The lunar domes of Mare Insularum

[Nik271]

I have been trying to see the Hortensius domes for some time but somehow never picked the right moon phase. Last night the seeing was poor but the transparency was good and the phase was about right. The domes were showing reasonably well at x120 with my Skymax 127. In fact I noticed quite a few more scattered near Hortensius and Milichius.

Lunar domes are very subtle, with shallow slopes and so visible only when close to the terminator. The usual satellite maps of the moon don't show them well. Here the LAC series has an advantage as was drawn from visual observations by hand. The LAC charts 57 and 58 are the relevant ones. The following simulation from NASA gives some idea how the domes looked last night. I circled those I could see.

 

 

I think 10 hours earlier the illumination would have been perfect but still I'm happy to see them at all 🙂