Which constellation is named after a table mountain?

Mensa is the constellation named after Table Mountain. Its name comes from the Latin word for “table,” referring to the flat-topped mountain overlooking Cape Town, South Africa.

French astronomer Nicolas-Louis de Lacaille created Mensa in the 18th century while mapping the southern skies from the Cape of Good Hope. He originally called it Mons Mensae, or “Table Mountain.” Lacaille associated the nearby Magellanic Clouds with clouds that often gather around Table Mountain, creating the image of a celestial mountain beneath a cloudy sky.

Mensa is one of the 88 constellations officially recognized by the International Astronomical Union. It lies close to the south celestial pole and covers about 153.5 square degrees, making it the 75th-largest constellation. It is also notably faint: Alpha Mensae, its brightest star, is only barely visible under suburban skies.

A common mix-up is assuming Mensa refers to a dining table or an astronomical instrument. The name specifically commemorates South Africa’s Table Mountain, and Mensa is the only one of Lacaille’s 14 new constellations named for a natural landmark rather than a scientific instrument.