears diffuse in SDO images while the lunar edge is quite sharp.  Here are images from the the last SDO eclipse season to compare.  The left image shows a shadow caused by the Sun's light being blocked by the Earth on an SDO 1700 Å UV image.  The right image shows the sharp edge caused by the moon, which has little atmosphere.  

The Flare-ometer is at X-level again

Solar flares are classified using the X-ray brightness (see an explanation here), and "X class" flares are the strongest.  The sunspot and magnetic active region complex that produced many M-class and X-class flares last month is back, and the EVE "flare-ometer" is hitting the red zone again.  

EVE measures irradiance in the extreme ultraviolet (EUV), which are wavelengths slightly less energetic than X-rays. EUV variations in flux have a direct impact on the Earth's atmosphere and ionosphere, so EVE's measurements are essential for space weather forecasts.  

EVE has a special flare observation mode that is triggered autonomously onboard SDO.  EVE had 7 flare campaigns triggered in April, 8 in May, and so far there have been 8 in June. When combined with HMI and AIA, SDO is able to capture the magnetic structure and dynamics of space weather processes. 

Four Lunar Transits April-July 2025

SDO will see 4 lunar transits between April and July 2025. Two look like the Moon is just brushing by the Sun and one is pretty nice looking.
There are lunar transits on April 27, 2025 and April 28, 2025. Here are the movies from the SDO Flight Operations Team.

April 27; Moon covers 23% of the solar disk.

April 28; Moon covers 2% of solar disk.

May 25; Moon covers 4% of solar disk.

July 25; Moon covers 62% of solar disk.

The fourth will be the longest and deepest transit in the first half of 2025.

JSOC Repairs are Complete, Normal Data Services have Resumed

At 12 noon PT, 4 Feb 2025, the HMI/AIA JSOC at Stanford has resumed normal data services. A small fraction of the data files were lost and are being restored from a tape backup.

Congratulations to the Stanford Team for their rapid repair of the JSOC!

JSOC Update and Schedule of Events

The JSOC repair continues. This week we have started serving 15 min cadence images from AIA and HMI for Space Weather operators and others at the SDO website https://sdo.gsfc.nasa.gov. Stanford continues to rebuild the full capability of the JSOC. Several pieces of electronics are delayed by the dreaded supply-chain issues we all thought were finally behind us. All of the science data will be available for available once the JSOC is restored.

The JSOC may be off-line, but SDO continues making observations and collecting data about our Sun during the maximum of Solar Cycle 25.

SDO continues doing all of the usual things of a satellite mission:

1. 12/18/24: Delta-H #51
2. 01/08/25: EVE Cruciform
3. 01/10/25: Eclipse Season #30 Starts
4. 01/15/25: EVE FOV (@1400 UTC) and HMI/AIA Flatfield (@1715 UTC) Calibration Manuvers
5. 01/16/25: HGA Handover Season #30 Starts
6. 01/22/25: Stationkeeping Maneuver #30 (@2320 UTC)
7. 01/29/25: AIA GT/PZT Calibration (images may shake a little)
8. 02/05/25: Eclipse Season #30 Ends
9. 02/16/25: HGA Handover Season #30 Ends