It’s getting close to summer solstice. Nights are shorter and shorter, and there is also growing Moon in the sky – not a good time for deep sky observers at higher northern latitudes. We need to wait for the second half of July for some serious nights. So, let’s take a look at the Moon this time – at Theophilus and Posidonius craters 🙂
Seeing was not perfect at night of May, 31st, so among about dozen of pictures I decided to show only two. First one is Theophilus crater area.
This is the leftmost crater at the picture above. Together with Cyrillus and Catharina they form a prominent group of craters. Theophillus rim rises about 4200m above its floor. It was created in the Eratosthenian period, so it is pretty old. Its central mountain is 1400m high and has four summits. Both Cyrillus and Catharina are much older craters – it can be easily seen how these craters overlap each other. Little bit below this frame there is Apollo 16 landing site.
The largest crater in the next picture is Posidonius. Its rim is shallow and obscured and the interiors has been overlain by lava flow in the past. Crater floor is laced with rille system called Rimae Posidonius. In the lower right image part there is easily visible system of wrinkle ridges that parallel nearby shore. They are designated the Dorsa Smirnov. 5km diameter crater Very lies upon this ridge and it is 1km deep.
Images of Posidonius and Theophilus Moon craters above were made with Celestron SCT8″ telescope, TV x2 barlow lens, Baader IR pass filter and ASI290MM camera.