Why are some Sun images an hour old?
Each spacecraft publishes on its own schedule. The time on each image shows when it was taken (in UT).
The Sun views come straight from NASA's SDO, the ESA/NASA SOHO mission and NOAA's GOES-19 and SWFO-L1 spacecraft. Each publishes new images on its own schedule:
- SDO images are usually less than an hour old.
- SOHO's LASCO coronagraphs often lag by an hour or more.
- NOAA's SUVI and CCOR images update every few minutes to every 15 minutes.
The time printed on each image is when it was taken, in Universal Time (UT). The time-lapse saves one image of each view every hour.