|See also Gazetteer of Planetary Nomenclature|
The Mare Nubium ( Latin for "sea of clouds") is one of the seven larger lunar seas (an old lowland covered with solidified magma or lava ) on the Earth's moon . It is located in the southwest quadrant of the visible front of the moon and can already be clearly seen with the naked eye as a dark, frayed spot: in the so-called " moon face " it forms the "mouth" that is slightly warped to the left.
Its slightly undulating plane is approximately circular and has an average diameter of 715 km - about a fifth of the moon's diameter . From the large, north-west adjoining Oceanus Procellarum , it can be clearly seen as a distinctive foothill, but is separated from it by the small Mare Cognitum and some crater-interspersed "mainland" strips ( ridges ). The selenographic coordinates of its center are 21 ° 18 'south, 16 ° 36' west.
Morphology in the shadow
The somewhat wavy structure of the Mare Nubium, on which relatively few meteorites hit after its formation, is particularly evident in the telescope 1–2 days after the half moon ( first or last quarter ) when the area is only grazed by sunlight. At the eastern edge (right) of the Mare Nubium z. For example, the stepped terrain of the Rupes Recta is very clearly visible, which the selenographer Hieronymus Schroeter called the “Long Wall” 200 years ago because he overestimated its steepness due to the long shadows. Another 1-2 days later, the sidelight of the terminator reaches the west side of the Mare and brings out the diverse structures of the Bullialdus and Gassendi craters - at the hilly transition to the Mare Humorum .
This lunar landscape is a particular pleasure for geologically interested amateur astronomers , because different line structures and terraced terrain levels of the old lava cover and the jagged crater edges cast interesting shadows and thus also allow special height measurements . The aforementioned H. Schroeter and the Viennese astronomer Josef Hopmann built the height system of the moon on such measurements .
In September 2013, astronomers observed the impact of a small asteroid in Mare Nubium.
- Tilmann Althaus: Asteroid the size of a refrigerator struck the moon (September 11, 2013) Spektrum.de, February 25, 2014, accessed October 5, 2015
- A large lunar impact blast on September 11th 2013 arxiv.org, accessed February 28, 2014