I have been digging up my old astronomy gear which has not seen the night sky for many years.  The first target of interest, and one of my favorites, is Earth’s Moon.  I am picking up where I left off a long time ago to photograph the Moon’s surface hampered, as always, by Florida’s turbulent skies that make the seeing rather questionable.  “Seeing”, as astronomy buffs define it, is the turbulent airflows inherent in the Earth’s atmosphere that degrade an image causing blurring, twinkling, or some other distortion.  It’s the reason telescopes are put into space or placed high on mountaintops; it’s to get above the turbulent air. Cloudy skies are bad enough, but clear skies can be just as bad.  A good rule of thumb in clear skies is to observe how vigorously the stars twinkle.  The more twinkling, the worse the seeing as rivers of air flow overhead causing loss of detail in any object observed through the turbulence.

My latest image of the Moon taken around the region of Mare Nectaris suffers from a loss of sharpness due to the bad seeing on a very windy night following the passage of the tropical storm. Mare Nectaris is a large lava-filled basin. Of interest is Fracastorius, a crater that had part of its wall breached and the interior flooded with lava.

Here is the same image with some of the features labeled and a little information about each one:

Beaumont – Crater – Diameter: 50.69 KM

Bohnenberger – Crater – Diameter: 31.74 KM 

Capella – Crater – Diameter: 48.13 KM

Catharina – Crater – Diameter: 98.77 KM

Cyrillus – Crater – Diameter: 98.09 KM

Fracastorius – Crater inundated by lava from Mare Nectaris – Diameter: 120.58 KM

Isidorus – Crater – Diameter: 41.39 KM

Lindenau – Crater – Diameter: 53.08 KM

Mädler – Crater – Diameter: 27.58 KM

Mare Nectaris (Sea of Nectar) – Diameter: 339.39 KM

Mare Tranquillitatis (Sea of Tranquility) – Diameter: 875.75 KM

Montes Pyrenaeus – Mountain range, named after the Pyrenees in Europe – 

Piccolomini – Crater – 87.58 KM

Polybius – Crater – 40.81 KM

Rosse – Crater – 11.43 KM

Rothmann – Crater – 41.67 KM

Rupes Altai – Scarp, named after the Altai Mountains in Asia – 427 KM in length

Sinus Asperitatis (Bay of Asperity) – Named for its rough lava surface 

Stiborius – Crater – Diameter: 43.76 KM

Theophilus – Crater – Diameter: 98.59 KM

Torricelli – Crater – Diameter: 30.87 KM

Lunar surface data from the Gazetteer of Planetary Nomenclature, International Astronomical Union Working Group for Planetary System Nomenclature, USGS, and NASA.

The box contains the approximate region shown in the images above.