- Mauritania, officially the Islamic Republic of Mauritania (Arabic: الجمهورية الإسلامية الموريتانية, al-Jumhūrīyah al-Islāmīyah al-Mūrītānīyah), is a sovereign country in Northwest Africa. It is bordered by the Atlantic Ocean to the west, Western Sahara to the north and northwest, Algeria to the northeast, Mali to the east and southeast, and Senegal to the southwest. By land area Mauritania is the 11th-largest country in Africa and 28th-largest in the world; 90% of its territory is in the Sahara. Most of its population of some 4.3 million lives in the temperate south of the country, with roughly a third concentrated in the capital and largest city, Nouakchott, on the Atlantic coast.
- Local Group (Wikipedia)
The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly 3 megaparsecs (10 million light-years; 9×1022 metres), and a total mass of the order of 2×1012 solar masses (4×1042 kg). It consists of two collections of galaxies in a “dumbbell” shape: the Milky Way and its satellites form one lobe, and the Andromeda Galaxy and its satellites constitute the other. The two collections are separated by about 800 kpc (3×106 ly; 2×1022 m) and are moving toward one another with a velocity of 123 km/s. The group itself is a part of the larger Virgo Supercluster, which may be a part of the Laniakea Supercluster. The exact number of galaxies in the Local Group is unknown as some are occluded by the Milky Way; however, at least 80 members are known, most of which are dwarf galaxies.
