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The Great Eclipse August 21, 2017

 SOHO: EIT and LASCO Observations Plan

 Update: May 24, 2017

Science teams can request LASCO and EIT support for their individual observations. Please look over the information below regarding the Eclipse program.  If there are special observations or timings that you require, please send us an email to the LASCO Planner address below.  Be sure to include your name, time of totality, and your observation request.


Once we receive your request, we will add your information into the observation program.
Special requests are listed by the Observer as shown below.

Science Observing Team


Observation Summary

Sheeley & Penn et al. 

17:00-19:00 UT 

CATE Project - C2 @6minute cadence 


















Real-Time Images.

Real-Time images for LASCO and EIT will be made available for the Eclipse.  The images will be posted beginning at 1 solar rotation (July 26) for pre-eclipse object and informational planning.  Click the image for real-time images page.

real-time Images

Observation plan summary. 

 Eclipse observations are interleaved with the daily synoptic observing program of the EIT and LASCO instruments.

SOHO is in the middle of the telemetry Keyhole period during Eclipse day (Aug 16-23, 2017).  Please be aware. Our LASCO and EIT program is restricted to the keyhole data rate of 7.9 kbps (telemetry submode 5).

The synoptic program consists of C2 and C3 full field full resolution at a 12 minute cadence.
*note; during keyhole periods of submode 5 telemetry, C2 and C3 are using H-compression.
EIT synoptic sets in the 4 wavelengths are daily at a 12 hour cadence executed at 01:00 and 13:00 UT.

Supplementary Eclipse observation support.

August 20 & 22:   3:36 UT and 15:26 UT; C2, C3 color sequences

August 21:            03:36 UT C2, C3 color sequence.

                                11:42 UT C3 red
pB sequence
                                13:36 UT C2 red pB sequence.
                                14:36 UT C2, C3 color sequence.

                                15:18 UT C3 orange
pB sequence.
                                15:42 UT C2 orange pB sequence.

  [Eclipse period]  C3 clear/clear images lossless compression 16:18 UT.
                                C2 orange/clear images lossless compression 16:36 UT.
                                C2 orange/clear images at 6 minute cadence [Sheeley/Penn].
                                *all other C2 and C3 full resolution images are H5-compressed.

                                19:54 UT C2 red
pB sequence.
                                20:54 UT C2 orange pB sequence.
                                21:42 UT C3 red
pB sequence.
                                22:42 UT C3 orange pB sequence

Observation plan summary and timeline.  

Graphic representation of the LASCO eclipse observing plan.
Observations in C2, C3 and EIT are color coded. The
The instrument(s) data buffer is indicated in white showing
the submode 5 data usage. Click to enlarge the graphic.

2017_aug_21_eclipse_1day2 Graphic

Responsible NASA official: Joseph B. Gurman, Facility Scientist, Solar Data Analysis Center
+1 301 286-4767

NASA Goddard Space Flight Center
Solar Physics Branch / Code 671
Greenbelt, MD 20771