16:17 UT (11:17 UT) – The transit ends with a bang! – an M6.6 flare peaked at 16:11 from AR11967. These images are from just before the flare peak at around 16:00 UT (11:00 EST) again in all 9 SDO/AIA wavelengths.
16:06 UT (11:06 EST) – Tail end of the transit ~15:45 UT, roughly 11 minutes left, shown with all 9 SDO/AIA wavelengths.
14:45 UT (9:45 EST) – Roughly 1 hour into the transit ~14:30 UT, shown with all 9 SDO/AIA wavelengths.
14:03 UT (9:03 EST) – The beginning of the transit in all 9 SDO/AIA wavelengths from ~13:45 UT.
Lunar transits are not uncommon for the Solar Dynamics Observatory (SDO).
From an earlier post – “Observations of lunar transits are very useful for SDO. They are used to better understand SDO’s pointing. Also, transits allow the SDO scientists to fine tune the telescopes. One problem with telescopes is stray light. If you look at the lunar disk it should be completely black. Close inspection reveals that is it not completely black. This is because a small amount of light not directly from the sun has made its way into the inside of the telescope. By studying how much the lunar disk deviates from being black, SDO scientists can measure and ultimately account for how much unwanted scattered light is making its way into the telescope.”
The SDO mission has observed many examples of the moon moving in front of the sun from the spacecraft’s viewpoint. Some transits are around 30 minutes but these transits are usually not longer than 1.5 hours. On January 30, 2014, from 13:31 – 15:56 UT (8:31 – 10:56 EST) SDO will observe an especially long lunar transit – that’s a duration of around 2.5 hours.
Here is a simulation showing the predicted observation of SDO’s extra long transit observation.
credit: NASA/SDO/Olivier Fehr