I noticed this in our sidebar SDO solar image and grabbed it.
It has happened before, last year.
From this NASA story
Image Credit: SDO/NASA
NASA’s Solar Dynamics Observatory recorded its first lunar transit when the moon passed directly between the spacecraft and the sun.
In this newly released image, the dark edge of the moon forms a partial eclipse of the sun. This sharp edge can be used to help calculate the effects of light diffraction on the telescope’s optics, allowing operators to correct for this effect.
Onboard the SDO is the Helioseismic and Magnetic Imager instrument. This measures magnetic fields, as well as visible ripples on the surface of the sun caused by the sun’s convection zone. This data helps researchers understand our star’s influence on Earth and near-Earth space.
Watch the progress on our WUWT solar page here
If somebody wants to make a movie I’ll post it later.